This study evaluated the safety and efficacy of ablation for atrioventricular nodal reentrant tachycardia (AVNRT) using 3D electroanatomic mapping (EAM) with an irrigated ablation catheter, aiming for a minimal or zero fluoroscopic approach. The study included 50 patients who underwent AVNRT ablation. Acute success was 100% and mid-term success at 12 months was 96%. The average fluoroscopy time was very low at 0.63 minutes and 88% of procedures used no fluoroscopy at all. Catheter stability during radiofrequency ablation was high, with a standard deviation below 1.2 mm in all axes. No major complications occurred, demonstrating that AVNRT ablation can be
This document discusses the management of asymptomatic Wolff-Parkinson-White (WPW) syndrome. It outlines the risks of sudden cardiac death even in asymptomatic patients and challenges the approach of "leaving the patient alone." The document recommends using risk stratification to identify high-risk asymptomatic patients, such as those with a short accessory pathway effective refractory period (<250ms) or shortest pre-excited RR interval during induced atrial fibrillation (<250ms). For low-risk asymptomatic patients, close monitoring is recommended, while electrophysiological study with potential ablation is recommended for higher risk patients due to the risk of sudden cardiac death. Long-term studies show catheter ablation significantly reduces risks of malignant arrhythmias compared to
Basics of Electrophysiologic study, part 1 (2020)salah_atta
An electrophysiologic study involves inserting electrode catheters into the heart to record electrical activity and induce arrhythmias. The document discusses:
1. The procedure involves placing catheters in the heart to record electrograms from the atria, His bundle, ventricles and coronary sinus.
2. The aims are diagnostic to evaluate arrhythmias and bradycardias, and therapeutic for ablation of arrhythmias.
3. Key measurements taken include intervals between P waves, His bundle activation and QRS complex to identify conduction abnormalities.
4. Tracings are analyzed to determine the rhythm, sequence of activation, effects of pacing, and identify arrhythmia mechanisms like accessory pathways
This document discusses various types of arrhythmias including their mechanisms, diagnosis using electrophysiologic studies, and management. It covers topics such as AV nodal reentrant tachycardia, orthodromic reciprocating tachycardia, atrial flutter, atrial tachycardia, Wolff-Parkinson-White syndrome, and differentiation of arrhythmias using pacing techniques during electrophysiology studies. The role of EPS in establishing mechanisms of arrhythmias and guiding treatment is emphasized.
This document provides information about electrophysiologic studies (EPS), including the purpose, requirements, procedures, and how to read EPS tracings. An EPS involves placing electrode catheters in the heart to record electrical activity and stimulate heart tissues to evaluate arrhythmias. Key aspects of an EPS include determining the sequence of impulse propagation in the atria, ventricles, and conduction system during normal sinus rhythm, pacing, and arrhythmias to diagnose arrhythmia type and location.
Tachyarrhythmias 2020 (for the undergraduates)salah_atta
This document provides an overview of tachyarrhythmias. It defines tachyarrhythmias as abnormal heart rhythms with a heart rate exceeding 100 beats per minute. The document classifies and describes various types of tachyarrhythmias including extrasystoles, sinus tachycardia, supraventricular tachycardias such as AV nodal reentrant tachycardia, atrial fibrillation, and ventricular tachycardias. It discusses the mechanisms, clinical presentations, diagnostic tools and management options for these arrhythmias.
Cardiac arrhythmias and mapping techniquesSpringer
This document provides an overview of clinical cardiac electrophysiology. It discusses the history and development of the field, including the first recordings of intracardiac electrograms in the 1940s-1960s and the development of programmed electrical stimulation in the 1960s-1970s which allowed investigation of arrhythmia mechanisms. It describes the methodology used in electrophysiology studies, including equipment for recording cardiac activity and electrical stimulation, as well as study protocols for evaluating conduction intervals, refractory periods, and inducing/terminating arrhythmias. It outlines the diagnostic and therapeutic indications for electrophysiology studies in evaluating bradycardias, tachycardias, guiding catheter ablation and medical therapy, and risk stratification of conditions like WPW
Early results of RF ablation in assiut universitysalah_atta
1) The document reports on the early experience of a cardiology team in Assiut, Egypt performing radiofrequency catheter ablation to treat cardiac arrhythmias.
2) Over 12 months, the team successfully treated 20 patients with various arrhythmias including AV nodal reentrant tachycardia, accessory pathway dependent tachycardia, and atrial flutter.
3) The procedures achieved a high primary success rate of 100% with only one recurrence during follow up, demonstrating the effectiveness of bringing this treatment to patients in upper Egypt.
This document discusses the management of asymptomatic Wolff-Parkinson-White (WPW) syndrome. It outlines the risks of sudden cardiac death even in asymptomatic patients and challenges the approach of "leaving the patient alone." The document recommends using risk stratification to identify high-risk asymptomatic patients, such as those with a short accessory pathway effective refractory period (<250ms) or shortest pre-excited RR interval during induced atrial fibrillation (<250ms). For low-risk asymptomatic patients, close monitoring is recommended, while electrophysiological study with potential ablation is recommended for higher risk patients due to the risk of sudden cardiac death. Long-term studies show catheter ablation significantly reduces risks of malignant arrhythmias compared to
Basics of Electrophysiologic study, part 1 (2020)salah_atta
An electrophysiologic study involves inserting electrode catheters into the heart to record electrical activity and induce arrhythmias. The document discusses:
1. The procedure involves placing catheters in the heart to record electrograms from the atria, His bundle, ventricles and coronary sinus.
2. The aims are diagnostic to evaluate arrhythmias and bradycardias, and therapeutic for ablation of arrhythmias.
3. Key measurements taken include intervals between P waves, His bundle activation and QRS complex to identify conduction abnormalities.
4. Tracings are analyzed to determine the rhythm, sequence of activation, effects of pacing, and identify arrhythmia mechanisms like accessory pathways
This document discusses various types of arrhythmias including their mechanisms, diagnosis using electrophysiologic studies, and management. It covers topics such as AV nodal reentrant tachycardia, orthodromic reciprocating tachycardia, atrial flutter, atrial tachycardia, Wolff-Parkinson-White syndrome, and differentiation of arrhythmias using pacing techniques during electrophysiology studies. The role of EPS in establishing mechanisms of arrhythmias and guiding treatment is emphasized.
This document provides information about electrophysiologic studies (EPS), including the purpose, requirements, procedures, and how to read EPS tracings. An EPS involves placing electrode catheters in the heart to record electrical activity and stimulate heart tissues to evaluate arrhythmias. Key aspects of an EPS include determining the sequence of impulse propagation in the atria, ventricles, and conduction system during normal sinus rhythm, pacing, and arrhythmias to diagnose arrhythmia type and location.
Tachyarrhythmias 2020 (for the undergraduates)salah_atta
This document provides an overview of tachyarrhythmias. It defines tachyarrhythmias as abnormal heart rhythms with a heart rate exceeding 100 beats per minute. The document classifies and describes various types of tachyarrhythmias including extrasystoles, sinus tachycardia, supraventricular tachycardias such as AV nodal reentrant tachycardia, atrial fibrillation, and ventricular tachycardias. It discusses the mechanisms, clinical presentations, diagnostic tools and management options for these arrhythmias.
Cardiac arrhythmias and mapping techniquesSpringer
This document provides an overview of clinical cardiac electrophysiology. It discusses the history and development of the field, including the first recordings of intracardiac electrograms in the 1940s-1960s and the development of programmed electrical stimulation in the 1960s-1970s which allowed investigation of arrhythmia mechanisms. It describes the methodology used in electrophysiology studies, including equipment for recording cardiac activity and electrical stimulation, as well as study protocols for evaluating conduction intervals, refractory periods, and inducing/terminating arrhythmias. It outlines the diagnostic and therapeutic indications for electrophysiology studies in evaluating bradycardias, tachycardias, guiding catheter ablation and medical therapy, and risk stratification of conditions like WPW
Early results of RF ablation in assiut universitysalah_atta
1) The document reports on the early experience of a cardiology team in Assiut, Egypt performing radiofrequency catheter ablation to treat cardiac arrhythmias.
2) Over 12 months, the team successfully treated 20 patients with various arrhythmias including AV nodal reentrant tachycardia, accessory pathway dependent tachycardia, and atrial flutter.
3) The procedures achieved a high primary success rate of 100% with only one recurrence during follow up, demonstrating the effectiveness of bringing this treatment to patients in upper Egypt.
Introduction to Electrophysiology - Supraventricular Tachycardias (1/4 lectures)Jose Osorio
What is cardiac Electrophysiology?
This presentation will cover basics of EP. It is Part 1 of 4 lectures about EP.
Part 1 - basics of EP and Supraventricular Tachycardias (SVT)
Part 2 - Ventricular arrhythmias and Cardiac Devices
Part 3 - Afib
Part 4 - EKG
This document provides information about pulseless electrical activity (PEA), including its definition, potential causes, treatment guidelines, and post-cardiac arrest care. PEA is defined as spontaneous cardiac electric activity without sufficient blood flow or organ perfusion. Common causes of PEA include things like cardiac tamponade, pulmonary embolism, hypovolemia, hyperkalemia, acidosis, and myocardial infarction. Treatment follows ACLS protocols, including CPR, epinephrine, identifying and treating the underlying cause, and post-cardiac arrest care focused on managing post-cardiac arrest syndrome if return of spontaneous circulation is achieved.
Why seizure not just epilepsy as it used to?SolidaSakhan
The document discusses the differences between syncope and seizures. Syncope is a transient loss of consciousness due to low blood flow to the brain that results in a brief loss of muscle tone, while seizures involve abnormal electrical activity in the brain. Key differences include triggers, motor activity during the episode, and recovery time. A thorough history and physical exam are important for differentiating the two, and tests like EEG, imaging, and cardiac monitoring may also provide useful information. Misdiagnosis can have negative health and psychosocial consequences.
The document provides an overview of cardiac electrophysiology studies. It discusses the goals of EP studies which include making accurate diagnoses of arrhythmias, establishing causes of symptoms like syncope, evaluating risk of sudden cardiac death, and guiding therapy. It covers indications for EP studies including diagnostic evaluation of bradyarrhythmias, tachyarrhythmias, and unexplained syncope, as well as risk stratification. The document describes the procedure preparation, equipment used, catheter placement in the heart, and electrophysiologic recordings obtained during EP studies.
This document summarizes presentations at the 5th Annual Scientific Cambodian Heart Association Congress regarding narrow complex tachycardias (NCTs). It presents two case studies of patients who presented with NCTs but were found to have ventricular tachycardia (VT) rather than supraventricular tachycardia (SVT) through electrophysiological study. Both patients had histories of myocardial infarction and ventricular scarring. The document cautions that NCTs can occasionally be VT, especially in patients with prior heart attacks, and recommends electrophysiological study to determine tachycardia origin when the mechanism is unclear.
Long term post Ventricular tachycardia ablation guided by non contact mapping...salah_atta
This study assessed radiofrequency catheter ablation guided by non-contact mapping for treatment of monomorphic ventricular tachycardia after myocardial infarction. Fifteen patients underwent either targeted ablation of exit sites and areas of slow conduction (Group I, 7 patients) or substrate modification with linear ablation lesions (Group II, 8 patients). Acute success rates were high for both groups. Long term success was also good, with no recurrence of ablated ventricular tachycardias during follow up for most patients. Substrate modification using linear ablation guided by non-contact mapping showed promise for preventing reinduction of arrhythmias.
