Photoplethysmographic assessment of pulse wave reflection: Blunted response to mellitus -adrenergic vasodilation in type II diabetes 2
endothelium-dependent beta
1) This study examined the predictive value of Nt-proBNP levels for postoperative atrial fibrillation (AF) in patients undergoing cardiac surgery with cardiopulmonary bypass.
2) The study found that Nt-proBNP levels were significantly higher in patients who developed postoperative AF compared to those who did not, particularly at the end of bypass and 4 hours post-surgery.
3) A Nt-proBNP threshold value of 353.5 pg/ml at the end of bypass predicted postoperative AF with 71% sensitivity and 84% specificity.
Noninvasive Cardiac Output Estimation Using a Novel
Photoplethysmogram Index
31st Annual International Conference of the IEEE EMBS Minneapolis, Minnesota, USA, September 2-6, 2009
7 Adequacy Of Perfusion During Cardiopulmonary BypassDang Thanh Tuan
The document discusses various parameters for determining the adequacy of perfusion during cardiopulmonary bypass (CPB), including arterial flow rates, pressures, hematocrit levels, oxygen consumption, and venous oxygen saturation. While standards were established decades ago, newer evidence suggests the need to re-evaluate perfusion techniques given improvements in CPB systems and reports of adverse neurological outcomes. A range of factors like patient characteristics, anesthesia, and disease states can impact optimal perfusion values.
7 Adequacy Of Perfusion During Cardiopulmonary BypassDang Thanh Tuan
The document discusses several factors that may impact the adequacy of perfusion during cardiopulmonary bypass (CPB), including arterial flow rates, oxygen consumption, venous oxygen saturation, lactate levels, the arterial-venous carbon dioxide gradient, arterial pressures, vascular resistance, and autoregulation. While standards for some perfusion parameters were established decades ago, new evidence suggests re-evaluating perfusion techniques to optimize patient outcomes.
Nitrous oxide is a colourless gas that is commonly used for sedation and pain relief, but is also used by people to feel intoxicated or high. It is commonly used by dentists and medical professionals to sedate patients undergoing minor medical procedures
This document describes a study examining the resolution of the S wave in lead I of electrocardiograms as a potential marker of successful thrombolysis in patients with acute pulmonary embolism. The study analyzed ECGs from 200 patients before and after thrombolysis treatment. Patients were classified as having successful or unsuccessful thrombolysis based on clinical outcomes and echocardiography. Rapid reduction of the S wave in lead I within 24 hours after treatment was found in 90% of patients with successful thrombolysis, but no patients with unsuccessful thrombolysis, indicating it may be a useful bedside tool for predicting thrombolysis efficacy. Two case studies are also presented demonstrating application of this ECG criterion.
1) This study examined the predictive value of Nt-proBNP levels for postoperative atrial fibrillation (AF) in patients undergoing cardiac surgery with cardiopulmonary bypass.
2) The study found that Nt-proBNP levels were significantly higher in patients who developed postoperative AF compared to those who did not, particularly at the end of bypass and 4 hours post-surgery.
3) A Nt-proBNP threshold value of 353.5 pg/ml at the end of bypass predicted postoperative AF with 71% sensitivity and 84% specificity.
Noninvasive Cardiac Output Estimation Using a Novel
Photoplethysmogram Index
31st Annual International Conference of the IEEE EMBS Minneapolis, Minnesota, USA, September 2-6, 2009
7 Adequacy Of Perfusion During Cardiopulmonary BypassDang Thanh Tuan
The document discusses various parameters for determining the adequacy of perfusion during cardiopulmonary bypass (CPB), including arterial flow rates, pressures, hematocrit levels, oxygen consumption, and venous oxygen saturation. While standards were established decades ago, newer evidence suggests the need to re-evaluate perfusion techniques given improvements in CPB systems and reports of adverse neurological outcomes. A range of factors like patient characteristics, anesthesia, and disease states can impact optimal perfusion values.
7 Adequacy Of Perfusion During Cardiopulmonary BypassDang Thanh Tuan
The document discusses several factors that may impact the adequacy of perfusion during cardiopulmonary bypass (CPB), including arterial flow rates, oxygen consumption, venous oxygen saturation, lactate levels, the arterial-venous carbon dioxide gradient, arterial pressures, vascular resistance, and autoregulation. While standards for some perfusion parameters were established decades ago, new evidence suggests re-evaluating perfusion techniques to optimize patient outcomes.
Nitrous oxide is a colourless gas that is commonly used for sedation and pain relief, but is also used by people to feel intoxicated or high. It is commonly used by dentists and medical professionals to sedate patients undergoing minor medical procedures
This document describes a study examining the resolution of the S wave in lead I of electrocardiograms as a potential marker of successful thrombolysis in patients with acute pulmonary embolism. The study analyzed ECGs from 200 patients before and after thrombolysis treatment. Patients were classified as having successful or unsuccessful thrombolysis based on clinical outcomes and echocardiography. Rapid reduction of the S wave in lead I within 24 hours after treatment was found in 90% of patients with successful thrombolysis, but no patients with unsuccessful thrombolysis, indicating it may be a useful bedside tool for predicting thrombolysis efficacy. Two case studies are also presented demonstrating application of this ECG criterion.
This document provides guidelines for the management of severe sepsis and septic shock according to the Surviving Sepsis Campaign. It outlines the initial resuscitation goals of fluid resuscitation, antibiotic administration, lactate clearance, and maintaining a central venous oxygen saturation of greater than 70% through fluid administration, vasopressors if needed, and dobutamine. The use of stress-dose steroids and recombinant human activated protein C for certain high-risk patients is also recommended.
LCZ696 was more effective than enalapril in reducing the risks of CV death and HF hospitalization, CV death, HF hospitalization, and all-cause mortality in patients with heart failure with reduced ejection fraction. LCZ696 also provided incremental improvements in symptoms and physical limitations. LCZ696 was better tolerated than enalapril with lower rates of symptomatic hypotension, hyperkalemia, renal impairment, and cough.
Linking HFpEF and Chronic kidney disease magdy elmasry
Cardio-renal interactions
Introducing nephro-cardiology
{ or cardio-nephrology }
Where are we in 2022 with HFpEF ?CKD in HFpEF { or HFpEF in CKD } Cardiorenal
Syndrome .Four-step
HFA-PEFF diagnostic algorithm
heterogeneity in patients with HFpEF.Phenotyping HFpEF :
Beyond EF.Management of HFpEF .patients with HF on dialysis
This document summarizes the pathophysiology and anesthetic management considerations for patients with pulmonary hypertension. It describes how pulmonary hypertension results from endothelial dysfunction, vascular remodeling and thrombosis that increases pulmonary vascular resistance. Clinical assessment involves evaluating symptoms, signs of right heart failure and functional classification. Diagnosis requires tests to identify the underlying cause and severity. Anesthesia poses risks that depend on the disease severity and type of surgery. Careful management of oxygenation, ventilation and hemodynamics is needed in these high-risk patients.
