The document summarizes a study examining the effects of epinephrine and norepinephrine on the arterial pulse wave in normotensive subjects. Epinephrine increases cardiac output and decreases peripheral resistance, while norepinephrine increases peripheral resistance with little effect on cardiac output. The study found that epinephrine diminished or eliminated the dicrotic wave, while norepinephrine had less effect, suggesting the dicrotic wave originates from peripheral factors in addition to aortic valve closure.
This document discusses cardiac resynchronization therapy (CRT) for heart failure patients. Some key points:
- CRT improves symptoms, exercise tolerance, quality of life and reduces mortality for selected heart failure patients.
- Non-response to CRT remains a problem, occurring in 30-45% of patients.
- Patient selection factors like QRS duration, bundle branch block pattern and degree of ventricular dyssynchrony impact response.
- Optimal lead placement and device programming are important for response. Follow-up optimization of atrioventricular and interventricular delays can improve outcomes.
This study analyzed data from the MADIT-CRT trial to assess the relationship between left ventricular remodeling patterns, as measured by relative wall thickness (RWT), and the risk of ventricular arrhythmias in patients with left ventricular dysfunction. The study found that lower RWT, indicating more eccentric hypertrophy, was associated with a higher risk of ventricular arrhythmias. Additionally, greater increases in RWT from baseline to one year with CRT-D therapy were related to lower risks of future arrhythmia events. RWT was found to be the best echocardiographic predictor of arrhythmias compared to other commonly used measures. This study provides evidence that RWT can help predict arrhythmia risk and the benefits of
1) The document discusses various cases involving cardiac resynchronization therapy (CRT) implantation and troubleshooting.
2) Techniques described include accessing the coronary sinus using guidewires when dissection occurs and using a steerable catheter to engage alternative cardiac veins.
3) Optimizing outcomes involves addressing issues like phrenic nerve stimulation, adjusting atrioventricular delays, and replacing unstable leads over time.
This document discusses troubleshooting of implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy (CRT). It describes evaluating patients who receive shocks from their ICD and assessing ineffective or absent treatment. The document outlines different causes of oversensing that can lead to inappropriate shocks, such as P-wave oversensing, R-wave double counting, and T-wave oversensing. It provides guidance on approaches to reduce oversensing, including adjusting sensitivity thresholds and blanking periods. The document emphasizes that identifying and addressing lead failures is important for preventing repetitive inappropriate shocks.
1) The ECG can be used both before and after cardiac resynchronization therapy (CRT) to select appropriate patients and optimize device programming.
2) Pre-CRT, the ECG helps identify ventricular dyssynchrony and predict response. A wide QRS duration is necessary but not sufficient for a positive response.
3) Post-CRT, the ECG confirms biventricular capture and can predict reverse remodeling based on the degree of QRS narrowing achieved. Optimizing programming using ECG criteria may improve outcomes.
This document contains an ECG report from the Department of Cardiology at JIPMER in Pondicherry, India. It describes the ECG findings of a patient who presented with narrow complex tachycardia and includes the results of an electrophysiological study and ablation. The EPS found the patient had atrial tachycardia originating from the left atrium posteriorly, and they underwent successful ablation. The document provides details of the case from initial ECG and symptoms to diagnosis and treatment.
The document discusses using noncontact mapping (NCM) to characterize the origin of focal atrial tachycardia (AT). NCM uses a multielectrode array to map cardiac activation across the entire atrium. Studies have found that focal AT typically originates from areas of low voltage surrounding scar zones. The origin site shows centrifugal activation spread and a sharp unipolar electrogram. Adenosine can terminate focal AT by shifting the origin location or decreasing electrogram voltages. Catheter ablation targeting the origin site or nearby areas of slow conduction is effective for eliminating focal AT.
This document summarizes the results of the CARE-HF trial, which investigated the effects of cardiac resynchronization therapy (CRT) in patients with heart failure. The trial found that CRT significantly reduced the risks of death and hospitalization compared to medical therapy alone. For every 9 patients treated with CRT, 1 death and 3 hospitalizations were prevented. The results provide strong evidence that CRT can improve outcomes for appropriately selected heart failure patients.
This document discusses cardiac resynchronization therapy (CRT) for heart failure patients. Some key points:
- CRT improves symptoms, exercise tolerance, quality of life and reduces mortality for selected heart failure patients.
- Non-response to CRT remains a problem, occurring in 30-45% of patients.
- Patient selection factors like QRS duration, bundle branch block pattern and degree of ventricular dyssynchrony impact response.
- Optimal lead placement and device programming are important for response. Follow-up optimization of atrioventricular and interventricular delays can improve outcomes.
This study analyzed data from the MADIT-CRT trial to assess the relationship between left ventricular remodeling patterns, as measured by relative wall thickness (RWT), and the risk of ventricular arrhythmias in patients with left ventricular dysfunction. The study found that lower RWT, indicating more eccentric hypertrophy, was associated with a higher risk of ventricular arrhythmias. Additionally, greater increases in RWT from baseline to one year with CRT-D therapy were related to lower risks of future arrhythmia events. RWT was found to be the best echocardiographic predictor of arrhythmias compared to other commonly used measures. This study provides evidence that RWT can help predict arrhythmia risk and the benefits of
1) The document discusses various cases involving cardiac resynchronization therapy (CRT) implantation and troubleshooting.
2) Techniques described include accessing the coronary sinus using guidewires when dissection occurs and using a steerable catheter to engage alternative cardiac veins.
3) Optimizing outcomes involves addressing issues like phrenic nerve stimulation, adjusting atrioventricular delays, and replacing unstable leads over time.
This document discusses troubleshooting of implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy (CRT). It describes evaluating patients who receive shocks from their ICD and assessing ineffective or absent treatment. The document outlines different causes of oversensing that can lead to inappropriate shocks, such as P-wave oversensing, R-wave double counting, and T-wave oversensing. It provides guidance on approaches to reduce oversensing, including adjusting sensitivity thresholds and blanking periods. The document emphasizes that identifying and addressing lead failures is important for preventing repetitive inappropriate shocks.
1) The ECG can be used both before and after cardiac resynchronization therapy (CRT) to select appropriate patients and optimize device programming.
2) Pre-CRT, the ECG helps identify ventricular dyssynchrony and predict response. A wide QRS duration is necessary but not sufficient for a positive response.
3) Post-CRT, the ECG confirms biventricular capture and can predict reverse remodeling based on the degree of QRS narrowing achieved. Optimizing programming using ECG criteria may improve outcomes.
This document contains an ECG report from the Department of Cardiology at JIPMER in Pondicherry, India. It describes the ECG findings of a patient who presented with narrow complex tachycardia and includes the results of an electrophysiological study and ablation. The EPS found the patient had atrial tachycardia originating from the left atrium posteriorly, and they underwent successful ablation. The document provides details of the case from initial ECG and symptoms to diagnosis and treatment.
The document discusses using noncontact mapping (NCM) to characterize the origin of focal atrial tachycardia (AT). NCM uses a multielectrode array to map cardiac activation across the entire atrium. Studies have found that focal AT typically originates from areas of low voltage surrounding scar zones. The origin site shows centrifugal activation spread and a sharp unipolar electrogram. Adenosine can terminate focal AT by shifting the origin location or decreasing electrogram voltages. Catheter ablation targeting the origin site or nearby areas of slow conduction is effective for eliminating focal AT.