Atrial flutter is a reentrant tachycardia involving the right atrium. There are two main types - typical atrial flutter which revolves counterclockwise around the tricuspid annulus, and reverse typical atrial flutter which revolves clockwise. Catheter ablation aims to create a continuous linear lesion across the cavotricuspid isthmus to block conduction and terminate the arrhythmia. Successful ablation is confirmed by the inability to induce flutter and demonstration of bidirectional conduction block across the ablation line.
How to perform and interpret entrainment pacing BasicsBenjamin Jacob
This document provides information on entrainment pacing, including:
1) Entrainment pacing involves accelerating the rate of a tachycardia to a faster pacing rate and resuming the intrinsic tachycardia rate when pacing stops. It allows study of arrhythmia origins and pathways.
2) For entrainment to occur, there must be a gap in excitability during the tachycardia for a pacing stimulus to be delivered without terminating the arrhythmia.
3) Entrainment can be identified by constant fusion of paced and tachycardia complexes except the last paced beat, or progressive fusion at different pacing rates showing changing morphology from tachycardia to
This document discusses techniques used in electrophysiology studies to assess cardiac conduction and diagnose arrhythmias. It describes:
- Normal cardiac activation sequences during sinus rhythm, pacing, and induced rhythms.
- Measurement of basic conduction intervals like AH, HV, and refractory periods which provide diagnostic information.
- Programmed electrical stimulation techniques like atrial and ventricular pacing, extrastimuli, and burst/ramp pacing which can induce and analyze arrhythmias.
- How these techniques characterize tissue properties, activation sequences, and help terminate tachycardias to establish diagnoses.
AV nodal reentrant tachycardia (AVNRT), or atrioventricular nodal reentrant tachycardia, is a type of tachycardia (fast rhythm) of the heart. It is a type of supraventricular tachycardia (SVT), meaning that it originates from a location within the heart above the bundle of His. AV nodal reentrant tachycardia is the most common regular supraventricular tachycardia. It is more common in women than men (approximately 75% of cases occur in females). The main symptom is palpitations. Treatment may be with specific physical maneuvers, medication, or, rarely, synchronized cardioversion. Frequent attacks may require radiofrequency ablation, in which the abnormally conducting tissue in the heart is destroyed.
AVNRT occurs when a reentry circuit forms within or just next to the atrioventricular node. The circuit usually involves two anatomical pathways: the fast pathway and the slow pathway, which are both in the right atrium. The slow pathway (which is usually targeted for ablation) is located inferior and slightly posterior to the AV node, often following the anterior margin of the coronary sinus. The fast pathway is usually located just superior and posterior to the AV node. These pathways are formed from tissue that behaves very much like the AV node, and some authors regard them as part of the AV node.
The fast and slow pathways should not be confused with the accessory pathways that give rise to Wolff-Parkinson-White syndrome (WPW syndrome) or atrioventricular reciprocating tachycardia (AVRT). In AVNRT, the fast and slow pathways are located within the right atrium close to or within the AV node and exhibit electrophysiologic properties similar to AV nodal tissue. Accessory pathways that give rise to WPW syndrome and AVRT are located in the atrioventricular valvular rings. They provide a direct connection between the atria and ventricles, and have electrophysiologic properties similar to ventricular myocardium.
Atrial tachycardia can originate from focal sites in the atria through mechanisms like automaticity, triggered activity, or microreentry, or can involve macroreentrant circuits circulating around anatomical barriers; focal atrial tachycardias are identified by characteristics like initiation with pacing or termination with adenosine while macroreentrant atrial tachycardias involve larger reentry circuits; the site of origin of atrial tachycardia can be localized using electrocardiographic criteria like the morphology and polarity of P-waves.
This document describes the technique of radiofrequency ablation for atrioventricular nodal reentrant tachycardia (AVNRT). It discusses catheter positioning between the coronary sinus os and tricuspid valve for ablation. The areas targeted for slow and fast pathway ablation are shown. Progression of ablation sites from the coronary sinus os inferiorly and superiorly on the septum are presented. Acceptable ablation areas between the His catheter and roof of the coronary sinus are outlined to minimize heart block risks. A case of successful AVNRT ablation in a 73-year old woman is then presented, demonstrating induction of the arrhythmia and pace mapping to identify the slow pathway for ablation.
This document discusses how pacing can help during electrophysiology studies (EPS). It describes ventricular pacing and how it can show normal retrograde activation sequences or the presence of an accessory pathway. It also discusses ventricular refractory periods and how pacing can induce arrhythmias. The document then discusses assessing atrioventricular conduction, including basic conduction intervals and response to incremental atrial pacing. It notes the indications of infra-Hisian block and disease in the His-Purkinje system as potential reasons for permanent pacing in symptomatic patients.
This document discusses electrophysiological diagnosis and management of atrioventricular reentrant tachycardia (AVRT). It describes the historical discovery of Wolff-Parkinson-White syndrome and mechanisms of tachyarrhythmias including reentry. Characteristics of orthodromic and antidromic AVRT are provided along with techniques for evaluating accessory pathways including baseline observations, programmed stimulation, and catheter ablation. Precise localization of accessory pathways is important for successful ablation.
A 17-year-old male presented with recurrent episodes of rapid heart palpitations. During an episode, electrocardiography (ECG) showed a wide complex tachycardia. An electrophysiology study was performed, which induced the clinical tachycardia and identified it as an atrial flutter conducting with 2:1 block to the ventricles. Linear radiofrequency ablation of the cavo-tricuspid isthmus was performed to cut the reentry circuit, requiring 8 applications to achieve bidirectional block and render the tachycardia non-inducible.
Recurrent ventricular arrhythmia after cardiac surgerysalah_atta
This document discusses the management of post-cardiac surgery ventricular arrhythmias. It begins by outlining the objectives and importance of addressing ventricular arrhythmias after cardiac surgery. Some key points include that ventricular arrhythmias are seen in about 50% of patients after surgery but are generally not related to mortality if left ventricular function is good, while sustained ventricular tachycardia and fibrillation occur less commonly but are life-threatening. The document then covers the epidemiology, etiology, risk factors, diagnosis and treatment of different types of postoperative ventricular arrhythmias.
1. AVNRT and AVRT are types of supraventricular tachycardia involving abnormal pathways for electrical conduction between the atria and ventricles.
2. AVNRT is caused by a reentry circuit within the AV node, while AVRT involves an accessory pathway bypassing the AV node.
3. There are different subtypes of AVNRT and AVRT depending on which pathways are involved in the antegrade and retrograde directions. Typical AVNRT involves a slow-fast pathway while typical AVRT involves orthodromic conduction over an accessory pathway.
This document provides an overview of basic electrophysiology (EP) studies, which assess the heart's electrical system and conduction pathways. EP studies are used to diagnose and treat cardiac arrhythmias by characterizing atrial and ventricular properties, identifying accessory pathways, and guiding interventions like ablation. Key aspects covered include: indications for EP studies; equipment used; catheter placement; measurement of intervals like AH and HV; pacing protocols to assess refractory periods; and response patterns to extra stimuli.
This document discusses trans-septal puncture, which involves puncturing the septum between the right and left atria to access the left side of the heart. It outlines the evolving indications for trans-septal puncture including interventions for mitral valve disease, closure of defects, left atrial procedures, and arrhythmia ablation. The key steps are reviewed - having the proper anatomical landmarks, hardware including sheaths and needles, and imaging guidance. Complications are discussed and how to successfully perform the puncture is summarized as being familiar with the anatomy, hardware, and vigilance for potential complications.
This document discusses atrioventricular nodal reentrant tachycardia (AVNRT), which accounts for about 2/3 of paroxysmal supraventricular tachycardia cases. It involves a dual pathway in the AV node allowing for a reentrant circuit. Management in the acute setting includes vagal maneuvers, adenosine, or calcium channel blockers, while long term management may involve medications like digoxin, beta blockers, or calcium channel blockers. Catheter ablation has a 95% success rate but a 1% risk of AV block, and is recommended for severe, frequent, or medication-resistant cases.
Catheter ablation of Idiopatic ventricular tachycardiaMarina Mercurio
1. The study assessed the feasibility, success rate, and safety of catheter ablation for idiopathic ventricular tachycardia without the use of fluoroscopy.
2. Nineteen patients underwent ablation guided by electroanatomical mapping and intracardiac echocardiography without fluoroscopy.
3. The procedure was successful in all patients with no complications. At 18-month follow up, recurrences occurred in two patients. The study demonstrates catheter ablation for idiopathic VT can be performed safely and effectively without fluoroscopy.
Thermal Ablation of Renal Tumors under Ultrasound Guidance and Conscious Seda...asclepiuspdfs
Purpose: Computed tomography (CT) guidance and general anesthesia have recently been recommended as the approach of choice for percutaneous ablation of small renal cell carcinoma (RCC), whereas ultrasound (US) guidance and conscious sedation have been tagged as inadequate. Aim of the study was to assess the safety and effectiveness of percutaneous thermal ablation of small RCC under ultrasound (US)-guidance and conscious sedation. Methods: The records of 74 patients with small RCC (≤5 cm), who underwent US-guided thermal ablation under conscious sedation were retrospectively reviewed. Conscious sedation was usually induced by means of intravenous bolus of midazolam 50–100 μg/kg plus continuous infusion of a 25 μg/mL solution of remifentanil at a rate of 0.05 μg/kg/min. Technical success, technical efficacy, local tumor progression (LTP), primary and secondary efficacy rates, complication rate, and 1-, 3-, and 5-year survival rates were analyzed.
Introduction to Electrophysiology - Supraventricular Tachycardias (1/4 lectures)Jose Osorio
What is cardiac Electrophysiology?
This presentation will cover basics of EP. It is Part 1 of 4 lectures about EP.
Part 1 - basics of EP and Supraventricular Tachycardias (SVT)
Part 2 - Ventricular arrhythmias and Cardiac Devices
Part 3 - Afib
Part 4 - EKG
This document provides information about pulseless electrical activity (PEA), including its definition, potential causes, treatment guidelines, and post-cardiac arrest care. PEA is defined as spontaneous cardiac electric activity without sufficient blood flow or organ perfusion. Common causes of PEA include things like cardiac tamponade, pulmonary embolism, hypovolemia, hyperkalemia, acidosis, and myocardial infarction. Treatment follows ACLS protocols, including CPR, epinephrine, identifying and treating the underlying cause, and post-cardiac arrest care focused on managing post-cardiac arrest syndrome if return of spontaneous circulation is achieved.
Why seizure not just epilepsy as it used to?SolidaSakhan
The document discusses the differences between syncope and seizures. Syncope is a transient loss of consciousness due to low blood flow to the brain that results in a brief loss of muscle tone, while seizures involve abnormal electrical activity in the brain. Key differences include triggers, motor activity during the episode, and recovery time. A thorough history and physical exam are important for differentiating the two, and tests like EEG, imaging, and cardiac monitoring may also provide useful information. Misdiagnosis can have negative health and psychosocial consequences.