The study evaluated the ability of the third-generation FloTrac/Vigileo device to track changes in cardiac index (CI) induced by volume expansion or changes in norepinephrine dose in critically ill patients. The device showed moderate accuracy in tracking CI changes from volume expansion, but poor reliability for changes from norepinephrine titration. Specifically, changes in CI measured by the device (CIpw) correlated moderately with changes measured by thermodilution (CItd) for volume expansion but correlated poorly for norepinephrine changes. The ability of the device to track CI changes correlated inversely with changes in systemic vascular resistance.
This study examined the relationship between volume overhydration and endothelial dysfunction in 81 stable patients on continuous ambulatory peritoneal dialysis. Volume status was assessed by normalized extracellular water and endothelial function was estimated by flow-mediated dilation of the brachial artery. There was an independent correlation between the index of volume status (normalized extracellular water) and endothelial function (flow-mediated dilation), with higher normalized extracellular water related to worse endothelial function. Multiple regression analysis identified calcium-phosphate product, normalized extracellular water, and dialysis vintage as independent determinants of endothelial function. The results suggest that volume overhydration may lead to increased cardiovascular risk in dialysis patients through its effects on endothelial dysfunction.
The document discusses heart failure (HF), its epidemiology, pathophysiology, and management. Some key points:
- HF is a major public health problem costing $29.6 billion annually in the US. Hospitalizations are a major driver of costs, and rates are increasing.
- Over 90% of acute decompensated HF hospitalizations are due to fluid overload. Diuretics are standard first-line treatment but resistance limits their effectiveness in many patients.
- Even mild reductions in renal function correlate with increased HF morbidity and mortality. Diuretics can further impair renal function, worsening outcomes.
- Ultrafiltration is an alternative fluid removal method that may benefit patients where diure
Sepsis and Early Goal Directed Therapy: Approach in ED outlines sepsis definitions, the theory and components of early goal directed therapy (EGDT) for treating sepsis. EGDT aims to optimize oxygen delivery through fluid resuscitation, vasopressors to maintain blood pressure, scvO2 monitoring and blood transfusions if needed. The document recommends beginning IV antibiotics within 1 hour of recognizing sepsis to improve survival rates. Timely implementation of EGDT's components in the emergency department can help reduce mortality from sepsis.
This document summarizes two studies on percutaneous left ventricular assist devices (LVADs) and coronary artery fistulas.
The first study investigated the ability of a percutaneous LVAD to deliver blood to the systemic circulation during cardiac arrest in pigs. The LVAD maintained blood flow and preferentially perfused vital organs like the brain. Intensified fluid loading further improved LVAD performance.
The second study evaluated the microvascular effects of ultrasound contrast (Definity) in hamsters with conditions like ischemia-reperfusion, diabetes, and sepsis. Inflammatory responses were higher in diabetes with ischemia and sepsis groups, independent of contrast use. Contrast did not alter hemodynamics or reology.
Echocardiographic changes were studied in 20 patients admitted to the ICU in Ouargla, Algeria with acute pulmonary edema (APE) following scorpion envenomation. Echocardiography revealed decreased systolic ejection fraction, regional abnormalities in cardiac kinetics, and mitral regurgitation in half of patients. These findings along with positive responses to dobutamine treatment suggest APE has a cardiogenic etiology from the negative inotropic effects of scorpion toxins. While other mechanisms may also be involved, echocardiography provides evidence that scorpion envenomation-induced APE is primarily caused by cardiac dysfunction, supporting use of inotropic drugs like dobutamine
Teens and young adults are increasingly using electronic cigarettes, but little is known about the long-term cardiopulmonary health effects of these nicotine-delivery devices.
During this webinar, Jason Gardner, PhD, presents his latest findings using a mouse model of chronic, inhaled nicotine exposure. Post-exposure to nicotine caused mice to develop pulmonary hypertension (PH) and right ventricular (RV) remodeling, a phenomenon that is prevented using an angiotensin II type I receptor (AT1) blocker, losartan. Dr. Gardner discusses the details of this work and how the renin-angiotensin system plays a key role in PH and RV remodeling. In addition, he expands upon the current research with new, unpublished findings.
For more information or to watch the webinar, visit https://bit.ly/3guetlr
Stress echocardiography uses ultrasound imaging during physical or pharmacological stress to detect abnormalities in heart wall motion that indicate reduced blood flow to the heart muscle. It can be used to diagnose coronary artery disease, assess heart valve function, and determine heart muscle viability. The document describes different stress techniques, pharmacological agents, protocols, safety, and interpretation of stress echocardiography. Dobutamine stress echocardiography is useful for detecting ischemia and assessing viability while vasodilator stress is better for perfusion imaging. Low dose dobutamine can identify hibernating myocardium through improvement or a biphasic response in segmental wall motion.
This document discusses end tidal carbon dioxide (EtCO2) monitoring for patients with neuromuscular diseases. It provides information on the benefits of CO2 monitoring, the basics of how CO2 monitoring works, different CO2 monitoring devices and their costs, studies that have evaluated the accuracy and clinical applications of CO2 monitoring in various patient populations and clinical settings, and indications that CO2 monitoring can improve outcomes for patients with respiratory conditions.
IOSR Journal of Pharmacy (IOSRPHR), www.iosrphr.org, call for paper, research...iosrphr_editor
This study investigated the effects of oral clonidine premedication on hemodynamic changes during laparoscopic cholecystectomy. 100 patients were randomly assigned to receive either oral clonidine 150 micrograms or ranitidine 150 mg 90 minutes before surgery. Heart rate, blood pressure, and the need for antihypertensive treatment were significantly lower in the clonidine group during and after surgery. Postoperative nausea, vomiting, shivering, pain, and sedation were also reduced with clonidine premedication. The results suggest that oral clonidine can provide hemodynamic stability and reduce postoperative complications for patients undergoing laparoscopic cholecystectomy.
The document provides information on the ES Teck System, which measures heart rate variability (HRV), blood oxygen saturation (SpO2), photoplethysmography, and body impedance analysis (BIA). It analyzes HRV, pulse waves, vascular health, body composition, and provides indicators for various body systems. Results include HRV statistics, SpO2 and photoplethysmography readings, BIA measurements, and cross-analysis of indicators to track health and aid physicians.