This document summarizes the results of the CARE-HF trial, which investigated the effects of cardiac resynchronization therapy (CRT) in patients with heart failure. The trial found that CRT significantly reduced the risks of death and hospitalization compared to medical therapy alone. For every 9 patients treated with CRT, 1 death and 3 hospitalizations were prevented. The results provide strong evidence that CRT can improve outcomes for appropriately selected heart failure patients.
This document provides information on cardiac resynchronization therapy (CRT) including indications, benefits, types of cardiac dyssynchrony, assessment techniques, and optimization. Some key points:
- CRT improves outcomes for heart failure patients through improvements in LV function, reverse remodeling, and reduction in mitral regurgitation.
- Three main types of cardiac dyssynchrony are assessed: atrioventricular, interventricular, and intraventricular. Echocardiography techniques like tissue Doppler imaging are used to measure dyssynchrony.
- CRT works by resynchronizing ventricular contraction to improve filling, coordination, and contractility. Optimization techniques aim to maximize biventricular pacing
Pacemaker Mediated Tachycardia... or not?Junhao Koh
This patient has a history of heart failure and was admitted for worsening symptoms. She has a cardiac resynchronization therapy defibrillator (CRT-D) implanted but continues to have episodes of nonsustained ventricular tachycardia. Device interrogation revealed a mechanism of pacemaker-mediated tachycardia involving retrograde conduction of premature ventricular complexes triggering the device to pace the atria, initiating a reentrant loop. Changing the device settings eliminated this tachycardia.
This document provides an overview of cardiac resynchronization therapy (CRT), including indications, assessment of dyssynchrony, rationale/mechanism, trials, procedures, and programming. It discusses the types and assessment of cardiac dyssynchrony using ECG, echocardiography, MRI, and nuclear imaging. Key trials on CRT are summarized, showing benefits for heart failure patients with reduced ejection fraction and wide QRS duration or echocardiographic evidence of dyssynchrony even in narrow QRS.
Early repolarization (ER), consisting of a J-point elevation, notching or slurring of the terminal portion of the R wave (J wave), and tall/symmetric T wave, is a common finding on the 12-lead electrocardiogram. For decades, it has been considered as benign, barring sporadic case reports and basic electrophysiology research that suggested a critical role of the J wave in the pathogenesis of idiopathic ventricular fibrillation (VF). In 2007-2008, a high prevalence of ER in patients with idiopathic VF was reported and subsequent studies reinforced the results. This PPT describes the current state of knowledge concerning ER syndrome associated with sudden cardiac death.
The document discusses assessment of mechanical dyssynchrony for cardiac resynchronization therapy. It defines electrical and mechanical dyssynchrony, and describes the deleterious hemodynamic effects of left ventricular dyssynchrony. It then summarizes various echocardiographic tools for assessing atrioventricular dyssynchrony, interventricular dyssynchrony, and intraventricular dyssynchrony, including M-mode, tissue Doppler imaging, and three-dimensional echocardiography. Measurement techniques for different dyssynchrony parameters such as septal-posterior wall motion delay, lateral wall postsystolic displacement, and time to peak systolic velocity are outlined.
The document discusses several different cardiac conditions and test results including atrial fibrillation with complete heart block, second degree 2:1 heart block, complete heart block, atrial flutter with 2:1 block, amyloidosis indicated by an echocardiogram showing severe LVH, speckled appearance and low voltage limb leads on ECG, inferolateral reversible ischemia of moderate degree found on a graft study for a post-CABG patient which also showed an occluded superior OM and diseased OM2 and OM3 that were stented.
This document discusses the role of echocardiography in cardiac resynchronization therapy (CRT). It covers:
1) Using echocardiography pre-CRT implantation to evaluate dyssynchrony and predict response to CRT. Greater dyssynchrony indicates higher likelihood of response.
2) Using echocardiography post-CRT implantation to optimize device settings like atrioventricular delay and interventricular delay to maximize benefits. Methods like measuring aortic velocity time integral are used.
3) A hospital's experience with timing follow-up echocardiography post-implantation and optimization at baseline, 3 months, and every 6 months or as needed. Results showed CRT improved
1) This document discusses patient selection for cardiac resynchronization therapy (CRT). It covers the historical aspects and physiology of ventricular dyssynchrony as well as the role and importance of assessing dyssynchrony for patient selection.
2) Various echocardiography techniques for assessing mechanical dyssynchrony are described, including tissue Doppler imaging (TDI), speckle tracking, and 3D echocardiography. Major randomized controlled trials on CRT are also summarized.
3) While echocardiography is commonly used, the document notes that no single measure of dyssynchrony is recommended due to variability in results. Larger trials found CRT beneficial primarily in patients with prolonged QRS
Cardiac Resynchronization Therapy and ICDsAhmed Mahmood
Cardiac resynchronization therapy (CRT) uses an implanted device to resynchronize heart ventricle contractions, improving heart pumping efficiency. CRT-Ds additionally treat abnormal heart rhythms. CRT benefits include improved hemodynamics, reduced heart remodeling, and reduced hospitalizations and mortality. CRT is indicated for patients with left ventricular dysfunction, heart failure symptoms, and prolonged QRS duration, especially over 150ms with left bundle branch block. Randomized trials show CRT effectiveness includes these benefits compared to conventional therapy.
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.
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 routine follow-up procedures for patients with cardiac resynchronization therapy (CRT) devices. It recommends using the PBL-STOP method to review the patient's presenting rhythm, battery status, lead status, sensing, thresholds, and observations from the device. The device can provide 14 months of trended data on arrhythmias, activity levels, and fluid status that should be compared to the patient's reported symptoms. The trends can help assess issues like atrial fibrillation, heart rate variability, day and night heart rates, activity levels, fluid buildup, and how much pacing is received. The trend information should be evaluated to see if it matches any signs of worsening heart failure.
This document contains 16 medical cases involving electrocardiogram (ECG) readings and interpretations. Each case provides an ECG image and description of a patient's symptoms or medical history, and asks the reader to identify the diagnosis or next step. The document also includes explanations of various ECG patterns and conditions, such as R on T phenomenon, hyperkalemia, Brugada syndrome, lead reversals, and long QT interval with T-wave alternans. The goal is to teach readers how to properly analyze ECGs and apply that analysis to diagnosing cardiac conditions.
The document discusses sensing in implantable cardioverter defibrillators (ICDs). Reliable sensing of ventricular signals is crucial for ICDs to detect arrhythmias but oversensing can cause inappropriate shocks. While auto-adjusting algorithms generally work, oversensing of T-waves, lead fractures, electromagnetic interference or low R-wave amplitudes can still cause issues. Programming adjustments like sensitivity changes may help but must not compromise ventricular fibrillation detection.
This document contains an ECG quiz that tests the reader's ability to interpret electrocardiograms and diagnose cardiac conditions. It includes 10 multiple choice questions about various ECG readings showing conditions like acute myocardial infarction in different areas of the heart, pericarditis, effects of thrombolysis, and more. The questions aim to evaluate the reader's skill in locating areas of injury, categorizing vessel disease, differentiating disease mimics, and assessing risk of heart block.
This document discusses strategies to minimize right ventricular pacing, which can have deleterious effects. It summarizes several clinical trials that evaluated ventricular versus atrial or dual-chamber pacing. The trials generally found that atrial or dual-chamber pacing reduced atrial fibrillation compared to ventricular pacing, though effects on other outcomes like mortality were less clear. The document recommends that right ventricular pacing be avoided or minimized when possible, through use of AAI pacing, DDD pacing with long fixed AV delays, search AV hysteresis algorithms, or mode-switching algorithms that favor intrinsic conduction.