The document provides an overview of cardiac electrophysiology studies. It discusses the goals of EP studies which include making accurate diagnoses of arrhythmias, establishing causes of symptoms like syncope, evaluating risk of sudden cardiac death, and guiding therapy. It covers indications for EP studies including diagnostic evaluation of bradyarrhythmias, tachyarrhythmias, and unexplained syncope, as well as risk stratification. The document describes the procedure preparation, equipment used, catheter placement in the heart, and electrophysiologic recordings obtained during EP studies.
This document summarizes presentations at the 5th Annual Scientific Cambodian Heart Association Congress regarding narrow complex tachycardias (NCTs). It presents two case studies of patients who presented with NCTs but were found to have ventricular tachycardia (VT) rather than supraventricular tachycardia (SVT) through electrophysiological study. Both patients had histories of myocardial infarction and ventricular scarring. The document cautions that NCTs can occasionally be VT, especially in patients with prior heart attacks, and recommends electrophysiological study to determine tachycardia origin when the mechanism is unclear.
Long term post Ventricular tachycardia ablation guided by non contact mapping...salah_atta
This study assessed radiofrequency catheter ablation guided by non-contact mapping for treatment of monomorphic ventricular tachycardia after myocardial infarction. Fifteen patients underwent either targeted ablation of exit sites and areas of slow conduction (Group I, 7 patients) or substrate modification with linear ablation lesions (Group II, 8 patients). Acute success rates were high for both groups. Long term success was also good, with no recurrence of ablated ventricular tachycardias during follow up for most patients. Substrate modification using linear ablation guided by non-contact mapping showed promise for preventing reinduction of arrhythmias.
Atrial flutter is a reentrant tachycardia involving the right atrium. There are two main types - typical atrial flutter which revolves counterclockwise around the tricuspid annulus, and reverse typical atrial flutter which revolves clockwise. Catheter ablation aims to create a continuous linear lesion across the cavotricuspid isthmus to block conduction and terminate the arrhythmia. Successful ablation is confirmed by the inability to induce flutter and demonstration of bidirectional conduction block across the ablation line.
How to perform and interpret entrainment pacing BasicsBenjamin Jacob
This document provides information on entrainment pacing, including:
1) Entrainment pacing involves accelerating the rate of a tachycardia to a faster pacing rate and resuming the intrinsic tachycardia rate when pacing stops. It allows study of arrhythmia origins and pathways.
2) For entrainment to occur, there must be a gap in excitability during the tachycardia for a pacing stimulus to be delivered without terminating the arrhythmia.
3) Entrainment can be identified by constant fusion of paced and tachycardia complexes except the last paced beat, or progressive fusion at different pacing rates showing changing morphology from tachycardia to
This document discusses techniques used in electrophysiology studies to assess cardiac conduction and diagnose arrhythmias. It describes:
- Normal cardiac activation sequences during sinus rhythm, pacing, and induced rhythms.
- Measurement of basic conduction intervals like AH, HV, and refractory periods which provide diagnostic information.
- Programmed electrical stimulation techniques like atrial and ventricular pacing, extrastimuli, and burst/ramp pacing which can induce and analyze arrhythmias.
- How these techniques characterize tissue properties, activation sequences, and help terminate tachycardias to establish diagnoses.
AV nodal reentrant tachycardia (AVNRT), or atrioventricular nodal reentrant tachycardia, is a type of tachycardia (fast rhythm) of the heart. It is a type of supraventricular tachycardia (SVT), meaning that it originates from a location within the heart above the bundle of His. AV nodal reentrant tachycardia is the most common regular supraventricular tachycardia. It is more common in women than men (approximately 75% of cases occur in females). The main symptom is palpitations. Treatment may be with specific physical maneuvers, medication, or, rarely, synchronized cardioversion. Frequent attacks may require radiofrequency ablation, in which the abnormally conducting tissue in the heart is destroyed.
AVNRT occurs when a reentry circuit forms within or just next to the atrioventricular node. The circuit usually involves two anatomical pathways: the fast pathway and the slow pathway, which are both in the right atrium. The slow pathway (which is usually targeted for ablation) is located inferior and slightly posterior to the AV node, often following the anterior margin of the coronary sinus. The fast pathway is usually located just superior and posterior to the AV node. These pathways are formed from tissue that behaves very much like the AV node, and some authors regard them as part of the AV node.
The fast and slow pathways should not be confused with the accessory pathways that give rise to Wolff-Parkinson-White syndrome (WPW syndrome) or atrioventricular reciprocating tachycardia (AVRT). In AVNRT, the fast and slow pathways are located within the right atrium close to or within the AV node and exhibit electrophysiologic properties similar to AV nodal tissue. Accessory pathways that give rise to WPW syndrome and AVRT are located in the atrioventricular valvular rings. They provide a direct connection between the atria and ventricles, and have electrophysiologic properties similar to ventricular myocardium.
Atrial tachycardia can originate from focal sites in the atria through mechanisms like automaticity, triggered activity, or microreentry, or can involve macroreentrant circuits circulating around anatomical barriers; focal atrial tachycardias are identified by characteristics like initiation with pacing or termination with adenosine while macroreentrant atrial tachycardias involve larger reentry circuits; the site of origin of atrial tachycardia can be localized using electrocardiographic criteria like the morphology and polarity of P-waves.
This document describes the technique of radiofrequency ablation for atrioventricular nodal reentrant tachycardia (AVNRT). It discusses catheter positioning between the coronary sinus os and tricuspid valve for ablation. The areas targeted for slow and fast pathway ablation are shown. Progression of ablation sites from the coronary sinus os inferiorly and superiorly on the septum are presented. Acceptable ablation areas between the His catheter and roof of the coronary sinus are outlined to minimize heart block risks. A case of successful AVNRT ablation in a 73-year old woman is then presented, demonstrating induction of the arrhythmia and pace mapping to identify the slow pathway for ablation.
This document discusses how pacing can help during electrophysiology studies (EPS). It describes ventricular pacing and how it can show normal retrograde activation sequences or the presence of an accessory pathway. It also discusses ventricular refractory periods and how pacing can induce arrhythmias. The document then discusses assessing atrioventricular conduction, including basic conduction intervals and response to incremental atrial pacing. It notes the indications of infra-Hisian block and disease in the His-Purkinje system as potential reasons for permanent pacing in symptomatic patients.
This document discusses electrophysiological diagnosis and management of atrioventricular reentrant tachycardia (AVRT). It describes the historical discovery of Wolff-Parkinson-White syndrome and mechanisms of tachyarrhythmias including reentry. Characteristics of orthodromic and antidromic AVRT are provided along with techniques for evaluating accessory pathways including baseline observations, programmed stimulation, and catheter ablation. Precise localization of accessory pathways is important for successful ablation.
A 17-year-old male presented with recurrent episodes of rapid heart palpitations. During an episode, electrocardiography (ECG) showed a wide complex tachycardia. An electrophysiology study was performed, which induced the clinical tachycardia and identified it as an atrial flutter conducting with 2:1 block to the ventricles. Linear radiofrequency ablation of the cavo-tricuspid isthmus was performed to cut the reentry circuit, requiring 8 applications to achieve bidirectional block and render the tachycardia non-inducible.
Recurrent ventricular arrhythmia after cardiac surgerysalah_atta
This document discusses the management of post-cardiac surgery ventricular arrhythmias. It begins by outlining the objectives and importance of addressing ventricular arrhythmias after cardiac surgery. Some key points include that ventricular arrhythmias are seen in about 50% of patients after surgery but are generally not related to mortality if left ventricular function is good, while sustained ventricular tachycardia and fibrillation occur less commonly but are life-threatening. The document then covers the epidemiology, etiology, risk factors, diagnosis and treatment of different types of postoperative ventricular arrhythmias.
1. AVNRT and AVRT are types of supraventricular tachycardia involving abnormal pathways for electrical conduction between the atria and ventricles.
2. AVNRT is caused by a reentry circuit within the AV node, while AVRT involves an accessory pathway bypassing the AV node.
3. There are different subtypes of AVNRT and AVRT depending on which pathways are involved in the antegrade and retrograde directions. Typical AVNRT involves a slow-fast pathway while typical AVRT involves orthodromic conduction over an accessory pathway.
This document provides an overview of basic electrophysiology (EP) studies, which assess the heart's electrical system and conduction pathways. EP studies are used to diagnose and treat cardiac arrhythmias by characterizing atrial and ventricular properties, identifying accessory pathways, and guiding interventions like ablation. Key aspects covered include: indications for EP studies; equipment used; catheter placement; measurement of intervals like AH and HV; pacing protocols to assess refractory periods; and response patterns to extra stimuli.
This document discusses trans-septal puncture, which involves puncturing the septum between the right and left atria to access the left side of the heart. It outlines the evolving indications for trans-septal puncture including interventions for mitral valve disease, closure of defects, left atrial procedures, and arrhythmia ablation. The key steps are reviewed - having the proper anatomical landmarks, hardware including sheaths and needles, and imaging guidance. Complications are discussed and how to successfully perform the puncture is summarized as being familiar with the anatomy, hardware, and vigilance for potential complications.
This document discusses atrioventricular nodal reentrant tachycardia (AVNRT), which accounts for about 2/3 of paroxysmal supraventricular tachycardia cases. It involves a dual pathway in the AV node allowing for a reentrant circuit. Management in the acute setting includes vagal maneuvers, adenosine, or calcium channel blockers, while long term management may involve medications like digoxin, beta blockers, or calcium channel blockers. Catheter ablation has a 95% success rate but a 1% risk of AV block, and is recommended for severe, frequent, or medication-resistant cases.
Catheter ablation of Idiopatic ventricular tachycardiaMarina Mercurio
1. The study assessed the feasibility, success rate, and safety of catheter ablation for idiopathic ventricular tachycardia without the use of fluoroscopy.
2. Nineteen patients underwent ablation guided by electroanatomical mapping and intracardiac echocardiography without fluoroscopy.
3. The procedure was successful in all patients with no complications. At 18-month follow up, recurrences occurred in two patients. The study demonstrates catheter ablation for idiopathic VT can be performed safely and effectively without fluoroscopy.
Thermal Ablation of Renal Tumors under Ultrasound Guidance and Conscious Seda...asclepiuspdfs
Purpose: Computed tomography (CT) guidance and general anesthesia have recently been recommended as the approach of choice for percutaneous ablation of small renal cell carcinoma (RCC), whereas ultrasound (US) guidance and conscious sedation have been tagged as inadequate. Aim of the study was to assess the safety and effectiveness of percutaneous thermal ablation of small RCC under ultrasound (US)-guidance and conscious sedation. Methods: The records of 74 patients with small RCC (≤5 cm), who underwent US-guided thermal ablation under conscious sedation were retrospectively reviewed. Conscious sedation was usually induced by means of intravenous bolus of midazolam 50–100 μg/kg plus continuous infusion of a 25 μg/mL solution of remifentanil at a rate of 0.05 μg/kg/min. Technical success, technical efficacy, local tumor progression (LTP), primary and secondary efficacy rates, complication rate, and 1-, 3-, and 5-year survival rates were analyzed.