The document discusses the ES Teck System, which uses multiple modules to analyze heart rate variability, photoplethysmography, bioimpedance analysis, and other biomarkers. It can evaluate the autonomic nervous system, vascular health, body composition, and indicators related to various body systems. Results are analyzed statistically over time and can provide physicians insights into conditions like ADHD or help monitor treatments for conditions like cardiovascular disease or cirrhosis.
Nitrates and Vericiguat in heart failureAmit Gulati
- Vericiguat is a soluble guanylate cyclase stimulator that was studied in the VICTORIA trial for the treatment of worsening chronic heart failure.
- The VICTORIA trial was a randomized, double-blind, placebo-controlled study that assigned patients with worsening heart failure to vericiguat or placebo in addition to standard heart failure therapies.
- The trial found that vericiguat significantly reduced the risk of the primary composite endpoint of cardiovascular death or heart failure hospitalization compared to placebo in patients with worsening chronic heart failure.
This document summarizes the cardiovascular effects of common inotropes and vasopressors. It describes the mechanisms of action and effects on hemodynamics of catecholamines like dopamine, dobutamine, epinephrine, and norepinephrine. It also discusses the intracellular pathways such as G protein activation and cyclic AMP production that mediate the chronotropic, inotropic, and vasoactive properties of these drugs. The use of inotropes and vasopressors is clinically important for treating conditions like heart failure that compromise cardiac output and vascular tone.
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 provides guidelines for the management of severe sepsis and septic shock according to the Surviving Sepsis Campaign. It outlines the initial resuscitation goals of fluid resuscitation, antibiotic administration, lactate clearance, and maintaining a central venous oxygen saturation of greater than 70% through fluid administration, vasopressors if needed, and dobutamine. The use of stress-dose steroids and recombinant human activated protein C for certain high-risk patients is also recommended.
LCZ696 was more effective than enalapril in reducing the risks of CV death and HF hospitalization, CV death, HF hospitalization, and all-cause mortality in patients with heart failure with reduced ejection fraction. LCZ696 also provided incremental improvements in symptoms and physical limitations. LCZ696 was better tolerated than enalapril with lower rates of symptomatic hypotension, hyperkalemia, renal impairment, and cough.
Linking HFpEF and Chronic kidney disease magdy elmasry
Cardio-renal interactions
Introducing nephro-cardiology
{ or cardio-nephrology }
Where are we in 2022 with HFpEF ?CKD in HFpEF { or HFpEF in CKD } Cardiorenal
Syndrome .Four-step
HFA-PEFF diagnostic algorithm
heterogeneity in patients with HFpEF.Phenotyping HFpEF :
Beyond EF.Management of HFpEF .patients with HF on dialysis
This document summarizes the pathophysiology and anesthetic management considerations for patients with pulmonary hypertension. It describes how pulmonary hypertension results from endothelial dysfunction, vascular remodeling and thrombosis that increases pulmonary vascular resistance. Clinical assessment involves evaluating symptoms, signs of right heart failure and functional classification. Diagnosis requires tests to identify the underlying cause and severity. Anesthesia poses risks that depend on the disease severity and type of surgery. Careful management of oxygenation, ventilation and hemodynamics is needed in these high-risk patients.
The study evaluated the ability of the third-generation FloTrac/Vigileo device to track changes in cardiac index (CI) induced by volume expansion or changes in norepinephrine dose in critically ill patients. The device showed moderate accuracy in tracking CI changes from volume expansion, but poor reliability for changes from norepinephrine titration. Specifically, changes in CI measured by the device (CIpw) correlated moderately with changes measured by thermodilution (CItd) for volume expansion but correlated poorly for norepinephrine changes. The ability of the device to track CI changes correlated inversely with changes in systemic vascular resistance.
This study examined the relationship between volume overhydration and endothelial dysfunction in 81 stable patients on continuous ambulatory peritoneal dialysis. Volume status was assessed by normalized extracellular water and endothelial function was estimated by flow-mediated dilation of the brachial artery. There was an independent correlation between the index of volume status (normalized extracellular water) and endothelial function (flow-mediated dilation), with higher normalized extracellular water related to worse endothelial function. Multiple regression analysis identified calcium-phosphate product, normalized extracellular water, and dialysis vintage as independent determinants of endothelial function. The results suggest that volume overhydration may lead to increased cardiovascular risk in dialysis patients through its effects on endothelial dysfunction.
The document discusses heart failure (HF), its epidemiology, pathophysiology, and management. Some key points:
- HF is a major public health problem costing $29.6 billion annually in the US. Hospitalizations are a major driver of costs, and rates are increasing.
- Over 90% of acute decompensated HF hospitalizations are due to fluid overload. Diuretics are standard first-line treatment but resistance limits their effectiveness in many patients.
- Even mild reductions in renal function correlate with increased HF morbidity and mortality. Diuretics can further impair renal function, worsening outcomes.
- Ultrafiltration is an alternative fluid removal method that may benefit patients where diure
Sepsis and Early Goal Directed Therapy: Approach in ED outlines sepsis definitions, the theory and components of early goal directed therapy (EGDT) for treating sepsis. EGDT aims to optimize oxygen delivery through fluid resuscitation, vasopressors to maintain blood pressure, scvO2 monitoring and blood transfusions if needed. The document recommends beginning IV antibiotics within 1 hour of recognizing sepsis to improve survival rates. Timely implementation of EGDT's components in the emergency department can help reduce mortality from sepsis.
This document summarizes two studies on percutaneous left ventricular assist devices (LVADs) and coronary artery fistulas.
The first study investigated the ability of a percutaneous LVAD to deliver blood to the systemic circulation during cardiac arrest in pigs. The LVAD maintained blood flow and preferentially perfused vital organs like the brain. Intensified fluid loading further improved LVAD performance.
The second study evaluated the microvascular effects of ultrasound contrast (Definity) in hamsters with conditions like ischemia-reperfusion, diabetes, and sepsis. Inflammatory responses were higher in diabetes with ischemia and sepsis groups, independent of contrast use. Contrast did not alter hemodynamics or reology.