A 61-year-old man presented with chest pain and was found to have ST-segment elevation in multiple leads on his electrocardiogram (ECG), indicating a heart attack. Additional ECG views showed involvement of the right ventricle. Coronary angiography revealed a 100% blockage of the right coronary artery near the branch supplying the right ventricle. The blockage was opened with a percutaneous coronary intervention, restoring blood flow. The man's condition improved with treatment, and follow-up testing showed his left ventricle function was normal but there was mild dysfunction of the right ventricle.
This document discusses the history and evidence for cardiac resynchronization therapy (CRT). It notes that approximately 25% of heart failure patients have intraventricular conduction delays that cause dyssynchronous contraction. CRT aims to resynchronize contraction by pacing both ventricles simultaneously. Randomized controlled trials found CRT improves symptoms, exercise capacity, and survival in patients with low ejection fraction and wide QRS. Guidelines recommend CRT for class III/IV heart failure patients with LBBB morphology and QRS >120ms. Some evidence also supports benefit in milder heart failure. Response can vary and not all patients respond equally.
Today, in addition to measurement of left ventricular ejection fraction, the simple 12-lead surface ECG remains the only evidence-based means of identifying patients who may obtain the substantial benefits of CRT
This document discusses various types and assessment of left ventricular dyssynchrony. It defines electrical and mechanical dyssynchrony. It describes different types of dyssynchrony including atrioventricular, interventricular, and intraventricular dyssynchrony. It discusses various echocardiography techniques to demonstrate and quantify each type of dyssynchrony, including M-mode, tissue Doppler, speckle tracking, and 3D echocardiography. It also mentions the use of MRI to assess dyssynchrony. The key application of assessing dyssynchrony is to predict response to cardiac resynchronization therapy in patients with heart failure.
Hormonlar nöroendokrin sistem (yani sinir hücresi olarak bilinen nöronlar ve çeşitli salgı bezleri) tarafından yapılırlar. Hormonlar özellikle yüksek yapılı hayvanlarda sinyal iletimi, davranış ve enerji metabolizmasında önemli roller üstlenmişlerdir ve kanla hedef dokulara taşınırlar
Effects of Norepinephrine and Epinephrine on CardiomyocyteAldrin Corañez
The document describes the process of how epinephrine and norepinephrine trigger contraction of cardiac muscle cells. It involves:
1) The binding of epinephrine/norepinephrine to β-adrenergic receptors on cardiac cells, activating associated G proteins.
2) The G proteins activate adenylate cyclase, catalyzing the conversion of ATP to cyclic AMP (cAMP).
3) cAMP activates protein kinase A, which phosphorylates proteins involved in calcium ion movement and muscle contraction.
This document provides information on cardiac resynchronization therapy (CRT) including indications, benefits, types of cardiac dyssynchrony, assessment techniques, and optimization. Some key points:
- CRT improves outcomes for heart failure patients through improvements in LV function, reverse remodeling, and reduction in mitral regurgitation.
- Three main types of cardiac dyssynchrony are assessed: atrioventricular, interventricular, and intraventricular. Echocardiography techniques like tissue Doppler imaging are used to measure dyssynchrony.
- CRT works by resynchronizing ventricular contraction to improve filling, coordination, and contractility. Optimization techniques aim to maximize biventricular pacing
Pacemaker Mediated Tachycardia... or not?Junhao Koh
This patient has a history of heart failure and was admitted for worsening symptoms. She has a cardiac resynchronization therapy defibrillator (CRT-D) implanted but continues to have episodes of nonsustained ventricular tachycardia. Device interrogation revealed a mechanism of pacemaker-mediated tachycardia involving retrograde conduction of premature ventricular complexes triggering the device to pace the atria, initiating a reentrant loop. Changing the device settings eliminated this tachycardia.
This document provides an overview of cardiac resynchronization therapy (CRT), including indications, assessment of dyssynchrony, rationale/mechanism, trials, procedures, and programming. It discusses the types and assessment of cardiac dyssynchrony using ECG, echocardiography, MRI, and nuclear imaging. Key trials on CRT are summarized, showing benefits for heart failure patients with reduced ejection fraction and wide QRS duration or echocardiographic evidence of dyssynchrony even in narrow QRS.
Early repolarization (ER), consisting of a J-point elevation, notching or slurring of the terminal portion of the R wave (J wave), and tall/symmetric T wave, is a common finding on the 12-lead electrocardiogram. For decades, it has been considered as benign, barring sporadic case reports and basic electrophysiology research that suggested a critical role of the J wave in the pathogenesis of idiopathic ventricular fibrillation (VF). In 2007-2008, a high prevalence of ER in patients with idiopathic VF was reported and subsequent studies reinforced the results. This PPT describes the current state of knowledge concerning ER syndrome associated with sudden cardiac death.
The document discusses assessment of mechanical dyssynchrony for cardiac resynchronization therapy. It defines electrical and mechanical dyssynchrony, and describes the deleterious hemodynamic effects of left ventricular dyssynchrony. It then summarizes various echocardiographic tools for assessing atrioventricular dyssynchrony, interventricular dyssynchrony, and intraventricular dyssynchrony, including M-mode, tissue Doppler imaging, and three-dimensional echocardiography. Measurement techniques for different dyssynchrony parameters such as septal-posterior wall motion delay, lateral wall postsystolic displacement, and time to peak systolic velocity are outlined.
The document discusses several different cardiac conditions and test results including atrial fibrillation with complete heart block, second degree 2:1 heart block, complete heart block, atrial flutter with 2:1 block, amyloidosis indicated by an echocardiogram showing severe LVH, speckled appearance and low voltage limb leads on ECG, inferolateral reversible ischemia of moderate degree found on a graft study for a post-CABG patient which also showed an occluded superior OM and diseased OM2 and OM3 that were stented.
This document discusses the role of echocardiography in cardiac resynchronization therapy (CRT). It covers:
1) Using echocardiography pre-CRT implantation to evaluate dyssynchrony and predict response to CRT. Greater dyssynchrony indicates higher likelihood of response.
2) Using echocardiography post-CRT implantation to optimize device settings like atrioventricular delay and interventricular delay to maximize benefits. Methods like measuring aortic velocity time integral are used.
3) A hospital's experience with timing follow-up echocardiography post-implantation and optimization at baseline, 3 months, and every 6 months or as needed. Results showed CRT improved
1) This document discusses patient selection for cardiac resynchronization therapy (CRT). It covers the historical aspects and physiology of ventricular dyssynchrony as well as the role and importance of assessing dyssynchrony for patient selection.
2) Various echocardiography techniques for assessing mechanical dyssynchrony are described, including tissue Doppler imaging (TDI), speckle tracking, and 3D echocardiography. Major randomized controlled trials on CRT are also summarized.
3) While echocardiography is commonly used, the document notes that no single measure of dyssynchrony is recommended due to variability in results. Larger trials found CRT beneficial primarily in patients with prolonged QRS
Cardiac Resynchronization Therapy and ICDsAhmed Mahmood
Cardiac resynchronization therapy (CRT) uses an implanted device to resynchronize heart ventricle contractions, improving heart pumping efficiency. CRT-Ds additionally treat abnormal heart rhythms. CRT benefits include improved hemodynamics, reduced heart remodeling, and reduced hospitalizations and mortality. CRT is indicated for patients with left ventricular dysfunction, heart failure symptoms, and prolonged QRS duration, especially over 150ms with left bundle branch block. Randomized trials show CRT effectiveness includes these benefits compared to conventional therapy.