This document discusses a study that used dynamic CT angiography to evaluate enhancement patterns in the aorta and endoleaks after endovascular aneurysm repair (EVAR). The study found that maximum endoleak enhancement occurred at 22 seconds after contrast injection, while the highest endoleak detection rate was at 27 seconds. Conventional biphasic CT is insufficient for endoleak detection. Dynamic CT allowed detection of a 45% endoleak rate compared to typical rates of 20-30% and can help optimize EVAR follow-up imaging protocols.
This document discusses the role of MRI in assessing the thoracic aorta. It provides details on various MRI techniques used including CE-MRA, bSSFP, phase contrast, and black-blood sequences. It reviews clinical applications of MRI for thoracic aortic aneurysm, acute aortic syndromes, and large vessel vasculitis. MRI is presented as a good non-invasive alternative to CT for evaluation and serial imaging of thoracic aortic pathology due to lack of ionizing radiation and ability to characterize soft tissues and evaluate flow.
Vascular Access Part 1: Reducing risk and increasing catheter longevityCoda Change
Vascular access is essential for critically ill patients in the ICU. Nearly all patients will require some form of vascular device such as a PIVC, PICC, or CVC. While necessary, these devices carry risks of complications and infection if not inserted and managed properly. The document emphasizes that insertion is only a small part of device management, and more attention needs to be paid to the 99% of time the device is in use. It provides recommendations for proper device selection, insertion technique including use of ultrasound and micro-puncture, dressing and securement, and tip location to reduce risks and improve device longevity during the critical care stay.
This study assessed the safety and efficacy of steam vein sclerosis (SVS) for treating the great saphenous vein in 75 patients over 12 months. At 6 months, 96% of treated veins were successfully obliterated as assessed by duplex ultrasound. Quality of life scores improved significantly at 6 months for both physical and mental components. SVS achieved obliteration rates similar to other thermal ablation techniques with minimal post-operative pain and no major complications reported.
This document discusses the use of cardiac magnetic resonance imaging (cMRI) in catheter-based radiofrequency ablation procedures for cardiac arrhythmias. It begins by providing background on the evolution of ablation procedures from initial fluoroscopy-based navigation to current electroanatomical mapping systems combined with imaging modalities like cMRI. It then focuses on specific applications of cMRI for atrial fibrillation and ventricular tachycardia ablation, including assessing anatomy, characterizing tissue, integrating with mapping systems, and evaluating safety. Details are provided on cMRI protocols, quantification of fibrosis, and using cMRI to stage atrial fibrillation and predict ablation outcomes.
Ionizing radiation makes invasive cardiology procedures such as coronary angiography, percutaneous coronary intervention (PCI), and electrophysiologic diagnostics and therapeutics possible .
Radiation risks can be thought of as deterministic (effects after exceeding certain threshold, e.g., skin burns) or stochastic (a risk of an outcome is proportional to the dose received, e.g., malignancy or teratogenicity) .
Reducing the radiation exposure in the cardiac catheterization laboratory is important, especially as procedures are becoming more complex .
This document discusses various interventional therapies for resistant hypertension and renal artery stenosis, including renal sympathetic nerve ablation (RDN), baroreceptor activation therapy (BAT), and arteriovenous shunt creation. It provides details on techniques such as radiofrequency ablation and ultrasound ablation for RDN. It outlines trial results showing reductions in blood pressure from RDN, BAT, and arteriovenous shunts. It also discusses limitations of renal artery stenting based on recent trials. In summary, the document reviews novel interventional approaches for treating difficult cases of high blood pressure.
This study compared carotid-femoral pulse wave velocity (cfPWV) measurements obtained using a tonometer-based device and a cuff-based device with and without an adjustment algorithm. 88 participants across 4 centers underwent triplicate cfPWV measurement with each device. The unadjusted cuff-based method yielded lower cfPWV values than the tonometer-based method. Application of an algorithm to adjust for additional distance and transit time in the cuff-based method resulted in cfPWV values similar to the tonometer-based method. Analysis showed the adjusted cuff-based method provided comparable results to the tonometer-based method, validating the novel cuff-based assessment of cfPWV.
Future of RF Ablation: Continuous or Segmental?Vein Global
By: Alan M. Dietzek, MD, RVT, RPVI, FACS
Visit VeinGlobal at http://www.veinglobal.com/ for more presentations and videos on this topic, or for more information on venous disease news, education and research.
EVOLUTION IN CARDIAC RESYNCHRONIZATION THERAPY
Moving towards Leadless pacing mainly in cases with difficult coronary sinus anatomy, where placing the LV lead is difficult.
Echocardiographic guidance is critical for procedural success of paravalvular leak closure. Transesophageal echocardiography (TEE) and particularly three-dimensional echocardiography represent the gold standards. Fusion imaging provides real-time integration of three-dimensional echocardiography and X-ray fluoroscopy and can further facilitate spatial orientation, wire placement and device deployment. Intracardiac echocardiography (ICE) is a secondary approach possibly beneficial in selected cases.
The field of transcatheter mitral valve repair (TMVr) for
mitral regurgitation (MR) is rapidly evolving. Besides the
well-established transcatheter mitral edge-to-edge repair
approach, there is also growing evidence for therapeutic
strategies targeting the mitral annulus and mitral valve
chordae. A patient-tailored approach, careful patient
selection and an experienced interventional team is crucial
in order to optimise procedural and clinical outcomes. With
further data from ongoing clinical trials to be expected,
consensus in the Heart Team is needed to address these
complexities and determine the most appropriate TMVr
therapy, either single or combined, for patients with severe
MR
Transcranial Doppler Up Stroke Time Fraction (USTF) and Severe Carotid StenosisRoberto Hirsch
This study evaluated the use of transcranial Doppler (TCD) and duplex carotid ultrasound (DCU) to assess internal carotid artery (ICA) stenosis compared to angiography in 67 patients. Several TCD and DCU parameters including upstroke time fraction, peak systolic velocity, and common carotid artery asymmetry were predictive of >70% ICA stenosis on univariate analysis. Multivariate analysis found common carotid artery damping/asymmetry to have high odds of predicting severe stenosis. The study concludes that combined TCD and DCU can reliably determine ICA stenosis >70% and may provide physiological information beyond degree of stenosis.
This study evaluated the use of transcranial Doppler (TCD) and duplex carotid ultrasound (DCU) to assess internal carotid artery (ICA) stenosis compared to angiography in 67 patients. Several TCD and DCU parameters including upstroke time fraction, peak systolic velocity, and common carotid artery asymmetry were predictive of >70% ICA stenosis on univariate analysis. Multivariate analysis found common carotid artery damping/asymmetry to have high odds of predicting severe stenosis. The study concludes that combined TCD and DCU can reliably determine ICA stenosis >70% and may provide physiological information beyond degree of stenosis.
The document summarizes optimization of cardiac resynchronization therapy (CRT) post-implantation. It discusses:
1) Several methods for optimizing atrioventricular (AV) delay using echocardiography to maximize left ventricular filling, including Ritter's method, iterative method, and methods using left ventricular outflow tract velocity time integral or mitral inflow velocity time integral.
2) Methods for optimizing the ventricular-ventricular (VV) interval using electrocardiogram patterns.
3) Other optimization techniques including impedance cardiography, finger plethysmography, and algorithms using peak endocardial acceleration. Regular optimization is important to maximize benefits of CRT for selected patients.
Assessment of Intermediate Coronary Artery Lesion with Fractional Flow Reserv...Premier Publishers
Fraction flow reserve (FFR) is considered the gold standard for assessing intermediate coronary lesions. Retrospective data analyses showed variable relationship between intravascular ultrasound (IVUS) parameters and FFR results. This study aimed to determine the optimal minimum lumen area (MLA) by IVUS that correlates with FFR and to assess the correlation between two modalities in assessing intermediate coronary lesions. Methods: Fifty eight intermediate coronary lesions mainly located in proximal and mid segments of large main coronary vessels with RVD (3-4mm) were analyzed using both IVUS and FFR to assess the significance of coronary stenting and to determine the optimal IVUS-MLA that correlates with FFR value < 0.8. Results: IVUS-MLA ranged from 2.5 to 4.2 mm2 had a highly significant positive correlation with FFR value < 0.8 (p < 0.0001). Using the ROC curve analysis, IVUS-MLA < 3.9 mm2 (84.2% sensitivity, 80% specificity, area under curve (AUC) = 0.68) was the best threshold value for identifying FFR <0.8>< 0.8 in coronary vessels with RVD (3-4mm). Different MLA cutoffs should be used for different vessel diameters.
Similar to International Journal of Cardiovascular Diseases & Diagnosis (20)
A 5-year old boy, with an established diagnosis of a topic
dermatitis, previously treated by topical corticosteroids and emollient cream with a good improvement, developed widespread papules on his legs, hands and forearm that appeared 5 months ago.
Methods: Retrospectively, the file records of the patients who underwent sleeve gastrectomy were examined. Demographic features, Body Mass Index (BMI), the mouth opening, Mallampati score, thyromental distance, sternomental distance, neck circumference measurements and videolaryngoscopic examination results were recorded Results: In a total of 140 consecutive patients (58 male, 82 female) were included in the study. The mean age of the study participants was 35.40 ± 9.78 and the mean BMI of the patients was 44.33 ± 7.52 kg/m2
. The mean mouth opening of the patients was 4.82 ± 0.54 cm
and the mean neck circumference was 43.52 ± 4.66 cm. The mean thyromental distance was 8.02 ± 1.00 cm and the mean sternomental distance was16.58 ± 1.53 cm. Difficult intubation was determined in 8 (5.7%) patients. In logistic regression analysis, age (p : 0.446), gender (p : 0.371), BMI (p : 0.947), snoring (p : 0.567), sleep apnea (p : 0.218), mouth opening (p : 0.687), thyromental distance (p :0.557), sternomental (p : 0.596) and neck circumference (p : 0.838) were not the independent predictors of difficult intubation. However, Mallampati score (p : 0.001) and preoperative direct laryngoscopy findings (p : 0.037) performed in outpatient clinic were the significant
predictors of difficult intubation. Interestingly, all patients with grade 4 laryngoscopy findings had difficult intubation.
Introduction: Laparoscopic surgery has been performed in Mexico since 1989, but no reports about training tendencies exist. We conducted a national survey in 2015, and here we report the results concerning training characteristics during the surgical residence of the respondents. Materials and Methods: A prospective study was conducted through a survey questioning demographic data, laparoscopic training during pre and post surgical residency and other of areas of laparoscopic practice. The sample was calculated and survey piloted before
application. Special interest in this report was placed on type and quality of training received. Data are reported in percentages.
Heterotopic Ossification (HO) is defined as pathological bone formation at locations where bone normally does not exist. The
presence of HO has been found to be a rare complication after stroke in several studies, whereas there are only sporadic references relating HO to Cerebral Palsy (CP) and few for CP and stroke. No effective treatment for HO has yet been found, whereas the cellular and molecular mechanisms have not been completely understood. Therefore, increased awareness among physicians is required, as a challenge for early diagnosis and treatment. A case of a male patient with CP, who developed HO on the paretichip joint following an ischemic stroke is presented.
Objectives: To assess the practice of food hygiene and safety, and its associated factors among street food vendors in urban areas of Shashemane, West Arsi Zone, Oromia Ethiopia, 2019.