Echocardiographic changes were studied in 20 patients admitted to the ICU in Ouargla, Algeria with acute pulmonary edema (APE) following scorpion envenomation. Echocardiography revealed decreased systolic ejection fraction, regional abnormalities in cardiac kinetics, and mitral regurgitation in half of patients. These findings along with positive responses to dobutamine treatment suggest APE has a cardiogenic etiology from the negative inotropic effects of scorpion toxins. While other mechanisms may also be involved, echocardiography provides evidence that scorpion envenomation-induced APE is primarily caused by cardiac dysfunction, supporting use of inotropic drugs like dobutamine
Teens and young adults are increasingly using electronic cigarettes, but little is known about the long-term cardiopulmonary health effects of these nicotine-delivery devices.
During this webinar, Jason Gardner, PhD, presents his latest findings using a mouse model of chronic, inhaled nicotine exposure. Post-exposure to nicotine caused mice to develop pulmonary hypertension (PH) and right ventricular (RV) remodeling, a phenomenon that is prevented using an angiotensin II type I receptor (AT1) blocker, losartan. Dr. Gardner discusses the details of this work and how the renin-angiotensin system plays a key role in PH and RV remodeling. In addition, he expands upon the current research with new, unpublished findings.
For more information or to watch the webinar, visit https://bit.ly/3guetlr
Stress echocardiography uses ultrasound imaging during physical or pharmacological stress to detect abnormalities in heart wall motion that indicate reduced blood flow to the heart muscle. It can be used to diagnose coronary artery disease, assess heart valve function, and determine heart muscle viability. The document describes different stress techniques, pharmacological agents, protocols, safety, and interpretation of stress echocardiography. Dobutamine stress echocardiography is useful for detecting ischemia and assessing viability while vasodilator stress is better for perfusion imaging. Low dose dobutamine can identify hibernating myocardium through improvement or a biphasic response in segmental wall motion.
This document discusses end tidal carbon dioxide (EtCO2) monitoring for patients with neuromuscular diseases. It provides information on the benefits of CO2 monitoring, the basics of how CO2 monitoring works, different CO2 monitoring devices and their costs, studies that have evaluated the accuracy and clinical applications of CO2 monitoring in various patient populations and clinical settings, and indications that CO2 monitoring can improve outcomes for patients with respiratory conditions.
IOSR Journal of Pharmacy (IOSRPHR), www.iosrphr.org, call for paper, research...iosrphr_editor
This study investigated the effects of oral clonidine premedication on hemodynamic changes during laparoscopic cholecystectomy. 100 patients were randomly assigned to receive either oral clonidine 150 micrograms or ranitidine 150 mg 90 minutes before surgery. Heart rate, blood pressure, and the need for antihypertensive treatment were significantly lower in the clonidine group during and after surgery. Postoperative nausea, vomiting, shivering, pain, and sedation were also reduced with clonidine premedication. The results suggest that oral clonidine can provide hemodynamic stability and reduce postoperative complications for patients undergoing laparoscopic cholecystectomy.
The document provides information on the ES Teck System, which measures heart rate variability (HRV), blood oxygen saturation (SpO2), photoplethysmography, and body impedance analysis (BIA). It analyzes HRV, pulse waves, vascular health, body composition, and provides indicators for various body systems. Results include HRV statistics, SpO2 and photoplethysmography readings, BIA measurements, and cross-analysis of indicators to track health and aid physicians.
The document discusses the ES Teck System, which uses multiple modules to analyze heart rate variability, photoplethysmography, bioimpedance analysis, and other biomarkers. It can evaluate the autonomic nervous system, vascular health, body composition, and indicators related to various body systems. Results are analyzed statistically over time and can provide physicians insights into conditions like ADHD or help monitor treatments for conditions like cardiovascular disease or cirrhosis.
Nitrates and Vericiguat in heart failureAmit Gulati
- Vericiguat is a soluble guanylate cyclase stimulator that was studied in the VICTORIA trial for the treatment of worsening chronic heart failure.
- The VICTORIA trial was a randomized, double-blind, placebo-controlled study that assigned patients with worsening heart failure to vericiguat or placebo in addition to standard heart failure therapies.
- The trial found that vericiguat significantly reduced the risk of the primary composite endpoint of cardiovascular death or heart failure hospitalization compared to placebo in patients with worsening chronic heart failure.
This document summarizes the cardiovascular effects of common inotropes and vasopressors. It describes the mechanisms of action and effects on hemodynamics of catecholamines like dopamine, dobutamine, epinephrine, and norepinephrine. It also discusses the intracellular pathways such as G protein activation and cyclic AMP production that mediate the chronotropic, inotropic, and vasoactive properties of these drugs. The use of inotropes and vasopressors is clinically important for treating conditions like heart failure that compromise cardiac output and vascular tone.
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 describes several physiologic data collection products from LD Products including a galvanic skin response device, body composition analyzer, and photoelectrical plethysmography device. It also discusses software for data interpretation and management, as well as telemedicine services. The ES Complex combines multiple technologies into a single device for measuring parameters like heart rate, blood oxygen levels, pulse analysis, and body composition. It enables early diagnosis and management of conditions like metabolic syndrome, diabetes, and cardiovascular disease through non-invasive screening tests.
EIS technology : bioimpedance application in selective serotonin reuptakeES-Teck India
Through the 6 tactile electrodes, a weak DC current is sending alternatively between 2 electrodes with a sequence and the EIS-GS system is recording the electrical conductance of 11 pathways of the human body.
EIS Technology: bioimpedance chronoamperometry in adjunct to screen the prost...ES-Teck India
Through the 6 tactile electrodes, a weak DC current is sending alternatively between 2 electrodes with a sequence and the EIS system is recording the electrical conductance of 11 pathways of the human body.
Summary of clinical investigations es teck complex systemES-Teck India
Summary of the clinical investigations E.S.Teck Complex March, 20, 2010
Summary of Clinical Investigations ES Teck Complex system EIS System in adjunct to Treatments’ monitoring and to diagnosis with the conventional methods
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.
The document summarizes a research article that examines the relationship between parameters derived from the second derivative of finger photoplethysmogram (PPG) signals and pulse wave velocity (PWV), a measure of arterial stiffness. The study found low but significant correlations between the PPG parameters and PWV. While the measures provide related information on arterial properties, they are not equivalent since PWV reflects aortic stiffness passive effects on pressure, while PPG parameters depend on both central and peripheral effects including ventricular ejection. The relationship between PPG and PWV is complex due to different underlying mechanisms assessed and potential sources of error in the non-invasive techniques.
This document provides an overview of pulse oximetry and the oxyhemoglobin dissociation curve. It defines a pulse oximeter, describes how it works by measuring oxygenated and deoxygenated hemoglobin using light wavelengths, and notes that a normal oxygen saturation level is above 95%. The document also discusses the oxyhemoglobin dissociation curve and how shifts can occur, changing the relationship between oxygen in the blood and hemoglobin saturation. Common uses of pulse oximetry and potential limitations/interferences are outlined.