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.
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 routine follow-up procedures for patients with cardiac resynchronization therapy (CRT) devices. It recommends using the PBL-STOP method to review the patient's presenting rhythm, battery status, lead status, sensing, thresholds, and observations from the device. The device can provide 14 months of trended data on arrhythmias, activity levels, and fluid status that should be compared to the patient's reported symptoms. The trends can help assess issues like atrial fibrillation, heart rate variability, day and night heart rates, activity levels, fluid buildup, and how much pacing is received. The trend information should be evaluated to see if it matches any signs of worsening heart failure.
This document contains 16 medical cases involving electrocardiogram (ECG) readings and interpretations. Each case provides an ECG image and description of a patient's symptoms or medical history, and asks the reader to identify the diagnosis or next step. The document also includes explanations of various ECG patterns and conditions, such as R on T phenomenon, hyperkalemia, Brugada syndrome, lead reversals, and long QT interval with T-wave alternans. The goal is to teach readers how to properly analyze ECGs and apply that analysis to diagnosing cardiac conditions.
The document discusses sensing in implantable cardioverter defibrillators (ICDs). Reliable sensing of ventricular signals is crucial for ICDs to detect arrhythmias but oversensing can cause inappropriate shocks. While auto-adjusting algorithms generally work, oversensing of T-waves, lead fractures, electromagnetic interference or low R-wave amplitudes can still cause issues. Programming adjustments like sensitivity changes may help but must not compromise ventricular fibrillation detection.
This document contains an ECG quiz that tests the reader's ability to interpret electrocardiograms and diagnose cardiac conditions. It includes 10 multiple choice questions about various ECG readings showing conditions like acute myocardial infarction in different areas of the heart, pericarditis, effects of thrombolysis, and more. The questions aim to evaluate the reader's skill in locating areas of injury, categorizing vessel disease, differentiating disease mimics, and assessing risk of heart block.
This document discusses strategies to minimize right ventricular pacing, which can have deleterious effects. It summarizes several clinical trials that evaluated ventricular versus atrial or dual-chamber pacing. The trials generally found that atrial or dual-chamber pacing reduced atrial fibrillation compared to ventricular pacing, though effects on other outcomes like mortality were less clear. The document recommends that right ventricular pacing be avoided or minimized when possible, through use of AAI pacing, DDD pacing with long fixed AV delays, search AV hysteresis algorithms, or mode-switching algorithms that favor intrinsic conduction.
A 61-year-old man presented with chest pain and was found to have ST-segment elevation in multiple leads on his electrocardiogram (ECG), indicating a heart attack. Additional ECG views showed involvement of the right ventricle. Coronary angiography revealed a 100% blockage of the right coronary artery near the branch supplying the right ventricle. The blockage was opened with a percutaneous coronary intervention, restoring blood flow. The man's condition improved with treatment, and follow-up testing showed his left ventricle function was normal but there was mild dysfunction of the right ventricle.
This document discusses the history and evidence for cardiac resynchronization therapy (CRT). It notes that approximately 25% of heart failure patients have intraventricular conduction delays that cause dyssynchronous contraction. CRT aims to resynchronize contraction by pacing both ventricles simultaneously. Randomized controlled trials found CRT improves symptoms, exercise capacity, and survival in patients with low ejection fraction and wide QRS. Guidelines recommend CRT for class III/IV heart failure patients with LBBB morphology and QRS >120ms. Some evidence also supports benefit in milder heart failure. Response can vary and not all patients respond equally.
Today, in addition to measurement of left ventricular ejection fraction, the simple 12-lead surface ECG remains the only evidence-based means of identifying patients who may obtain the substantial benefits of CRT
This document discusses various types and assessment of left ventricular dyssynchrony. It defines electrical and mechanical dyssynchrony. It describes different types of dyssynchrony including atrioventricular, interventricular, and intraventricular dyssynchrony. It discusses various echocardiography techniques to demonstrate and quantify each type of dyssynchrony, including M-mode, tissue Doppler, speckle tracking, and 3D echocardiography. It also mentions the use of MRI to assess dyssynchrony. The key application of assessing dyssynchrony is to predict response to cardiac resynchronization therapy in patients with heart failure.
Hormonlar nöroendokrin sistem (yani sinir hücresi olarak bilinen nöronlar ve çeşitli salgı bezleri) tarafından yapılırlar. Hormonlar özellikle yüksek yapılı hayvanlarda sinyal iletimi, davranış ve enerji metabolizmasında önemli roller üstlenmişlerdir ve kanla hedef dokulara taşınırlar
Effects of Norepinephrine and Epinephrine on CardiomyocyteAldrin Corañez
The document describes the process of how epinephrine and norepinephrine trigger contraction of cardiac muscle cells. It involves:
1) The binding of epinephrine/norepinephrine to β-adrenergic receptors on cardiac cells, activating associated G proteins.
2) The G proteins activate adenylate cyclase, catalyzing the conversion of ATP to cyclic AMP (cAMP).
3) cAMP activates protein kinase A, which phosphorylates proteins involved in calcium ion movement and muscle contraction.
Noradrenaline is a potent vasoconstrictor used to treat profound hypotension, usually in combination with dopamine, when other inotropes have failed in sepsis patients. It is administered by IV infusion at an initial dose of 0.05-0.1 microgram/kg/minute, titrated up to a maximum of 1-1.5 microgram/kg/minute. The drug comes in 2mg/2mL ampoules and is diluted for infusion based on the baby's weight to achieve a rate of 0.1 microgram/kg/minute, administered over 24 hours and monitored for potential side effects like hypertension and local tissue damage from extravasation.
Noradrenaline acts as a neurotransmitter between sympathetic postganglionic nerves and the organs they innervate. When an action potential reaches the nerve terminal, noradrenaline is released into the synaptic cleft and binds to alpha adrenoreceptors on nearby cells. This causes vasoconstriction and increases both systolic and diastolic blood pressure, raising mean arterial pressure. Noradrenaline interacts with various other drugs and medications and can cause side effects like anxiety, dizziness, and tremors. It should be used cautiously in patients with certain medical conditions.
Este documento describe la síntesis y función de las catecolaminas norepinefrina, epinefrina y dopamina. Se sintetizan a partir de la tirosina y se liberan en las sinapsis postganglionares para regular funciones como la presión arterial a través de los receptores alfa y beta adrenérgicos.
Norepinephrine and epinephrine are stress hormones involved in the fight or flight response. Norepinephrine is released by neurons and the adrenal gland, while epinephrine is produced solely in the adrenal gland. Both play essential roles in stress responses, blood pressure, and metabolism. Serotonin is a neurotransmitter that regulates mood, appetite, sleep, and cognitive functions. Imbalances in serotonin have been linked to depression, suicide, impulsivity, and aggressiveness.
Otto Loewi discovered the first neurotransmitter, acetylcholine, in 1921 through an experiment using two frog hearts. He found that electrical stimulation of the vagus nerve of one heart caused it to slow down, and the same effect was seen in the second heart, showing that a chemical was being transmitted. Neurotransmitters meet four criteria: they are synthesized and stored in neurons, released at synapses, mimic the action of natural transmitters as drugs, and are removed from synapses. There are two main classes of neurotransmitters - small molecules like acetylcholine, dopamine, serotonin; and peptides. Small molecules are synthesized in axon terminals while peptides are made in cell bodies.