Methods: Cross-sectional study design was applied from December 28, 2019 to January 27, 2020. Data was collected from 120 food handlers, which were selected by purposive sampling techniques. Information was gathered from interview and field observation by conducting food safety survey and using questionnaires via face to face interview. The collected data was entered using Epi Data 3.1 and finally, it was analyzed using SPSS VERSION 20.
A Division I football player experienced acute posterior leg pain while playing. An ultrasound examination revealed an unusual injury - a complete rupture of the plantaris tendon mid-substance. This type of isolated plantaris tendon injury has rarely been reported. Ultrasound was useful for diagnosis and guided rehabilitation by monitoring healing over time. The athlete was able to return to full competition within 3 weeks through a progressive rehabilitation program focused on restoring range of motion and strength. This case suggests isolated plantaris tendon injuries may allow for faster return to play than other potential causes of posterior leg pain.
Type 1 Diabetes (T1D), is a severe disease, representing 5-10% of all reported cases of diabetes worldwide. Fulminant Type 1 Diabetes Mellitus (FT1D) is a subtype of type 1 diabetes mellitus that is largely characterized by the abrupt onset of Diabetic Ketoacidosis (DKA) and severe hyperglycemia without insulin defi ciency. Viral infections have been hypothesized to play a major role in the pathogenesis of Fulminant Type 1 Diabetes Mellitus (FT1D) through the complete and rapid destruction of pancreatic beta cells. Coxsackie viral infection has been detected in islets of 50% of the pancreatic tissue recovered from recent-onset Type 1 Diabetes (T1D) patients. In this report we have highlighted a case where the patient developed a Group B Coxsackie virus infection culminating in the development of Fulminant Type 1 Diabetes Mellitus (FT1D).
Methods: Cercariae are released by infected water snails. To determine the occurrence of cercariae-emitting snails in SchleswigHolstein, 155 public bathing places were visited and searched for fresh water snails. Family and genus of the collected snails were determined and the snails were examined for the shedding of cercariae, using a standard method and a newly developed method.
Objective: To generate preliminary information about of enteroviruses and Enterovirus 71 (EV71) in patients with aseptic meningitis in Khartoum State, Sudan.
Method: Cerebrospinal fluid specimens were collected from 89 aseptic meningitis patients from different Khartoum Hospitals
(Mohammed Alamin Hamid Hospital, Soba Teaching Hospital, Omdurman Military Hospital, Alban Gadeed Teaching Hospital and Police Hospital) within February to May 2015. Among these 89 patients, 43 (48%) were males and 46 (52%) were females. The patient’s age ranged between 1 day and 30 years old. The collected specimens were assayed to detect enteroviruses and EV71 RNA using Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) technique
Femoral hernias, comprise 2% to 4% of all hernias in the inguinal region, and occur most commonly in women. Th ey present typically with a mass below the level of the inguinal ligament. The sac may contain preperitoneal fat, omentum, small bowel, or other structures and have a high rate of incarceration and strangulation due to the small size of the hernia neck orifice, requiring emergency surgery. We present the case of a 54-year-old female patient with intestinal occlusion due to incarcerated femoral hernia, repaired by laparoscopic approach, that gave the patient the opportunity to attend her daughter’s wedding the same day.
Small Supernumerary Marker Chromosome (sSMC) is a rare genetic condition marked by the presence of an extra chromosome to the 46 human chromosomes. This case report describes a 4 year old child with SSMC on the 46th chromosome. The child presented with delayed speech and language development, seizures and mild developmental delay. Speech and Language evaluation was carried out and management options are discussed.
A catheter is a thin tube made from medical grade materials that serve a broad range of functions, but mainly catheters are medical devices that can be inserted in the body to treat disease or perform surgical procedures. Catheters have been inserted into body cavities, ducts, or vessels to allow for drainage, administration of therapeutic fluids or gases, operational access for surgery. Catheters help perform tasks in various systems such as cardiovascular, urological, gastrointestinal, neurovascular, and ophthalmic systems. A dataset of 12 patients with varying “weights” and “heights” was recorded along with the lengths of their catheter tubes. This data set was found from two revered statistical textbooks on linear regression and the Department of Scientific Computing at Florida State University. This data set was not able to be linked to any particular clinical or experimental research studies, but the data set can be used to help catheter manufacturers and medical professionals better decide on what particular catheter lengths to use for patients knowing only their height & weight. These research insights could be helpful to healthcare professionals that have patients with incomplete or no healthcare records
to decide what catheter length to use. The main investigative inquiry that needed to be answered was how does patient weight & height influence catheter length together and separately? We conducted linear regression and other statistical analysis procedures in R program & Microsoft Excel and discovered that this data exhibited a quality called multi collinearity. With multi collinearity, all predictors (2 or more
independent variables) are not significant in an all encompassing linear aggression, but the predictors might be significant in their own individual linear regressions. Individual linear regression analyses were conducted for both patient height & weight to see how much they both contribute to varying catheter length. Patient weight was found to be more impatful than patient height in relationship to catheter length, even though height and weight are a classical example of multi collinearity predictors.
Bovine mastitis has a negative impact through economic losses in the dairy sector across the globe. A cross sectional study was carried out from September 2015 to July 2016 to determine the prevalence of bovine mastitis, associated risk factors and isolation of major causative bacteria in lactating dairy cows in selected districts of central highland of Ethiopia. A total of 304 lactating cows selected randomly from five districts were screened by California Mastitis Test (CMT) for subclinical mastitis. Based on CMT result and clinical examination, over all prevalence of mastitis at cow level was 70.62% (214/304).
Two hundred fourteen milk samples collected from CMT positive cows were cultured for isolation of major causative bacteria. From 214 milk samples,187 were culture positive and the most prevalent isolates were Staphylococcus aureus 42.25% (79/187) followed by Streptococcus agalactiae 14.43%
(27/187). Other bacterial isolates were included Coagulase Negative Staphylococcus species 12.83% (24/187), Streptococcus dysgalactiae 5.88% (11/187), Escherichia coli 13.38% (25/187) and Entrococcus feacalis 11.23% (21/187) were also isolated. Moreover, age, parity number, visible teat abnormalities,husbandry practice, barn fl oor status and milking hygiene were considered as risk factors for the occurrence of bovine mastitis and they were found significantly associated with the occurrence of mastitis (p < 0.05). The findings of this study warrants the need for strategic approach including dairy extension that focus on enhancing dairy farmers’ awareness and practice of hygienic milking, regular screening for subclinical mastitis, dry cow therapy and culling of chronically infected cows.
A 36-year-old female developed right upper quadrant pain and nausea after taking the herbal supplement kratom for two weeks to manage back pain. Laboratory tests showed elevated liver enzymes. A liver biopsy ruled out other causes and determined she had drug-induced liver injury from kratom use. Her symptoms and liver enzymes gradually returned to normal over six weeks after stopping kratom. The case report discusses kratom's potential for hepatotoxicity and advises clinicians to consider its effects on patient health.
The assessment, diagnosis and treatment of critically ill patients is extremely challenging. Patients often deteriorate whilst being
reviewed and their rapidly changing pathophysiology barrages healthcare professionals with new data. Furthermore, comprehensive assessments must be postponed until the patient has been stabilised. So, important data and interventions are often missed in the heat of the moment. In emergency situations, suboptimal management decisions may cause signifi cant morbidity and mortality. Fortunately, standardisation and careful design of documentation (i.e. proformas and checklists) can enhance patient safety. So, I have developed a series of checklist proformas to guide the assessment of critically ill patients. These proformas also promote the systematic recording and presentation of information to facilitate the retrieval of the precise data required for the management for critically ill patients. The proformas have been modifi ed extensively over the last twenty years based on my personal experience and extensive consultation with colleagues in several world-renowned centres of excellence. The proformas were originally developed for use in the intensive therapy unit
or high dependency unit. However, they have been adapted for use by outreach teams reviewing patients admitted outside of critical care areas. The use of these tools can direct eff orts to provide appropriate organ support and provides a framework for diagnostic reasoning.
This review article discusses microvascular and macrovascular disease in systemic hypertension. It summarizes that:
1) Cardiac imaging plays a crucial role in risk stratifying hypertensive patients and identifying management strategies by properly diagnosing microvascular and coronary artery disease.
2) The nitric oxide synthase (eNOS) G298 gene allele may be a marker for microvascular angina in hypertensive patients, as studies have found it to be more prevalent in hypertensive patients with chest pain and reversible myocardial defects but normal coronary arteries.
3) Both structural changes like capillary rarefaction and functional changes like endothelial dysfunction can cause microvascular dysfunction and angina in hypertensive individuals in the absence of
This study characterized dengue infections in Pakistan by analyzing hematological and serological markers in 154 suspected dengue cases and 146 control patients with other febrile illnesses. NS1 antigen was detected in 55% of dengue cases, IgM antibodies in 30%, and both in 15%. Control groups primarily had malaria (71%) and enteric fever (20%). Hematological markers (platelet count, hematocrit, WBC) measured before and after treatment showed significant differences for platelet count and hematocrit but not WBC count between the groups. Analysis of clinical symptoms and serological/hematological markers helps diagnose dengue, assess prognosis, and inform prevention efforts to reduce morbidity, mortality and spread of the disease.
Researchers from Utrecht recently published yet another paper on the use of Magnetic Resonance Imaging (MRI)demonstrating an additional failed attempt to understand the importance of qualitative versus quantitative imaging, and anatomic versus physiologic imaging. Th e implications of this failure here cannot be overstated.
Introduction: Stroke is an even more dramatic major public health problem in young people. Goal of the study: Contribute to the knowledge of strokes in young people. Methodology: This was a retrospective study carried out over a period of 02 years (January 2017 to December 2018) including the files of patients aged 18 to 49 years hospitalized for any suspected case of stroke in the Neurology department of the University Hospital
Center of the Sino-Central African Friendship (CHUSCA) of Bangui.
Background: This report describes a unique case of a patient that developed psychotic symptoms believed to be secondary
to a tentorial meningioma with associated hydrocephalus. These psychotic symptoms subsequently abated with placement of a
ventriculoperitoneal shunt. Case description: 60-year-old female was admitted to an inpatient psychiatric facility on a psychiatric involuntary commitment petition due to progressive paranoia, homicidal ideation and psychosis. The work up showed a calcified six cm tentorial meningioma with associated hydrocephalus. The patient initially rejected treatment but later became amenable to placement of Ventriculoperitoneal Shunt
(VPS).
More from SciRes Literature LLC. | Open Access Journals (20)
Computer in pharmaceutical research and development-Mpharm(Pharmaceutics)MuskanShingari
Statistics- Statistics is the science of collecting, organizing, presenting, analyzing and interpreting numerical data to assist in making more effective decisions.
A statistics is a measure which is used to estimate the population parameter
Parameters-It is used to describe the properties of an entire population.
Examples-Measures of central tendency Dispersion, Variance, Standard Deviation (SD), Absolute Error, Mean Absolute Error (MAE), Eigen Value
Travel Clinic Cardiff: Health Advice for International TravelersNX Healthcare
Travel Clinic Cardiff offers comprehensive travel health services, including vaccinations, travel advice, and preventive care for international travelers. Our expert team ensures you are well-prepared and protected for your journey, providing personalized consultations tailored to your destination. Conveniently located in Cardiff, we help you travel with confidence and peace of mind. Visit us: www.nxhealthcare.co.uk
Nano-gold for Cancer Therapy chemistry investigatory projectSIVAVINAYAKPK
chemistry investigatory project
The development of nanogold-based cancer therapy could revolutionize oncology by providing a more targeted, less invasive treatment option. This project contributes to the growing body of research aimed at harnessing nanotechnology for medical applications, paving the way for future clinical trials and potential commercial applications.