Comparison of Invasive vs Noninvasive Pulse Wave Indices in Detection of Signifi cant Coronary Artery Disease: Can We Use Noninvasive Pulse Wave Indices as Screening Test
1. Pulse wave analysis in historical times was an important part of medical examination but fell out of favor with the introduction of the cuff sphygmomanometer.
2. Modern pulse wave analysis is regaining favor as limitations of the cuff are recognized. Accurate recording and analysis of the arterial pulse is now possible through high-fidelity tonometry and understanding of arterial hemodynamics.
3. Analysis of pulse waveforms can provide clinically important information about ventricular-vascular interaction and disease states like hypertension that was previously only available through invasive methods.
Guidelines heart rate_variability_ft_1996[1]ES-Teck India
Guidelines
Heart rate variability
Standards of measurement, physiological interpretation, and
clinical use
Task Force of The European Society of Cardiology and The North American
Society of Pacing and Electrophysiology (Membership of the Task Force listed in
the Appendix)
Hypertension:Volume 32(2)August 1998pp 365-370
Assessment of Vasoactive Agents and Vascular Aging by the Second Derivative of
Photoplethysmogram Waveform
[Third Workshop On Structure And Function Of Large Arteries: Part Ii]
The document discusses pulse oximetry and oxygen saturation.
[1] A pulse oximeter uses light to determine the percentage of hemoglobin in blood that is saturated with oxygen (SpO2). It also measures pulse rate.
[2] Oxygen is brought into the lungs and transfers to blood in lung capillaries. It is transported throughout the body bound to hemoglobin in red blood cells.
[3] Oxygen saturation measured by a pulse oximeter (SpO2) indicates if sufficient oxygen is being supplied to tissues. Monitoring SpO2 can help assess disease severity and determine need for treatment.
Cerebral Perfusion Response
to Successful Treatment of
Depression With Different
Serotoninergic Agents with antidepressant therapy have been reported in a number of studies.2–4 In contrast, decreases in the ventral anterior cingulate blood flow were found in response to desipramine,5 electroshock therapy,6 and flu-7
This study examined the effects of intracisternally injected serotonin on cerebral blood flow and systemic pressure in cats during winter and summer months. The researchers found that serotonin produced decreases in cerebral blood flow and systemic pressure lasting 60 to 180 minutes after injection. The decreases in blood flow were significantly greater in winter than summer, but decreases in systemic pressure were not different between seasons. Cats exposed to 3 days of darkness before serotonin injection experienced greater decreases in blood flow compared to light-exposed cats, while systemic pressure changes were similar. The findings suggest the photoperiod may affect the sensitivity of cerebral vessels to serotonin in cats.
The role of antioxidant supplement in immune system, neoplastic, and neurodegenerative disorders: a point of view for an assessment
of the risk/benefit profile. Nutritional Journal
Effects of dopamine on
posttraumatic cerebral blood flow, brain edema, and cerebrospinal fluid
glutamate and hypoxanthine concentrations. Critical Care Medicine,
28(12):3792-3798.
Local Advanced Lung Cancer: Artificial Intelligence, Synergetics, Complex Sys...Oleg Kshivets
Overall life span (LS) was 1671.7±1721.6 days and cumulative 5YS reached 62.4%, 10 years – 50.4%, 20 years – 44.6%. 94 LCP lived more than 5 years without cancer (LS=2958.6±1723.6 days), 22 – more than 10 years (LS=5571±1841.8 days). 67 LCP died because of LC (LS=471.9±344 days). AT significantly improved 5YS (68% vs. 53.7%) (P=0.028 by log-rank test). Cox modeling displayed that 5YS of LCP significantly depended on: N0-N12, T3-4, blood cell circuit, cell ratio factors (ratio between cancer cells-CC and blood cells subpopulations), LC cell dynamics, recalcification time, heparin tolerance, prothrombin index, protein, AT, procedure type (P=0.000-0.031). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and N0-12 (rank=1), thrombocytes/CC (rank=2), segmented neutrophils/CC (3), eosinophils/CC (4), erythrocytes/CC (5), healthy cells/CC (6), lymphocytes/CC (7), stick neutrophils/CC (8), leucocytes/CC (9), monocytes/CC (10). Correct prediction of 5YS was 100% by neural networks computing (error=0.000; area under ROC curve=1.0).
share - Lions, tigers, AI and health misinformation, oh my!.pptxTina Purnat
• Pitfalls and pivots needed to use AI effectively in public health
• Evidence-based strategies to address health misinformation effectively
• Building trust with communities online and offline
• Equipping health professionals to address questions, concerns and health misinformation
• Assessing risk and mitigating harm from adverse health narratives in communities, health workforce and health system
Osteoporosis - Definition , Evaluation and Management .pdfJim Jacob Roy
Osteoporosis is an increasing cause of morbidity among the elderly.
In this document , a brief outline of osteoporosis is given , including the risk factors of osteoporosis fractures , the indications for testing bone mineral density and the management of osteoporosis
One health condition that is becoming more common day by day is diabetes.
According to research conducted by the National Family Health Survey of India, diabetic cases show a projection which might increase to 10.4% by 2030.
TEST BANK For Community Health Nursing A Canadian Perspective, 5th Edition by...Donc Test
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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.
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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.
1. Photoplethysmographic assessment of pulse wave reflection: Blunted response to
endothelium-dependent beta 2-adrenergic vasodilation in type II diabetes
mellitus
Philip J. Chowienczyk, Ronan P. Kelly, Helen MacCallum, Sandrine C. Millasseau,
Tomas L. G. Andersson, Raymond G. Gosling, James M. Ritter and Erik E. Änggård
J. Am. Coll. Cardiol. 1999;34;2007-2014
This information is current as of February 22, 2007
The online version of this article, along with updated information and services, is
located on the World Wide Web at:
http://content.onlinejacc.org/cgi/content/full/34/7/2007
Downloaded from content.onlinejacc.org by on February 22, 2007
3. 2008 Chowienczyk et al. JACC Vol. 34, No. 7, 1999
Pulse Wave Reflection in Type II Diabetes Mellitus December 1999:2007–14
influence the DVP in humans and to explore the use of the
Abbreviations and Acronyms DVP in detecting abnormalities in vascular reactivity in
DVP digital volume pulse patients with type II diabetes mellitus, a group known to
GTN glyceryl trinitrate exhibit marked endothelial dysfunction (14 –16). We mea-
IPDVP inflection point in digital volume pulse
sured the effects of local and systemic administration of
expressed as percent DVP amplitude
iv intravenous vasodilators on the DVP, and compared the time interval
LAo distance from the root of the subclavian between components of the DVP with aortic pulse wave
artery to the bifurcation of the aorta transit time (TAo). Aortic pulse wave velocity (PWVAo) was
L-NMMA NG-monomethyl-L-arginine calculated from TAo and aortic length. The PWVAo is an
NO nitric oxide accepted measure of aortic compliance (17,18). We com-
PWVAo aortic pulse wave velocity
sl sublingual pared the effects of vasodilators on DVP, PWVAo and
TAo aortic pulse wave transit time (root of peripheral vascular resistance, and we examined the effects
subclavian artery to aortic bifurcation) of altering wave reflection from the lower body by supra-
TDVP time between first and second peak of systolic leg cuff inflation.