This document summarizes neurotransmitters and their mechanisms of action. It defines neurotransmitters as chemical substances that transmit nerve impulses across synapses. There are over 50 known neurotransmitters that are classified biochemically and physiologically as either excitatory or inhibitory. The document describes the general mechanisms of several major neurotransmitters including acetylcholine, catecholamines, serotonin, histamine, amino acids, and neuropeptides. It explains how they are synthesized, stored in vesicles, released, and deactivated in the synaptic cleft.
Epinephrine is a catecholamine hormone produced by the adrenal medulla. It plays an important role in the fight or flight response by increasing heart rate, redirecting blood flow, and raising blood pressure and blood glucose levels. Epinephrine is used medically to treat cardiac arrest, severe hypotension, and anaphylaxis. It is administered via injection using devices like EpiPens. Epinephrine acts on alpha and beta adrenergic receptors and stimulates the sympathetic nervous system.
Epinephrine is a hormone secreted by the medullas of adrenal glands that is also used as a drug. It is used as a stimulant in cardiac arrest, vasoconstrictor in shock, bronchodilator, and antispasmodic in bronchial asthma. Epinephrine must be stored below 25 degrees Celsius, protected from light, and not refrigerated. It is indicated for emergency treatment of anaphylaxis, bronchospasm, asthma, and cardiac failure but has contraindications for people with high blood pressure, diabetes, heart disease, children under 30 kg, and lung or mental health conditions. Common side effects include abnormal touch sensation, pain, discoloration, fainting
This document discusses adrenergic receptors and modulators. It describes the sympathetic nervous system and neurotransmitters like norepinephrine, epinephrine, and dopamine. Norepinephrine is stored in synaptic vesicles and released via calcium-dependent fusion. Release can be modulated by prejunctional autoreceptors and heteroreceptors. There are alpha and beta adrenergic receptors which are G-protein coupled and have various effects. Drugs can affect receptors as agonists or antagonists and are used to treat conditions like hypertension and heart failure.
Neurotransmitters are chemical messengers that transmit signals between neurons. They are synthesized in the presynaptic neuron, stored in vesicles, released into the synaptic cleft upon an action potential, and bind to receptors on the postsynaptic neuron. Common neurotransmitters include acetylcholine, dopamine, GABA, glutamate, and serotonin. Neurotransmitters are involved in communication between neurons and play a role in diseases when their function is impaired.
Electrocardiography (ECG) is used to diagnose myocardial infarction by detecting changes in the heart's electrical activity. ECG can identify the infarct-related artery by showing different ST segment elevation patterns corresponding to specific coronary artery occlusions. Assessment of ST segment resolution on ECG is also useful for guiding reperfusion therapy, as a reduction of over 70% in ST segment elevation within 90 minutes indicates effective treatment. The hallmarks of acute myocardial infarction on ECG are ST segment elevation in leads overlying the infarct area and ST depression in reciprocal leads.
This document describes a case study of a patient with Brugada syndrome who experienced progression of his heart condition. The patient initially presented with ventricular fibrillation and was found to have a low-voltage area in his right ventricle. One year later, he experienced recurrent ventricular fibrillation. Mapping of his heart found the low-voltage area had increased in size. Biopsies of the area found myocardial inflammation and necrosis. Radiofrequency ablation successfully terminated arrhythmias but also induced polymorphic ventricular tachycardia on occasion. The case suggests structural abnormalities in Brugada syndrome can progress and lead to arrhythmia recurrence.
This document summarizes a study on two patients with Swyer-James (Macleod's) syndrome, which is characterized by unilateral hyperlucency of the lung. The first patient, a 52-year-old woman, presented with shortness of breath and was found to have a hyperlucent right lung. Pulmonary function tests showed reduced capacity. A lung scan showed almost no perfusion to the right lung. A pulmonary angiogram revealed a diminutive right pulmonary artery. The second patient is also described as demonstrating features of this syndrome. The authors conducted further tests to characterize the diagnostic criteria and pulmonary circulation in cases of this syndrome.
The document discusses the physiological basis of the electrocardiogram (ECG). It defines the ECG and describes how it captures the electrical activity of the heart during each contraction cycle. It explains the cardiac action potentials and the conductive system of the heart. It also discusses the waves that make up the ECG (P, QRS, T), the intervals and segments, and how ECGs are interpreted to diagnose conditions like heart attacks and arrhythmias.
The study analyzed arterial pulse recordings from 1,005 subjects aged 2-91 years using a new tonometry technique. Three main findings were observed with increasing age: (1) pulse amplitude increased in all artery sites, (2) diastolic decay steepened and diastolic waves diminished, (3) carotid pulses showed a merging of two systolic peaks. These changes reflect increased arterial stiffness and earlier wave reflections with age.
This document discusses various biomedical recorders used to measure electrical signals from the body. It focuses on electrocardiography (ECG) which measures the heart's electrical activity, and phonocardiography (PCG) which records heart sounds. For ECG, it describes the typical waveform, applications in diagnosis, and 12-lead measurement setup. For PCG, it explains the different heart sounds recorded, microphones used, writing methods, medical applications in detecting murmurs and valvular lesions, and special applications including fetal and esophageal PCG.
The electrocardiograph (ECG) is an instrument which records the electrical activity of the heart. ... ECG provides valuable information about a wide range of cardiac disorders such as the presence of an inactive part (infarction) or an enlargement (cardiac hypertrophy) of the heart muscle.
This document summarizes antiarrhythmic drug therapy for atrial tachyarrhythmias such as atrial flutter and atrial fibrillation. It discusses the mechanisms of these arrhythmias including theories of circus movement, multiple foci, and fractionated contractions. It also discusses classification schemes and the role of the size and electrical remodeling of the atria. Current therapeutic approaches include antiarrhythmic drugs, catheter ablation using radiofrequency energy, and surgical ablation techniques. Radiofrequency ablation of the isthmus between the inferior vena cava and tricuspid annulus is the primary treatment for atrial flutter, while the Maze procedure is used surgically.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
The document discusses the cardiac cycle, including its history, events, phases, and investigations. It provides details on the comparative physiology of the cardiac cycle between mammals and humans. Recent advances discussed include improved medical imaging techniques and minimally invasive heart procedures. The applied physiology of the cardiac cycle focuses on its role in regulating blood flow, pressure, and cardiac output in response to physiological demands through autonomic nervous system control.
This document provides information about electrocardiography (ECG) including its history, components, interpretation, and procedure. It discusses that ECG was invented in 1901 by Enthovan to record electrical impulses of the heart. It describes the normal conduction system, waves (P, Q, R, S, T), segments, intervals of ECG and placement of 12 leads. The document outlines the procedure for performing an ECG including preparing the patient, connecting the leads, and interpreting the results. It emphasizes the importance of properly performing and interpreting ECG to assess cardiac function and diagnose cardiac conditions.
This document provides an overview of the biophysics of the cardiovascular system, including:
- The mechanical properties of blood vessels and how blood pressure relates to vessel size.
- Factors influencing blood flow and how flow becomes turbulent above a critical velocity.
- How peripheral resistance affects blood pressure in different parts of circulation.
- The mechanical work and power output of the heart during each contraction.
- The processes of capillary ultrafiltration and kidney filtration and reabsorption.
- Common techniques for measuring blood pressure non-invasively.