Cancer remains one of the leading causes of death worldwide, prompting the need for innovative treatment methods. Nanotechnology offers promising new approaches, including the use of gold nanoparticles (nanogold) for targeted cancer therapy. Nanogold particles possess unique physical and chemical properties that make them suitable for drug delivery, imaging, and photothermal therapy.
5-hydroxytryptamine or 5-HT or Serotonin is a neurotransmitter that serves a range of roles in the human body. It is sometimes referred to as the happy chemical since it promotes overall well-being and happiness.
It is mostly found in the brain, intestines, and blood platelets.
5-HT is utilised to transport messages between nerve cells, is known to be involved in smooth muscle contraction, and adds to overall well-being and pleasure, among other benefits. 5-HT regulates the body's sleep-wake cycles and internal clock by acting as a precursor to melatonin.
It is hypothesised to regulate hunger, emotions, motor, cognitive, and autonomic processes.
Discover the benefits of homeopathic medicine for irregular periods with our guide on 5 common remedies. Learn how these natural treatments can help regulate menstrual cycles and improve overall menstrual health.
Visit Us: https://drdeepikashomeopathy.com/service/irregular-periods-treatment/
Breast cancer: Post menopausal endocrine therapyDr. Sumit KUMAR
Breast cancer in postmenopausal women with hormone receptor-positive (HR+) status is a common and complex condition that necessitates a multifaceted approach to management. HR+ breast cancer means that the cancer cells grow in response to hormones such as estrogen and progesterone. This subtype is prevalent among postmenopausal women and typically exhibits a more indolent course compared to other forms of breast cancer, which allows for a variety of treatment options.
Diagnosis and Staging
The diagnosis of HR+ breast cancer begins with clinical evaluation, imaging, and biopsy. Imaging modalities such as mammography, ultrasound, and MRI help in assessing the extent of the disease. Histopathological examination and immunohistochemical staining of the biopsy sample confirm the diagnosis and hormone receptor status by identifying the presence of estrogen receptors (ER) and progesterone receptors (PR) on the tumor cells.
Staging involves determining the size of the tumor (T), the involvement of regional lymph nodes (N), and the presence of distant metastasis (M). The American Joint Committee on Cancer (AJCC) staging system is commonly used. Accurate staging is critical as it guides treatment decisions.
Treatment Options
Endocrine Therapy
Endocrine therapy is the cornerstone of treatment for HR+ breast cancer in postmenopausal women. The primary goal is to reduce the levels of estrogen or block its effects on cancer cells. Commonly used agents include:
Selective Estrogen Receptor Modulators (SERMs): Tamoxifen is a SERM that binds to estrogen receptors, blocking estrogen from stimulating breast cancer cells. It is effective but may have side effects such as increased risk of endometrial cancer and thromboembolic events.
Aromatase Inhibitors (AIs): These drugs, including anastrozole, letrozole, and exemestane, lower estrogen levels by inhibiting the aromatase enzyme, which converts androgens to estrogen in peripheral tissues. AIs are generally preferred in postmenopausal women due to their efficacy and safety profile compared to tamoxifen.
Selective Estrogen Receptor Downregulators (SERDs): Fulvestrant is a SERD that degrades estrogen receptors and is used in cases where resistance to other endocrine therapies develops.
Combination Therapies
Combining endocrine therapy with other treatments enhances efficacy. Examples include:
Endocrine Therapy with CDK4/6 Inhibitors: Palbociclib, ribociclib, and abemaciclib are CDK4/6 inhibitors that, when combined with endocrine therapy, significantly improve progression-free survival in advanced HR+ breast cancer.
Endocrine Therapy with mTOR Inhibitors: Everolimus, an mTOR inhibitor, can be added to endocrine therapy for patients who have developed resistance to aromatase inhibitors.
Chemotherapy
Chemotherapy is generally reserved for patients with high-risk features, such as large tumor size, high-grade histology, or extensive lymph node involvement. Regimens often include anthracyclines and taxanes.
Osvaldo Bernardo Muchanga-GASTROINTESTINAL INFECTIONS AND GASTRITIS-2024.pdfOsvaldo Bernardo Muchanga
GASTROINTESTINAL INFECTIONS AND GASTRITIS
Osvaldo Bernardo Muchanga
Gastrointestinal Infections
GASTROINTESTINAL INFECTIONS result from the ingestion of pathogens that cause infections at the level of this tract, generally being transmitted by food, water and hands contaminated by microorganisms such as E. coli, Salmonella, Shigella, Vibrio cholerae, Campylobacter, Staphylococcus, Rotavirus among others that are generally contained in feces, thus configuring a FECAL-ORAL type of transmission.
Among the factors that lead to the occurrence of gastrointestinal infections are the hygienic and sanitary deficiencies that characterize our markets and other places where raw or cooked food is sold, poor environmental sanitation in communities, deficiencies in water treatment (or in the process of its plumbing), risky hygienic-sanitary habits (not washing hands after major and/or minor needs), among others.
These are generally consequences (signs and symptoms) resulting from gastrointestinal infections: diarrhea, vomiting, fever and malaise, among others.
The treatment consists of replacing lost liquids and electrolytes (drinking drinking water and other recommended liquids, including consumption of juicy fruits such as papayas, apples, pears, among others that contain water in their composition).
To prevent this, it is necessary to promote health education, improve the hygienic-sanitary conditions of markets and communities in general as a way of promoting, preserving and prolonging PUBLIC HEALTH.
Gastritis and Gastric Health
Gastric Health is one of the most relevant concerns in human health, with gastrointestinal infections being among the main illnesses that affect humans.
Among gastric problems, we have GASTRITIS AND GASTRIC ULCERS as the main public health problems. Gastritis and gastric ulcers normally result from inflammation and corrosion of the walls of the stomach (gastric mucosa) and are generally associated (caused) by the bacterium Helicobacter pylor, which, according to the literature, this bacterium settles on these walls (of the stomach) and starts to release urease that ends up altering the normal pH of the stomach (acid), which leads to inflammation and corrosion of the mucous membranes and consequent gastritis or ulcers, respectively.
In addition to bacterial infections, gastritis and gastric ulcers are associated with several factors, with emphasis on prolonged fasting, chemical substances including drugs, alcohol, foods with strong seasonings including chilli, which ends up causing inflammation of the stomach walls and/or corrosion. of the same, resulting in the appearance of wounds and consequent gastritis or ulcers, respectively.
Among patients with gastritis and/or ulcers, one of the dilemmas is associated with the foods to consume in order to minimize the sensation of pain and discomfort.
How to Control Your Asthma Tips by gokuldas hospital.Gokuldas Hospital
Respiratory issues like asthma are the most sensitive issue that is affecting millions worldwide. It hampers the daily activities leaving the body tired and breathless.
The key to a good grip on asthma is proper knowledge and management strategies. Understanding the patient-specific symptoms and carving out an effective treatment likewise is the best way to keep asthma under control.
Pictorial and detailed description of patellar instability with sign and symptoms and how to diagnose , what investigations you should go with and how to approach with treatment options . I have presented this slide in my 2nd year junior residency in orthopedics at LLRM medical college Meerut and got good reviews for it
After getting it read you will definitely understand the topic.
The biomechanics of running involves the study of the mechanical principles underlying running movements. It includes the analysis of the running gait cycle, which consists of the stance phase (foot contact to push-off) and the swing phase (foot lift-off to next contact). Key aspects include kinematics (joint angles and movements, stride length and frequency) and kinetics (forces involved in running, including ground reaction and muscle forces). Understanding these factors helps in improving running performance, optimizing technique, and preventing injuries.
- Video recording of this lecture in English language: https://youtu.be/Pt1nA32sdHQ
- Video recording of this lecture in Arabic language: https://youtu.be/uFdc9F0rlP0
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
PGx Analysis in VarSeq: A User’s PerspectiveGolden Helix
Since our release of the PGx capabilities in VarSeq, we’ve had a few months to gather some insights from various use cases. Some users approach PGx workflows by means of array genotyping or what seems to be a growing trend of adding the star allele calling to the existing NGS pipeline for whole genome data. Luckily, both approaches are supported with the VarSeq software platform. The genotyping method being used will also dictate what the scope of the tertiary analysis will be. For example, are your PGx reports a standalone pipeline or would your lab’s goal be to handle a dual-purpose workflow and report on PGx + Diagnostic findings.
The purpose of this webcast is to:
Discuss and demonstrate the approaches with array and NGS genotyping methods for star allele calling to prep for downstream analysis.
Following genotyping, explore alternative tertiary workflow concepts in VarSeq to handle PGx reporting.
Moreover, we will include insights users will need to consider when validating their PGx workflow for all possible star alleles and options you have for automating your PGx analysis for large number of samples. Please join us for a session dedicated to the application of star allele genotyping and subsequent PGx workflows in our VarSeq software.
NAVIGATING THE HORIZONS OF TIME LAPSE EMBRYO MONITORING.pdfRahul Sen
Time-lapse embryo monitoring is an advanced imaging technique used in IVF to continuously observe embryo development. It captures high-resolution images at regular intervals, allowing embryologists to select the most viable embryos for transfer based on detailed growth patterns. This technology enhances embryo selection, potentially increasing pregnancy success rates.
2. SCIRES Literature - Volume 3 Issue 1 - www.scireslit.com Page - 009
International Journal of Cardiovascular Diseases & Diagnosis
ABSTRACT
Introduction: Radiofrequency Ablation (RF) of Nodal Reentry Tachycardia (AVNRT) requires precision to avoid AV block. 3D Electro-Anatomic Mapping
(EAM) systems allowed to reduce radiological exposure. We sought to evaluate safety and efficacy of AVNRT ablation, analyzing tip stability with a EAM
system aiming a Minimal Fluoroscopic Approac (MFA).
Methods: Consecutive patients (pts) with AVNRT were submitted to ablation using an EAM system. Ablation was performed with a flexible-tip Irrigated
Catheter (IAC,) whose stability was quantified by the SD of the catheter coordinates in 3 axes of space (X,Y,Z)
Results: 50 pts with AVNRT were treated with RF (12 males, age 52,5 ± 16,6 years). The success rate was 100%, with a mean procedure time of 134
± 40 min, a mean fluoroscopy (fluo) time of 0,63 ± 1,97 sec and a very low mean fluo dosage (166 cGy/ cm2). In 44 pts (88%) no fluo was used. The mean
distance between RF and fast pathway was 14.9 ± 5.3 mm, while the average SD of the position of the ablation catheter during RF was 0.75 ± 0.50, 1.17 ±
0.78, 1.06 ± 0.54 mm respectively in the X-Y-Z axes, confirming a great stability of ablation catheter. After a mean FU of 12 ± 6,4 months 48 patients (96%)
showed no recurrence. No complications occurred.