digital volume pulse
Our results suggested that the DVP comprises a direct
component arising from pressure waves propagating from
the heart to the finger and a delayed component arising
from pressure waves reflected backward from peripheral
IPDVP after GTN has been variously attributed to a “Wind- arteries mainly in the lower body, which then propagate to
kessel” effect resulting from increased compliance of large the finger. In further studies IPDVP was used to assess the
arteries and to decreased venous return to the heart (5,7). effects of the beta2-adrenergic agonist albuterol (salbuta-
The pressure pulse has been studied more extensively than mol). We have previously shown that the vasodilator effects
the volume pulse (8), and changes in the pressure pulse of albuterol on forearm resistance arteries are mediated, in
caused by GTN are thought to result mainly from decreased part, through the L-arginine–NO pathway (19). To deter-
pressure wave reflection (9 –11). Although infrared light mine whether the effects of albuterol on the DVP are
transmission through the finger can, in combination with a similarly dependent on this pathway, we performed studies
servocontrolled finger pressure cuff, be used to derive a in the presence and absence of an NO synthase inhibitor,
pressure pulse (12), the DVP obtained by simple photo- NG-monomethyl-L-arginine (L-NMMA). Finally we com-
plethysmography and pressure pulse waveforms differ and pared the effects of albuterol and GTN on the DVP in
their relation is complex (13). Changes in the DVP pro- patients with uncomplicated type II diabetes and healthy
duced by GTN do, however, parallel those in the pressure control subjects.
pulse (13). Decreased pressure wave reflection might there-
fore account for effects of GTN on the DVP. The purpose METHODS
of the present study was to investigate the factors that
Subjects. Healthy volunteers, recruited from the local com-
munity by advertisement, were screened by physical exam-
ination and routine biochemistry. All were normotensive
(office blood pressure 140/90 mm Hg) and none had total
serum cholesterol values 230 mg/dl. Patients with type II
diabetes were recruited from the Diabetic Clinic at St.
Thomas’ Hospital; they were managed by diet or by diet
plus oral hypoglycemic therapy. No patients had complica-
tions other than background diabetic retinopathy, and none
were receiving vasoactive drug therapy. The characteristics
of the subjects participating in the sub-study of the com-
parison of the DVP between patients with type II diabetes
and control subjects are shown in Table 1. Control subjects
in this sub-study were recruited concurrently with patients
with diabetes and were similar in terms of age and gender
distribution. Subjects in all other studies were male volun-
Figure 1. The digital volume pulse (DVP) and first derivative teers. The study was approved by St. Thomas’ Hospital
(dV/dt, lower trace) recorded before and after systemic adminis-
tration of GTN (500 g sublingually). The notch or point of Research Ethics Committee, and all subjects gave written,
inflection at height, b, is identified by the local maximum in the informed consent.
first derivative. The height of the inflection point (IPDVP) is
expressed as percent DVP amplitude, a. The IPDVP falls after Photoplethysmography. A photoplethysmograph (Micro
GTN. The time between the first and second peak of the DVP Medical, Gillingham, Kent, United Kingdom) transmitting
( TDVP) was measured in some experiments. infrared light at 940 nm was placed on the index finger of
Downloaded from content.onlinejacc.org by on February 22, 2007
4. JACC Vol. 34, No. 7, 1999 Chowienczyk et al. 2009
December 1999:2007–14 Pulse Wave Reflection in Type II Diabetes Mellitus
Table 1. Characteristics of Patients With Type II Diabetes Mellitus and Control Subjects
Control Subjects Diabetics
(n 20) (n 20)
Gender (M/F) 15/5 13/7
Smokers/nonsmokers 4/16 5/15
Age (yrs) 44 6.9 48 10
Systolic BP (mm Hg) 123 17 131 21
Diastolic BP (mm Hg) 71 13 78 12
BMI (kg/m2) 24 2.5 28 4.7*
Glucose (mmol/liter) 4.8 0.6 10.3 5.3*
HbA1c (%) 4.9 0.6 7.7 2.0*
Total cholesterol (mg/dl) 189 31 201 46
Triglycerides (mg/dl) 115 71 230 186
HDL cholesterol (mg/dl) 54 12 46 12
*p 0.05 compared with control subjects. Data are presented as mean value SD.
BP blood pressure; BMI body mass index; HbA1c glycogylated hemoglobin; HDL high density lipoprotein.
the right hand (except in experiments involving brachial blood flow (mean of five venous occlusions) measured
artery infusion when bilateral measurements were made). during the last 2 min of each infusion period. The DVP
Frequency response of the photoplethysmograph was flat to recordings were obtained immediately after forearm blood
10 Hz. Digital output from the photoplethysmograph was flow measurements.
recorded through an analogue-to-digital converter (12 bit,
Photoplethysmographic measurements during systemic
sampling frequency 100 Hz). The first derivative with
administration of vasodilators and leg cuff inflation. The
respect to time of the DVP signal was used to identify the
notch or inflection point as the point, after the first peak of DVP recordings were obtained during administration of
the waveform, at which the first derivative was at a local GTN, 500 g sublingual (sl) for 5 min and 10 to
maximum. The IPDVP was taken as the height of this point 100 g/min intravenous (iv) and albuterol 100 to 400 g by
(b) expressed as percent amplitude of the waveform (a): inhalation through a spacer or 2 to 20 g/min iv. During sl
IPDVP b/a 100% (Fig. 1). The IPDVP was calculated administration of GTN, changes in IPDVP were maximal
from the mean of three or more consecutive cycles of the between 3 and 5 min. The mean of measurements over this
DVP. In some experiments the time between the first and period was used to quantify the response to sl GTN. The
second peak of the DVP ( TDVP) (Fig. 1) was measured. response to inhaled albuterol was taken as the mean of
All measurements were made with the subject supine in a measurements at 10 and 15 min after inhalation. This
temperature-controlled laboratory at 26 1°C. All subjects avoided artifactual responses relating to the inhalational
were allowed to acclimatize to this temperature for at least maneuver (assessed using a placebo inhaler), which resolved
30 min before recordings commenced. within 5 min. Responses to iv administration of GTN and
albuterol were measured after the attainment of steady state
Photoplethysmographic measurements during brachial or when responses were maximal. In some experiments
artery infusion of vasodilators. Bilateral DVP and fore- simultaneous measurements of PWVAo, derived from aortic
arm blood flow measurements were made simultaneously transit times as described subsequently, were made before,
during brachial artery administration of albuterol and GTN. during and after administration of GTN and albuterol.