An ECG is a record of the heart's electrical activity over time captured by skin electrodes. It is a diagnostic tool used to detect cardiac arrhythmias, conduction abnormalities, electrolyte disturbances, and screen for heart disease. An ECG involves placing electrodes on the skin of the limbs and chest to record the heart's electrical activity through 12 leads that detect the heart from different angles based on Einthoven's triangle. The ECG trace shows the P, QRS, and T waves that correspond to atrial depolarization, ventricular depolarization and repolarization.
This case report describes an 82-year-old male who developed intracardiac shunts following a redo aortic valve replacement surgery. Doppler echocardiography detected shunts from the left ventricle outflow tract across the membranous septum into the right atrium, right ventricle, and left atrium. The anatomical basis for this complication is the proximity and relationship of the thin membranous septum to the aortic root, tricuspid valve, and ventricular chambers. Aggressive debridement during valve surgery can cause injury and necrosis of the membranous septum, leading to fistula formation over time. While the shunts were initially small and asymptomatic, they could enlarge
An ECG is a recording of the electrical activity of the heart over time using skin electrodes. It is the gold standard for diagnosing cardiac diseases in a noninvasive manner. The ECG records the P wave from atrial depolarization, the QRS complex from ventricular depolarization and repolarization of the atria, and the T wave from ventricular repolarization. Proper electrode placement and ensuring good skin contact is important for obtaining an accurate recording. The recording is then analyzed based on heart rate, rhythm, intervals, wave amplitudes and shapes to identify any abnormalities.
This article discusses cardiac abnormalities discovered during long-term monitoring for epilepsy. Five case studies are presented where cardiac issues were found during EEG monitoring, including non-ictal and ictal related arrhythmias such as asystole, bradycardia, and tachycardia. The article emphasizes the importance of reviewing the electrocardiogram channel during long-term EEG monitoring, as it can reveal undiagnosed cardiac problems that warrant further investigation and treatment. Catching these issues could prevent serious health consequences for patients.
Trio of Rheumatic Mitral Stenosis, Right Posterior Septal Accessory Pathway a...Ramachandra Barik
A 57-year-old male presented with recurrent palpitations. He was diagnosed with rheumatic mitral stenosis, right posterior septal accessory pathway and atrial flutter. An electrophysiological study after percutaneous balloon mitral valvotomy showed that the palpitations were due to atrial flutter with right bundle branch aberrancy. The right posterior septal pathway was a bystander because it had a higher refractory period than the atrioventricular node.
This document discusses ECG signals and how they are used to monitor heart activity. It provides information on cardiac action potentials, how electrodes are placed on the body to detect electrical changes during heartbeats, and how different lead placements can provide varying levels of detail. Common ECG waveforms like the P wave, QRS complex, and T wave are examined, as well as how abnormalities may present themselves in the timing or amplitudes of these waves. Different types of arrhythmias and what they indicate about conduction or muscle issues are also overviewed.
The electrocardiogram (ECG or EKG) records the electrical activity of the heart. Electrodes placed on the skin detect currents produced by the propagation of action potentials through the heart muscle with each heartbeat. The ECG produces 12 tracings from different electrode combinations that can identify abnormalities in conduction pathways, enlarged heart structures, damaged heart regions, and causes of chest pain. A normal ECG shows three distinct waves - the P wave from atrial depolarization, the QRS complex from ventricular depolarization, and the T wave from ventricular repolarization.
Similar to Adrenaline noradrenaline-investigation (20)
Cell Therapy Expansion and Challenges in Autoimmune DiseaseHealth Advances
There is increasing confidence that cell therapies will soon play a role in the treatment of autoimmune disorders, but the extent of this impact remains to be seen. Early readouts on autologous CAR-Ts in lupus are encouraging, but manufacturing and cost limitations are likely to restrict access to highly refractory patients. Allogeneic CAR-Ts have the potential to broaden access to earlier lines of treatment due to their inherent cost benefits, however they will need to demonstrate comparable or improved efficacy to established modalities.
In addition to infrastructure and capacity constraints, CAR-Ts face a very different risk-benefit dynamic in autoimmune compared to oncology, highlighting the need for tolerable therapies with low adverse event risk. CAR-NK and Treg-based therapies are also being developed in certain autoimmune disorders and may demonstrate favorable safety profiles. Several novel non-cell therapies such as bispecific antibodies, nanobodies, and RNAi drugs, may also offer future alternative competitive solutions with variable value propositions.
Widespread adoption of cell therapies will not only require strong efficacy and safety data, but also adapted pricing and access strategies. At oncology-based price points, CAR-Ts are unlikely to achieve broad market access in autoimmune disorders, with eligible patient populations that are potentially orders of magnitude greater than the number of currently addressable cancer patients. Developers have made strides towards reducing cell therapy COGS while improving manufacturing efficiency, but payors will inevitably restrict access until more sustainable pricing is achieved.
Despite these headwinds, industry leaders and investors remain confident that cell therapies are poised to address significant unmet need in patients suffering from autoimmune disorders. However, the extent of this impact on the treatment landscape remains to be seen, as the industry rapidly approaches an inflection point.
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.
low birth weight presentation. Low birth weight (LBW) infant is defined as the one whose birth weight is less than 2500g irrespective of their gestational age. Premature birth and low birth weight(LBW) is still a serious problem in newborn. Causing high morbidity and mortality rate worldwide. The nursing care provide to low birth weight babies is crucial in promoting their overall health and development. Through careful assessment, diagnosis,, planning, and evaluation plays a vital role in ensuring these vulnerable infants receive the specialize care they need. In India every third of the infant weight less than 2500g.
Birth period, socioeconomical status, nutritional and intrauterine environment are the factors influencing low birth weight
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.
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
“Psychiatry and the Humanities”: An Innovative Course at the University of Mo...Université de Montréal
“Psychiatry and the Humanities”: An Innovative Course at the University of Montreal Expanding the medical model to embrace the humanities. Link: https://www.psychiatrictimes.com/view/-psychiatry-and-the-humanities-an-innovative-course-at-the-university-of-montreal
- 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
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Promoting Wellbeing - Applied Social Psychology - Psychology SuperNotesPsychoTech Services
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Are you looking for a long-lasting solution to your missing tooth?
Dental implants are the most common type of method for replacing the missing tooth. Unlike dentures or bridges, implants are surgically placed in the jawbone. In layman’s terms, a dental implant is similar to the natural root of the tooth. It offers a stable foundation for the artificial tooth giving it the look, feel, and function similar to the natural tooth.
2. Studies of the Arterial Pulse Wave
ARTHUR W. FEINBERG, M.D. AND HENRY LAX, M.D.
With the technical assistance of William Urban
Previous studies have shown abnormalities of the arterial pulse wave in hypertensive
subjects of all age groups. The major change has been diminution to disappearance
of the dicrotic wave. The pharmacologic differences between epinephrine and norepi-
nephrine offer a means of studying the mechanism of this change in the dicrotic wave.
In the present study, normotensive subjects have had transient hypertension induced
by the infusion of epinephrine and norepinephrine. The different effects of these drugs
on their arterial pulse waves have been recorded.