Conclusion: The MFA using a IAC is a safe, cost-effective, feasible alternative to a manual approach for AVNRT ablation. EAM allowed for the first
time the analysis of the exact tip position in 3D-axes, ensuring adequate stability of ablation catheter, minimizing the fluo time and without compromising
success rates or safety.
Keywords: AVNRT; 3D mapping system; Irrigated tip catheter; Ablation; Zero X ray
INTRODUCTION AND PURPOSE OF THE
STUDY
Atrioventricular Nodal Re-Entrant Tachycardia (AVNRT) is
the most common Supraventricular Tachycardia (SVT) in adults,
accounting for approximately 70% of paroxysmal SVT [1,2].
Older studies reported initial success rates of catheter ablation of
the AV nodal slow pathway as high as 97% with 5% rate of recurrence
over 2 years [3].
On the other hand, prior series showed rates of complete AV
block requiring pacemaker implantation of 0.8-1.3% [3-5]. The
conventional approach to catheter ablation of AVNRT was described
more than 25 years ago and involves empiric Radiofrequency (RF)
ablation of the slow pathway site using fluoroscopic anatomical
landmarks and specific intra-cardiac electrograms. More recently,
alternative ablation strategies have been introduced including the use
of cryoablation, irrigated radiofrequency ablation, and 3D Electro-
Anatomic Mapping (EAM) with the aim of reducing procedural
complications and radiation exposure [6-9].
Fluoroscopy during RF ablation of SVT exposes patients and
operators to ionizing radiation.
The demand for reducing radiation exposure by optimizing
fluoroscopy or by the use of advanced technologies during these
procedures is particularly important, following the ALARA (as
low as reasonably achievable) principle and aiming the Minimal
Fluoroscopic Approach (MFA) [9-12].
It is well known that radiation increases the lifetime risk of
certain tumors, via stochastic and non-stochastic effects. The latent
period between radiation exposure and cancer presentation implies
that younger patients are more susceptible to this risk (because in
elderly patients this latent period is more likely to exceed the patient’s
life expectancy). Many patients undergoing SVT ablation are quite
young, and SVT ablation is common also in the paediatric population
[13].
Patients are at risk, but operators too; a growing evidence shows
that in physicians who perform fluoroscopic-guided procedures
radiation exposure is related to tumours of the brain and neck [14],
vascular disease[15], cognitive impairment [16].
Given these well-recognized hazards, it is very important to
develop and encourage zero- or near-zero-fluoroscopic approaches
in EP laboratory, in order to minimize such risks. These are especially
important in high-risk populations, including children, young people
and pregnant women. The benefits of using 3D EAM systems in the
EP lab have been documented in several recent reports [12,17]. The
advent of EAM allowed to reduce the radiological exposure and to
monitor the stability of the catheter during the procedure.
The purpose of the present study is to assess safety and efficacy
of ablation procedure for AVNRT and to evaluate the stability of
flexible-tip Irrigated Ablation Catheter (IAC) during procedure,
driven by an EAM system, aiming a zero or near-zero fluoroscopic
approach.
METHODS
Electrophysiology study
Informed written consent was obtained prior to all procedures.
Being a prospective study, all consecutive patients with SVT deemed
to perform AVNRT ablation were included without selection bias.
Diagnosis, procedural strategies, and treatment decisions were
specified by protocol. For all electrophysiology studies, vascular
access was obtained through both femoral veins and electrode
catheters were then advanced under electroanatomic mapping
guidance avoiding fluoroscopy from femoral veins to the target site.
The ablation procedure was performed using a FlexAbilityTM
- sensor-
enabledTM
(St Jude Medical/Abbott Inc) irrigated ablation catheter
with a 4 mm tip, with Ensite Precision (Abbott Inc) magnetic and
impedance-based 3D EAM system to create an electroanatomic
cardiac shell.
The procedure was guided by the EAM, allowing the measurement
of fast and slow pathway location. The AH intervals were measured
during pacing from different sites of Koch triangle, in order to mark
slow and fast pathway locations and identify the effective RF site.
IAC was used to obtain right atrium EAM, with particular concern in
Koch’s triangle. All sites with His Bundle potentials were annotated
with the EAM.
The ablation catheter was placed in the posteroseptal slow
pathway region. RF energy was applied to the lowest part of the Koch’s
triangle showing a local slow pathway electrogram (multiphasic atrial
component) and/or an A-V amplitude ratio from 1:4 to 1:2.
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At target sites, RF energy applications with IAC, ranging from
15W (close to the HIS Bundle) to 30w at 40°
C temperature, were
delivered. During RF, stability of the tip of ablation catheter was
analyzed and continuously checked in all 3 axes by evaluating the
mean distance from target site during RF delivery and the mean
distance from fast pathway.
Real-time position of the catheter tip was recorded and tracked
by the EAM.
Catheter stability during RF delivery was quantified by the
Standard Deviation (SD) of the catheter tip coordinates. The
presence of irritative junctional rhythm during RF delivery and
the corresponding catheter tip location were also recorded and
considered for stability analysis.
The presence of junctional beats during ablation was judged as
indicative of a correct ablation site. If no junctional beats occurred,
RF was stopped after 20-30 s and another site was checked If AVNRT
was still inducible, the ablation catheter was moved to more superior
sites without His bundle electrograms or near the ostium of coronary
sinus.
The endpoint of ablation was non-inducibility of AVNRT
without evidence of AV nodal slow pathway conduction (i.e. slow
pathway ablation) or jump with just only single nodal echo beat (i.e.,
slow pathway modulation) both at basal condition (programmed
stimulation protocol) and with isoproterenol infusion during
programmed stimulation protocol, with a waiting period after
ablation of at least 30 minutes.
Study endpoint and Clinical management
The primary study endpoint was ablation success (including
acute success until 7 days post-procedure and midterm success at
least 6 months after procedure or at the last available cardiologic visit
or clinic record), and catheter stability evaluation in 3 axes during
radiofrequency ablation.
Secondary study endpoints were safety profile (accounting major
and minor complications), procedure duration, total fluoroscopy
time and fluoroscopy dosage for the patients.
Patients attended cardiological visit at our ambulatory 2-3
months after procedure, 1 year after procedure and then every year.
A procedure was considered to be acutely successful if a previously
inducible arrhythmia was rendered non-inducible at the end of the
case or if there was elimination of dual AV nodal physiology in a
patient with a documented history of SVT that proved non-inducible
at the end of the procedure. Mid-term success was defined as no
documented recurrence of SVT based on the last available primary
care or cardiology clinic record.
Major complications were defined as death, stroke, vascular access
complications requiring surgical intervention or blood transfusion,
heart block requiring a permanent pacemaker, or pericardial effusion
requiring an intervention within thirty days of the procedure. Minor
complications were defined as transient AV block (without need of
permanent pacemaker) or hematoma requiring watchful observation
with at least 1 adjunctive day of hospitalization.
STATISTICAL ANALYSIS
Categorical variables were summarized by number and
percentage. Continuous variables were summarized as a mean and
standard deviation. This study was approved by the local ethics
committee affiliated with hospital Institution.
RESULTS
All patients were prospectively recruited at our Centre from
March 2017 to October 2018. Two operators performed the ablation
procedures: one is well experienced and the other one is in training.
The study included 50 consecutive patients with AVNRT,
targeted for ablation; 49 patients (98%) showed a typical slow-fast
AVNRT, 1 slow-slow AVNRT. No patients were excluded from our
study. The study included 2 pregnant women and both procedures
were performed without fluoroscopy, preserving their safety and
their babies’ one.
The average age was 52,5 ± 16,6 years, 12 patients (24%) were male,
4 (8%) showed a structural heart disease (1 ischemic cardiomyopathy,
2 idiopathic dilated cardiomyopathy, 1 with previous myocarditis)
of whom 3 showed a reduced ejection fraction < 50%. Before
ablation procedure, 8 patients (16%) took antiarrhythmic drugs (6
Beta blockers, 1 amiodarone, 1 calcium channel blockers). After
ablation procedure no patients took antiarrhymic drugs for the index
arrhythmia.
The average procedure time was 134 ± 40 min, the average RF
delivery time was 10,7 ± 7 minutes.
Of 50 patients treated, 44 (88%) underwent a complete zero-
fluoroscopic ablation procedure, and 6 patients (12%) were treated
with a low fluoroscopic dose of 1390 ± 852 cGy/cm2 with an average
fluoroscopy time of 5,3 ± 2,9 minutes (that is 317 ± 174 seconds) –
with mean data just considering 6 procedures.
Considering all 50 procedures, the average fluoroscopy time
of 0,63 ± 1,97 minutes (that is 38 ± 118 seconds) and an average
fluoroscopy dosage of 166 ± 531 cGy/cm2.
Both acute (peri-procedural) and mid-term AVNRT ablation
success was satisfactory: all 50 procedures (100%) were acutely
successful and 48 patients (96%) showed no recurrences after an
average follow-up of 12,0 ± 6,4 months. 2 patients (4%) after few
weeks unfortunately experienced the index arrhythmia recurrence
and required a new procedure. Considering the close proximity
between fast and slow pathway, in both cases a successful cryo-
ablation was performed due to the proximity of slow pathway to His
bundle.
Overall, no major complications occurred (0%), and just 1 patient
(2%) had a minor complication showing a transient AV high degree
block during ablation with a rapid recovery of sinus rhythm after
few minutes (pacemaker was not required). Clinical variables and
procedural characteristics are summarized in table 1.
Figure 1A and 1B show 3D EAM during ablation and real time
position of the catheter tip during RF delivery respectively. The mean
distance between successful RF application and fast pathway was 14,9
± 5.3mm standard deviation of the ablation catheter position during
RF, as a measure of catheter stability, was 0.75 ± 0.50, 1.17 ± 0.78, 1.06
± 0.54 mm respectively on x, y, z axes, confirming stability of catheter
and adequate distance from fast pathway (Figure 2).
It has also been noted that, even in conditions of similar
conduction times through slow and fast pathway (Δ < 30 ms), the SD
of the position has maintained, on average, very low values (in 91,3%
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International Journal of Cardiovascular Diseases & Diagnosis
RF application, < 2 mm), thus ensuring stability also in conditions
of potentially higher risk of AV block. Slow pathway ablation was
achieved in 40 patients (80%), whereas in the remaining patient’s
slow pathway modulation was performed.
The procedure was guided by EAM, allowing the measurement
of fast and slow pathway location. Catheters were placed by the aid of
the mapping system using one bipole on the coronary sinus catheter
as a reference. The geometry was created by the sensor-enabled
ablation catheter. The AH intervals were measured during pacing
from different sites of Koch triangle, in order to mark slow and fast
pathway locations and identify the effective RF site. To avoid damage,
the his region was tagged with yellow dots. The orange tag represents
the fast pathway, while green tag represents slow pathway region and
violet tag is the ablation site target (Figure 1A).
Catheter stability during RF delivery was quantified by the
Standard Deviation (SD) of the catheter tip coordinates. The
presence of irritative junctional rhythm during RF delivery and
the corresponding catheter tip location were also recorded and
considered for stability analysis (Figure 1B).
DISCUSSION
Our study showed 5 notable findings: 1-AVNRT ablation
without fluoroscopic or a MFA provided similar results compared
to traditional fluoroscopic approach. Our study reported a very low
fluoroscopic exposure, with high rate of acute (100%) and mid-term
success (96%) and no major complications.