The brachial artery was cannulated using a 27-gauge steel Changes in IPDVP were also measured before and after
needle (Coopers Needleworks, Birmingham, United King- bilateral suprasystolic leg cuff inflation.
dom) using 0.25 ml of 1% lidocaine as local anesthetic.
Drugs diluted in 0.9% saline and saline alone were infused Measurement of TAo: Comparison with TDVP. The TAo
at 1 ml/min. Forearm blood flow was measured in both was measured from the “foot to foot” delay time between
arms by venous occlusion strain gauge plethysmography Doppler velocity sonograms obtained using 4-MHz contin-
(20) electrically calibrated (21). Wrist cuffs were not used so uous wave transducers (Sonicaid, BV 380, Oxford, United
as to include the contribution ( 50%) from the hand to Kingdom). One transducer was placed in the left anterior
total forearm blood flow (22). After baseline measurements triangle of the neck to insonate the root of the left
during infusion of saline alone, the DVP and blood flow subclavian artery and the other at the midpoint between the
were measured during infusions of four cumulative doses anterior superior iliac spines to insonate the abdominal aorta
(0.1, 0.3, 1.0 and 3.0 g/min) of albuterol (Allen and just above the aortic bifurcation. Real-time spectral analysis
Hanburys, United Kingdom) or four cumulative doses of was used to obtain the maximal frequency envelopes of the
GTN (0.1, 0.3, 1.0 and 3.0 g/min) (David Bull Labora- Doppler signals and the “foot to foot” transit time between
tories, Australia). Each dose was infused for 5 min with these obtained as previously described (23). The distance
Downloaded from content.onlinejacc.org by on February 22, 2007
5. 2010 Chowienczyk et al. JACC Vol. 34, No. 7, 1999
Pulse Wave Reflection in Type II Diabetes Mellitus December 1999:2007–14
from the root of the subclavian artery to the bifurcation of noninfused arm. Brachial artery infusion of albuterol in-
the aorta (LAo) was measured from surface markings (24). creased the amplitude of the DVP waveform but produced
The PWVAo was calculated from LAo/TAo (23). This no significant change in IPDVP in the infused or noninfused
method is similar to that described by Avolio et al. (17,18). arm. The ratio of forearm blood flow in the infused to
The TAo was compared with the TDVP. In two subjects noninfused arm increased more than threefold, while the
the second peak of the DVP was not clearly defined, and in ratio of the IPDVP in the infused to noninfused arm
these subjects the first derivative was used to identify the remained constant to within 10% (p 0.001 for compari-
time of the second peak. son of blood flow ratio and IPDVP ratio) (Fig. 2). Brachial
artery infusion of GTN (0.1 to 3 g/min) increased forearm
Effects of L-NMMA on the DVP response to albuterol
blood flow in the infused arm from 9.8 2.0 to 22.4
and GTN. The IPDVP response to albuterol (400 g by
2.4 ml/min per 100 ml (p 0.01) but had no significant
inhalation) was assessed 15 min after administration of
effect on forearm blood flow in the noninfused arm. Brachial
L-NMMA (3 mg/kg IV over 5 min), and on another
artery infusion of GTN was associated with a small but
occasion, separated by at least one week, after saline placebo
significant fall in IPDVP of the infused arm (60 5.5% to
in a two-phase randomized crossover study. We and other
53 5.8%, p 0.05), but IPDVP of the noninfused arm fell
investigators have previously established that the response to
to a similar degree (63 5.1% to 49 6.3%) so that the
this dose of L-NMMA is maximal at 15 min (25,26). The
ratio of the IPDVP in the infused to noninfused arm
response to GTN (500 g sl) was measured after the same
remained constant (p 0.001 for comparison of blood flow
dose of L-NMMA and saline placebo in the same study
ratio and IPDVP ratio) (Fig. 2).
design. In addition to IPDVP, mean arterial blood pressure
(Dinamap model 1846 SX, Critikon, Florida) and cardiac Systemic administration of vasodilators and leg cuff
output (bioimpedance cardiac output monitor: BoMed inflation. Albuterol (100 to 400 g by inhalation and 25 to
NCCOM3, BoMed Medical Manufacturing Ltd, Califor- 100 g iv bolus and 2 to 20 g/min iv) and GTN (500 g
nia) were measured noninvasively using previously validated sl and 10 to 100 g/min iv) reduced IPDVP (Fig. 3).
methods (27,28). Total systemic vascular resistance was Changes from baseline in IPDVP and in systemic hemody-
estimated by dividing mean arterial pressure by cardiac namic values after albuterol (400 g by inhalation) and
output. All measurements were made with subjects supine. GTN (500 g sl) in 10 healthy volunteers are shown in
Figure 4. Reductions in IPDVP of 16.8 3.2% (26.2
DVP responses in patients with type II diabetes and
5.7% change from baseline) and 24.0 1.9% (40.4 4.2%
control subjects. After 30 min rest supine basal measure-
change from baseline) after albuterol and GTN, respec-
ments of IPDVP, pulse rate and blood pressure were ob-
tively, were accompanied by relatively minor changes in
tained at 5 min intervals for 15 min. Glyceryl trinitrate
heart rate (increase of 12.9 2.9 and 6.4 2.3 beats/min
(500 g sl) was then administered and measurements
for albuterol and GTN, respectively, each p 0.05) and
obtained at 1-min intervals for 5 min and at 5-min intervals
blood pressure (changes in systolic blood pressure of 5.1
for 30 min, by which time all hemodynamic values had
2.7 and 4.0 3.0 mm Hg, each p NS, and decreases
returned to baseline. Albuterol (400 g by inhalation
in diastolic blood pressure of 3.2 1.8 mm Hg [p NS]
through spacer) was given and further measurements were
and 4.9 1.6 mm Hg [p 0.05] for albuterol and GTN,
made at 5-min intervals for 20 min. Responses to GTN and
respectively). Systemic vascular resistance fell by 26 3.6%
albuterol were assessed as described earlier.
and 16 3.4% and cardiac output increased by 30 5.5%
Statistics. Subject characteristics are presented as the mean and 8.2 3.1% (each p 0.05) after albuterol and GTN,
value SD. Results are presented as the mean value SE. respectively. In experiments where PWVAo and IPDVP were
Analysis of variance for repeated measures was used to test
for differences in IPDVP and other hemodynamic measure-
ments. The Mann-Whitney U test was used to test for
differences in IPDVP response between patients with dia-
betes and control subjects. Correlation between TAo and
TDVP was sought using least squares regression analysis.