I N A previous report,' describing observa- The pharmacologic studies of Goldenberg
tions on the arterial pulse wave in human and his group8 have shown that although both
subjects, a new technic was introduced for epinephrine and norepinephrine produce com-
recording the pulse wave without intra-arte- parable degrees of hypertension, they do so in
rial puncture. The method has been shown to different ways. The hypertensive action of
be sensitive and to give reproducible results. epinephrine in man is due primarily to a
The accuracy of the recordings has been dem- large increase in cardiac output that over-
onstrated by the similarity of simultaneous balances a decrease in total peripheral resist-
intra-arterial and extra-arterial tracings. ance. On the other hand, hypertension
Figures 1 and 2 show typical instances of induced by norepinephrine is produced in
normal and abnormal arterial pulse waves as man by a striking increase in peripheral re-
recorded by this technic. The major difference sistance with little or no change in the cardiac
in the abnormal cases appears to be diminu-
tion to disappearance of the dicrotic wave.
These changes in the dicrotic segment of the
arterial pulse wave have been found in hyper-
tensive subjects of all age groups as well as
in patients with generalized arteriosclerosis,
coronary arteriosclerosis, and diabetes melli-
tus.
The dicrotic wave has been ascribed to a
reflected wave from the recoil of the blood
column against the closed aortic valve. More
recent studies2-7 indicate that peripheral fac-
tors also play a role in the formation of the
dicrotic wave. The technic described herein
seemed to offer another means of studying the
mechanism of the dicrotic wave.
From the Research Service, First (Columbia Uni-
versity) Division, Goldwater Memorial Hospital, De- FIG. 1. Normal arterial pulse waves recorded from
partment of Hospitals, New York, N.Y., and the the third digit of a healthy 25 year old man. The
Department of Medicine, College of Physicians and vertical lines are time signals 0.1 second apart and the
Surgeons, Columbia University. horizontal lines represent pressure increments of 10
Supported in part by grants from the Albert and inmn. Hg in the cuff applied about the finger. The
Mary Lasker Foundation and the New York Heart cuff pressure (P) is recorded simultaneously but inde-
Association and by a grant from George and Monique pendently of the components of the pulse wave. Note
Uzielli. initial wave (I) and well defined dicrotic wave (D).
125 Circulation, Volume XVIII? December 195
Downloaded from circ.ahajournals.org by on October 13, 2010
3. -1 2''( FEINBERG, LAX
output. It, al))eared that investigation of the cause tile (liaplirlaglii to (lefect according to their
effeet of these 2 drugs, with their differeni intensity and direction.
central and peripheral actions, Light help to Deflections of the diaphragm are transmitted by
mechanical linkage either to a Statham absolute
explain the inode of origin of the dicrotic pressure strain gage or to a piezo-electric crystal
wave. Accordingly, the present study has cartridge that generates electric energy according
been carried out on the effect of intravenous to the mechanical motion imposed upon it. The
infusions of epinephrine and norepinephrine, crystal unit (Astatic inicrophone cartridge D-104)
iii quantities sufficient to produce signifieaint has an output of -45 db. referred to 1 volt per
micro bar. Output from the crystal is amplified
hypertension, on the dicrotie wave of pre- with a class A balanced push-pull amplifier with
sumai11.bly healthy, n ormotensive individuals. continuous variable gain from 0 to 16 db. max.
The amplifier feeds a dual-coil string-type mirror
METHOD AND TECHNIC g(alvanometer.
Permanent recordings are made on 12 ciii. wide
Ai sensitive rubber cuff with an inelastic backing electrocardiographic paper, with a Cambridge 3-
is applied to the external surface of the limb or speed camera. Camera speeds are 121/2, 25, or
ligit. The cuff consists of a thin rectangular 50 inma. per second. Timning. marks appear as
ineiabrane 11/2 by 3 inches cemented at the edges equally spaced vertical lines. Recordings can also
to a backing piece of rubberized cloth. A 1/8 be mna(le intra-arterially amiAd takeni on (lireet-writ-
inch I.D. nipple attached at the (enter of the cloth ing electrocardiograph papem.
is connected to a 3 foot length of 1/8 inch rubber The frequency response of the entire systemi
tubing. This tubing serves the dual purpose of frcomn cuff to galvanometer shows the response to
inflating the cuff and connecting it to the recording le substantially flat to 40 cps., which is well above
chamber of a differential pressure transducer. The the 5 to 6 cycle range encountered in studying
c uff is attached by an inelastic strap to the cx- arterial pulse waves.
treinity to be examined. Continuously variable gain control enables the
The differential pressure tramnsducer consists of operator to standardize the amplitude of record-
a circular beryllium copper diaphraemn 0.006 inch inlgs without affecting the conmfiguratiomi of the
thick and 11/2 inches ill diaimieter separating 2 arterial pulse wave. This feature is of value in
air chambers. Air pressure required to inflate the comparative studies over a period of time on the
cuff is introduced to both chambers, causing no same subject. Recording at the same basic ampli-
deflection of the diaphragm. Pressure disturbances tude permits standardized conditions insofar as the
originating at the cuff, however, are conducted to instrument itself is concerned. The only variables
the recording chamber only. These disturbances then lie with the patient.
FIG. 2. Left. Abnormal arterial pulse wave. Note diminished size of dicrotic wave (D).
The cuff pressure (P) is also recorded. Right. M1ore severely albnormal arterial pulse wave
sliowiiig aI complete albesenee of the dicrotic wave.
Downloaded from circ.ahajournals.org by on October 13, 2010
4. 4_t,I - _§fl.-,et{ _, -_, -
STUDIES OF ARTERIAL PULSE WAVE
A.E. B.P. 120/80 (1)
I
t
t
-4-
BEFORE
INFUSION
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nand needle (18 gage, 2 3/64 inch. no. 488
LNR) was introduced into a brachial artery.
Pulse pressure waves were transmitted to a
Statham P-23A absolute pressure strain gage
and a continuous intra-arterial pulse wave
tracing was begun. After a control period
lasting from 2 to 5 minutes, a previously in-
troduced infusion of glucose and water was
changed to an infusion containing either nor-
epinephrine (Levophed) or epinephrine (Sii-
_1
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A.E. B.P.
A.B.
MIX*. ATR
FIG. 3. Effect of intravenous infusion of norephiinephlrine on the arterial pulse wvave of a
32 year old normotensive male subject. Note the diminution of the dicrotic wave (D) in .d
and its virtual disappearance in 3. It starts to return in 4 after the blood I)ressure has
returned to control levels.
All arterial pulse wave tracings during this
study were recorded intra-arterially. A Cour-
170/110 (2}
1 MINOF NORFX-NP
B.Ph. 12O10 (1L)
D~i
N.UP.N3_
STOPPED
N_
a
RE SULTS
IVith iNorepi e phrinie
i
Nine normotensive, presuniably healthy
1127
subjects were given norepinephrine by intra-
venous infusion. In all individuals, as the
blood pressure rose, the well defined dierotic
wave of the control intra-arterial pulse wave
became smaller and finally disappeared comn-
pletely. Upon discontinuing the norepineph-
rine, the dicrotic wave reappeared within mini-
utes of the return of the blood pressure to
prarenin, Winthrop). The blood pressure was control levels.
taken by cuff at 1 minute intervals and in Figure 3 is. illustrative of these ehlatges.
some cases was also recorded on the tracing.