According to international guidelines [2] patients with frequent
symptomatic episodes of AVNRT should strongly be offered the
option of catheter ablation, which is the gold standard treatment with
high rate of success (higher than 95-100%) with a recurrence of 4-5%
and very low rates of major complications [3,18-20].
In fact, other options such chronic antiarrhythmic therapies, are
ineffective and poorly tolerated, showing a failure rate in more than
70% of patients in a long 5 years follow up [21].
Our study reported a very low fluoroscopic exposure, with high
rate of acute (100%) and mid-term success (96%) and no major
complications (0%). Ultimately, our findings are comparable to
previous [3-5] and recent [9,11,20] studies reporting long-term
success rates of approximately 94-97% for ablation of typical AVNRT,
and very low major complication rates (0-1,2%) [11,20,22,23].
3D EAM with or without MFA showed non inferiority compared
to traditional procedure; many studies reported similar complication
rates for MFA (or EAM-alone) and traditional ablation strategies
[6,8,11,20,24].
In our study slow pathway ablation was achieved in the large
majority of patients. Currently, non-inducibility of AVNRT with and
without isoproterenol infusion in patients without residual evidence
of dual Atrioventricular Node (AVN) pathways such as AVN echoes
is considered as an acceptable endpoint for RF ablation. In Nikoo et
al study [25] the recurrence rate of AVNRT in patients with a non-
inducible AVNRT accompanied by postablation inducible single
AV echo beats over a wide echo zone is not higher than those with
resultant slow pathway elimination (no AVN echoes) or modification
with single AV echo beats over a narrow echo zone. This finding
Table 1: Clinical variables and procedural characteristics.
Clinical Variables
Number of patients 50
Average Age (years) 52,5 ± 16,6
Male 12 (24%)
Structural heart disease 4 (8%)
Antiarrhythmic drug use 8 (16%)
Typical slow-fast 49 (98%)
Procedural Characteristics
Mean fluoroscopy time (min) 0,63 ± 1,97
Procedures completely without fluoroscopy 44 (88%)
Procedural time (min) 134 ± 40
Acute procedural success 50 (100%)
Success at last Follow up 48 (96%)
Mean follow up (months) 12,0 ± 6,4
AV node permanent injury 0
HIS
fast
pathway
slow
pathway
Ablation
site
Figure 1A Figure 1 B
Figure 1A: Representative three dimensional electroanatomical map during
ablation for AVNRT in Left Anterior Oblique (LAO) projection of the right
atrium.
Figure 1B: LAO projection. Real-time position of the catheter tip was recorded
and tracked by the mapping system.
Figure 2: The figure shows the measure of catheter stability, with a mean
tridimentional standard deviation of 0.75 ± 0.50, 1.17 ± 0.78, 1.06 ± 0.54
mm on x, y, z axes respectively (x on red, y in green, z in violet). These data
confirm adequate stability of the tip during all RF which triggered junctional
rhythm/junctional tachycardia (in total 199 RF lesions were achieved in 50
patients).
The blue line indicates the mean distance from tip to fast pathway during
each RF target lesion. The mean distance between successful RF application
and fast pathway was 14,9 ± 5.3 mm.
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International Journal of Cardiovascular Diseases & Diagnosis
conforms with the results from other studies [20]and a meta-analysis
[26] indicating that further ablation in patients who have evidence of
dual AV node physiology but are non-inducible for AVNRT is not
routinely required.
2-A completely fluorless AVNRT ablation was achieved in the
great majority of patients (88%) with a great decrease in patients’ and
physicians’ exposure. It has been estimated that an interventional
cardiologists presents a median radiation exposure per year equivalent
to 250 chest X-rays (5 mSv)[12], and this has recently been related to
an increased risk of cognitive impairment and brain malignancy [14-
16]. Ionizing radiation is known to be teratogenic and carcinogenic;
the reduction in its use has been a focus for many years. The advent of
non-fluoroscopic technologies guarantees X-rays exposure reduction
for both patient and operator during catheter ablation procedure. The
useofaMFAwiththeEnSiteTM
NavXTM
navigationsystemisassociated
with a significant reduction in total fluoroscopy time without any
significant difference in terms of success and complication rates [27-
29]. In this regard, a recent Italian multicentre trial (NO PARTY)
[17]randomized 262 patients with SVTs to conventional approach or
the EnSiteTMNavX ™ navigation system with minimal fluoroscopy.
Zero-fluoroscopy was achieved in 72% of patients in the minimal
fluoroscopy group, with significant overall reduction of the radiation
dose. According to ALARA principle (As Low as Reasonably
Achievable), we reached a zero-fluoroscopy procedure in 88%
(Figure 3). Just few cases (6/50 patients, 12%) required low dose of
fluoroscopy, mainly due to 3 reasons: electro-anatomic abnormality
of Koch triangle (3 cases), a very difficult femoral vascular access
(2 patients), procedure performed with a subclavian access only (1
patient). In cases with variations in anatomy (a.e. kinking of the
vessels, wide coronary sinus ostia) it can be impossible to get the
catheters in place or the ablation side cannot easily be found with
electro anatomy information alone. Here fluoroscopy together with
the electro anatomic information still plays an unreplaceable role.
Nevertheless reducing fluoroscopy time is important and necessary
due to increasing procedure numbers. The results in our study
are consistent with those exposed in the Magma study [11], which
compared manual traditional catheter ablation to remote magnetic
navigation. Our research showed very low fluoroscopy time (mean
time of 38 sec that is 0,63 minutes) and very low fluoroscopic dosage
(166 cGy/cm2), even lower than those reported in the Magma study
(respectively 6 min and 425 cGy/cm2). Otherwise our study revealed
longer procedure times (134 minutes) compared to MAGMA study
(88 minutes) [11] but shorter procedures times compared to the
study of Chrispin, et al (154-181 min) [20].
3-To our knowledge, this is the first study reporting a three
dimensional analysis about stability of the catheter tip during RF
delivery. Our results showed a great stability of ablation catheter: the
stable tip position with an average motion of about 1 mm in all 3 axes
ensured high precision and an adequate distance between ablation
target zone and fast pathway (14,9mm). Furthermore, 3D EAM
allowed a continuous point-by-point testing of tip stability during RF,
ensuring a continuous check of the catheter position and tip stability
also in conditions of higher risk of AV block.
We can postulate that the advantage of MFA, is the ability to
specifically mark the exact anatomical location of the His bundle
to avoid radiofrequency delivery in His bundle proximity, thereby
potentially reducing the frightening risk of iatrogenic AV block.
Chrispins, et al [20] showed that the use of modern technologies
such irrigated radiofrequency ablation catheters and 3D EAM were
not associated with long-term success rates or complications. In
absence of a direct comparison about this specific issue, we believe
that this one could be an opportunity for further investigations. In
manual ablation, it is often harder to achieve stability in this region
due to significant wall motion. 3D EAM allows to check second-to-
second and pont-by-point stability of the tip. Experienced clinicians
utilize various methods to achieve stability at the AV junction
during manual ablation including fine tactile feedback, use of long
sheaths and continuous fluoroscopy. However, for the reasons just
mentioned, EAM without the need for continuous fluoroscopy, could
be safer.
4-Even in relatively difficult or small anatomies (short distance
between fast and slow pathway) and without fluoroscopic guidance,
the use of IAC ensures adequate stability and optimal conditions for
mapping and ablation of the slow pathway. The magnetic navigation
system can really facilitate during mapping and ablation with up
to one-millimetre precision. The length of Koch’s triangle has been
shown to be approximately 18 mm (distance from the CS Os to His)
[30].
The compact AV node which is of 5-7 mm length is located in
the upper segment of the Koch’s triangle and the His bundle at its
apex [31].
In 25% of patients the His bundle could be located within 5 mm of
CS upper lip [30]. Significant variability exists in the relative location
of the His bundle with respect to the slow pathway [32],hence precise
three-dimensional mapping of the His bundle in relation to potential
ablations target is of great importance. In some studies, the location
of the successful site of ablation was very variable, ranging from 25
mm from the lowest His position [32]to less than 10 mm[33].
There is not a standard in RF ablation of AVNRT; with a 4mm tip
ablation catheter the modulation of the slow pathway of the AV node
with 30 and 50 W both have very high short- and long-term success
rates with low risks of adverse events.
Modern tools including 3D EAM and irrigated catheters –
whose use is increasing [20]- are not associated with a decrease in
complication rate or improvement in long-term success [6,8].
RF ablation was performed with a 4mm IAC, with a 1-4-1 mm
spacing and 1 mm band electrodes which enhance EGM signals
and reduce far-field sensing. In animal models this catheter reduced
overall procedural risk with lower incidence of steam pops compared
to ThermoCool SF, and lower incidence of charring and coagulum
formation in a beating heart [34].
Figure 3: Fluoroscopic time (blue dots) for every procedure performed, with a
progressive trend in decreasing fluoroscopic exposure (blue line). According
to ALARA principle we reached a zero-fluoroscopy procedure in 88%. Just 6
patients (12%) required low dose of fluoroscopy.
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Thestudy[33]showedthatFlexAbilitycatheterissafeandeffective
with average atrial lesions with a superficial diameter of 7,5 ± 2,4 mm
and 4,2 ± 2,9 in depth at 35 W, without significant difference in lesion
sizes compared to both standard ThermoCool and ThermoCool SF.
5-This experience on a cohort of adults confirms feasibility
and cost-effectiveness of AVNRT ablation with MFA. A cost-
effectiveness analysis was also performed in No-PARTY study [17],
with a recommendation on acceptable extra-costs in the same series.
Moreover, compared to conventional approach, in NO Party trial in
MFA the decrease in patients’ exposure shows a 96% reduction in the
estimated risks of cancer incidence and mortality, with an important
reduction in estimated years of life lost and years of life affected. At a
rough economical analysis, the increase in life expectancy and in the
period of cancer-free life makes the MFA economically affordable in
most European countries (NO PARTY) [17].
Regarding economic considerations about the minimally
fluoroscopic approach, there are no studies providing a cost-
effectiveness analysis. Data deriving from NO PARTY study show
that the extra cost related to the EAM can be considered economically
affordable.
LIMITATIONS
Our study has some limitations. This is a single-center study
(with 2 operators), it is not randomized because all patients were
prospectivelyrecruitedtoMFA,andwithalimitednumberofpatients.
Moreover, it was therefore not intended to establish comparative
safety and efficacy for widespread applicability. A randomized control
trial would be needed to determine safety and efficacy in comparison
to traditional fluoroscopic approach.
CONCLUSION
This experience demonstrates the feasibility, safety and
acute efficacy of ablation treatment driven by a EAM in patients
with AVNRT. Even in relatively difficult anatomies and without
fluoroscopy, the use of this catheter ensured adequate stability for
mapping and ablation of the slow pathway. MFA showed optimal
acute and midterm success without complications, with similar results
compared to traditional approach but with a mean very low negligible
dose exposition, enabling the physicians to check continuously the
stability of the tip and allowing the great majority of procedures to be
performed without fluoroscopy.
For the first time the analysis of the exact tip position in 3D-axes
was performed using an EAM system, ensuring a greater safety of
ablation procedure, minimizing radiation exposure time and without
compromising success rates or safety.
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