The subject was a, 32 year old male hospital
After 3 minutes of sustained elevation of sys- porter with no (clinical evidences of vascular
tolic and diastolic pressures, the intravenous disease. His resting blood pressure was
infusion was discontinued but the continuous 120/80, and a well defined dicrotic wave is
intra-arterial pulse wave recording was main- seen on his initial pulse tracing. The blood
tained until the configuration of the pulse pressure rose to 170/110 after 1 minute of
wave had about returned to its control ap-
intravenous norepinephrine in doses of 0.4 1Lg.
pearance. This usually took 10 to 15 minutes. per Kg. per minute and the dicrotic wave be-
The blood pressure invariably fell to its base- came markedly smaller. The double peaking
line levels before the control pulse w*ve con- of the anaerotie wave has been seen ins other
figuration was restored. subjects with hypertension, whether natural
Downloaded from circ.ahajournals.org by on October 13, 2010
5. 1128 F1INBERG, LAX
XPI NEPBRIN TLS
S.S. B.P.122/80 3.S. B.P.145/80 13.5 . B.P.160/88
I.BeUOS 1 MIN. OF 2 M OF
ImJsion EMIN PHIRINE 2PINEFPRINE
m~~~~~~~~~~~~~~~~~~~
. . .
5 MIN.O SMIN. OF 6 MIN. AFTER
FG4.NfeeRINE ePINErINeOI EPINEPHINE STOPPED
FIG. 4. Effect of intravenous infusion of epinephrine oil arterial pulse wave. Although the
amplitude of the entire ws-ave increases with rise iII blocod pressure, dicrotic wave (D) is
elearly seen at all times.
or induced. Its cause remains unexplained. ,ug. Kg. per minute for a total of 8 mimn-
per
After 3 mitiutes of sustained hypertension, the utes. During this time the blood pressure
dierotic wave completely disappeared. Five rose from 122/80 to a sustained peak of 220/
minutes after stopping the norepinephrine in- 110. Although the form of the arterial pulse
fusion, the blood pressure had returne to its wave reflected this chanige ini the blood pres-
control level of 120/80 and the dicrotic wave sure, the dicrotic wave remainled clearly de-
had started to become evident agaiin. The fined in all tracings.
study was discontinued in this patient before In one of the normotensive iubjects (a 30
the dicrotic wave had recovered its full height. ear old male technician) epinephrine and
WVith EpincephrineC norepinephrine were given consecutively, with
a 15 minute interval betweeni the administra-
Four normotensive, presumably healthy tion of the 2 drugs to permit return of the
subjects were givens epinephrille intravenous- control pattern. The typical difference be-
l
v. Despite elevations of the systolic and tween the effects of epinephrine and norepi-
diastolic blood pressure comparable to those nephrine are demonstrated in this case (fig.
seemi ini the experiments with norepinephrine,
5). Both drugs produced approximately the
no basic chamrge was noted in the conifigurationi same elevation of blood pressure. Norepineph-
of the dicrotic wave. Specifically, the di- rime caused a complete disappearance of the
crotic wave was neither diminished nor had dicrotic wave, whereas the dicrotic wave was
disappeared in amiy of the subjects studied, undisturbed after the administration of epi-
even though the over-all amplitude of the
nephrine.
pulse wave increased as the blood pressure DISCUSSION
rose.
Figure 4 illustrates these changes in a 21 The mode of origin and propagation of the
year old female hospital technician. Epineph- dicrotic wave has been investigated for yars
rine was infused intravenously in doses of 0.4 but remains incompletely understood. The
Downloaded from circ.ahajournals.org by on October 13, 2010
6. STUDIES OF ARTERIAL PULSE WAVE1 1129
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A.M. B.P. 134/86 A.M. BLP. 176/98 Am. B.P. 186/122 A.M. B.P. 146/82
BWEB INFUION z uND. 0
2 uRmT 5 KIN. 01
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A.M. B.P. 138/86 A.M. B.P. 190/114 A.M. B.P. 138/88
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FIG. 5. Effect of epinephrine and norepinephrine given consecutively to the same patient
after a 15 minute interval. Note persistence of the dicrotic wave (D) in the epinephrine
tracings and its disappearance after norepinephrine. Both drugs gave comparable elevations
of blood pressure.
classic theory explains the dicrotic peak as tients who received norepinephrine, the di-
a reflected wave initiated by the recoil of the crotic wave was abolished or markedly re-
arterial blood column against the closed aor- duced in size, despite a similar rise in blood
tic valve. The studies of Hamilton, Reming- pressure. These findings are well explained
ton, and Dow,2-5 Wiggers,6 and Alexander7` by what is known of the pharmacologic differ-
have shown that the arterial pulse wave is. ences between the 2 drugs. Goldenberg and
progressively transformed in its passage down others8 have shown that the actions of epi-
the aorta and its arterial branches, suggesting nephrine and norepinephrine in man are sim-
that the physiologic state of the peripheral ilar only in that they both produce significant
vessels may play an important part in influ-- elevations of blood pressure. The hyperten-
encing the appearance of the dicrotic wave.. sive effect of norepinephrine is due to an in-
Our initial studies' also suggested that crease of total peripheral resistance, with no
changes in the peripheral arteries determine significant change in cardiac output. Epi-
the presence or absence of the dicrotic wave nephrine, on the other hand, raises the blood
of the arterial pulse. It was found, for exam- pressure predominantly by a central action
ple, that the dicrotic wave was markedly ab- on the heart, iiicreasing the rate and force of
normal in hypertensive subjects of all age cardiac contractions and the cardiac output.
The peripheral resistance actually decreases,
groups, in patients with peripheral arterio-
because of an over-all vasodilating action.
sclerosis, and in diabetic patients as young as The marked difference between the effects of
14 years of age. epinephrine and norepinephrine on the di-
The results of the present study would seem erotic wave thus support the hypothesis that
to support this view. In the 4 subjects given changes in the tonus of the arterial wall have
epinephrine, the dicrotic wave was not basi- significant effects on the configuration of the
cally altered although the blood pressure rose distinctive waves seen in arterial pulse trac-
significantly. On the other hand, in all 9 pa- ings.
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7. 1130 3FEINBERG, LAX
SUMMARY dicrotic in association con le augmento del
Previous studies have shown a diminution pression de sanguine. Le unda dicrotic re-
to disappearance of the dicrotic wave in the appareva quando le pression de sanguine re-
presence of clinical evidences of arteriosclero- tornava a nivellos normal. Del altere latere,
sis, diabetes mellitus, and hypertensive vas- 4 subjectos recipiente epinephrina exhibiva
cular disease. nulle alteration del unda dicrotic in despecto
Transitory hypertension was induced in 13 de comparabile augmentos del pression de san-
normotensive subjects by intravenous infu guine.
sions of either norepinephrine or epinephrine. Le differentia inter le effectos exercite super
A continuous intra-arterial pulse-wave tracing le undas dicrotic es possibilemente relationate
was recorded from the brachial artery before, al differentias pharmacologic inter le duo dro-
during, and after the infusions in most in- gas. Hypertension a epinephrina es producite
stances. per un augmento del rendimento cardiac in
The pulse waves of all 9 subjects given nor- despecto de un reducite total resistentia
epinephrine demonstrated disappearance of peripheric. Hypertension a norepinephrina
the dicrotie wave as the blood pressure rose. es causate per un augmento del resistentia
The dicrotic wave reappeared as the blood peripheric con pauc o nulle alteration del
pressure returned to normal. Contrariwise, rendimento cardiac.
4 subjects given epinephrine had no change Le datos presentate supporta le theoria que
in the dicrotic wave despite comparable ele- factores peripheric ha un rolo importante in
vation of the blood pressure. le production del culmine dicrotic que charae-
The different effects on the dicrotic wave terisa le unda del pulso arterial.
may be related to the pharmacologic differ- REFERENCES
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