Differences were considered significant at p 0.05 (two-
tailed).
RESULTS
Brachial artery infusion of vasodilators. Brachial artery
infusion of albuterol (0.1 to 3 g/min) increased total blood
Figure 2. Ratios of forearm blood flow (FBF, open squares) and
flow in the infused arm from 4.9 0.7 ml/min per 100 ml inflection point of the digital volume pulse (IPDVP, circles) in the
forearm to 24.5 3.3 ml/min per 100 ml (p 0.001), but infused-noninfused arms during brachial artery infusion of albu-
had no significant effect on forearm blood flow in the terol (ALB, n 5) and glyceryl trinitrate (GTN, n 5).
Downloaded from content.onlinejacc.org by on February 22, 2007
6. JACC Vol. 34, No. 7, 1999 Chowienczyk et al. 2011
December 1999:2007–14 Pulse Wave Reflection in Type II Diabetes Mellitus
Figure 3. Typical DVP traces showing responses to sublingual (s.l.) and intravenous (i.v.) and to inhaled and i.v. albuterol (ALB).
measured simultaneously, changes in IPDVP after adminis-
tration of albuterol or GTN were not accompanied by
significant changes in PWVAo (Fig. 5). Bilateral suprasys-
tolic leg cuff inflation increased IPDVP by 13.3 2.5% (n
9, p 0.01).
Comparison of TDVP with TAo. The TDVP was corre-
lated with TAo—the delay between the foot of the velocity
sonogram at the subclavian artery and that at the aortic
bifurcation (r 0.75, n 20, p 0.0001) (Fig. 6). The
slope of the regression line was 3.9 0.81.
Effect of L-NMMA on DVP response to albuterol and
GTN. Changes in IPDVP in response to albuterol were less
when albuterol was administered after L-NMMA as com-
pared with saline placebo (5.4 7.5% change from baseline
for albuterol after L-NMMA vs. 26 5.7% change from
baseline for albuterol after saline, n 10, p 0.01) (Fig. 4).
In contrast, changes in IPDVP after GTN were similar after
L-NMMA and saline placebo (37.2 6.4% change from
baseline for GTN after L-NMMA vs. 40.4 4.2% change
from baseline for GTN after saline, n 10, p 0.68)
(Fig. 4). The increase in cardiac output after both GTN Figure 4. Changes from baseline in hemodynamic measurements
and albuterol was significantly less after L-NMMA than after GTN (n 10) and albuterol (ALB, n 10) after saline
placebo or L-NMMA administered 15 min before GTN/ALB.
after saline placebo (each p 0.05). Changes in other CO cardiac output; DBP diastolic blood pressure; HR
hemodynamic values after albuterol and GTN did not heart rate; IPDVP height of inflection point of DVP measured as
differ significantly according to whether L-NMMA or percent amplitude; SBP systolic blood pressure; SVR sys-
saline had been administered, although there was a temic vascular resistance. Percent change from baseline of the
IPDVP refers to change in percent units (e.g., fall from 80% to 60%
tendency for the fall in systemic vascular resistance after [80 – 60]/80 25%). *p 0.05 for L-NMMA vs. saline. **p
albuterol to be less after L-NMMA than after saline 0.01 for L-NMMA vs. saline. Open box saline; dotted box
placebo (p 0.09). L-NMMA.
Downloaded from content.onlinejacc.org by on February 22, 2007
7. 2012 Chowienczyk et al. JACC Vol. 34, No. 7, 1999
Pulse Wave Reflection in Type II Diabetes Mellitus December 1999:2007–14
Table 2. Changes in Heart Rate and Blood Pressure After
Albuterol and Glyceryl Trinitrate in Patients With Type II
Diabetes Mellitus and Control Subjects
Control Subjects Diabetics
(n 20) (n 20)
Heart rate (beats/min)
ALB 9.8 1.6* 7.1 1.2*
GTN 6.5 1.2* 5.6 1.2*
Systolic BP (mm Hg)
ALB 0.3 3.0 1.6 3.1
GTN 2.7 1.9 5.4 2.1
Diastolic BP (mm Hg)
ALB 2.0 2.3 6.4 2.6
GTN 6.1 1.4* 6.7 1.4*
*p 0.05 compared with zero. Data are presented as mean value SD.
ALB albuterol; BP blood pressure; GTN glyceryl trinitrate.
test) (Fig. 7). Overall, in all subjects and for both drugs,
there was no correlation between the change in IPDVP and
the change in heart rate (r 0.26, p 0.24). At the doses
used, GTN produced a greater fall in IPDVP than did
albuterol (p 0.0001), despite a less marked increase in
heart rate.
Figure 5. Height of the inflection point of the digital volume pulse
relative to the amplitude (IPDVP) and aortic pulse wave velocity
(PWVAo) in healthy men (n 5) at baseline, 5 min after GTN DISCUSSION
(500 g sublingually) and after 20 min of recovery.
Photoplethysmography. Photoplethysmography provides
a simple means for deriving the DVP. Although widely used
DVP responses to albuterol and GTN in patients with as a means for displaying the pulse (for example, in pulse
type II diabetes. The effects of albuterol and GTN on oximetry), its use to study the detail of the shape of the
heart rate and blood pressure were similar in control subjects waveform itself has received surprisingly little attention.
and patients with type II diabetes (Table 2). At baseline This may be because the peripheral site of recording and the
IPDVP was similar in patients with type II diabetes and difference between the DVP and arterial pressure waveform
control subjects. The fall in IPDVP in response to GTN was give the misleading impression that the DVP is influenced
similar in diabetic patients and control subjects (18.3 mainly by local factors. However, Takazawa et al. (6) have
1.2% vs. 18.6 1.9%, n 20, p 0.88). The response to shown that the second derivative of the DVP may be used to
albuterol in patients with diabetes was significantly less than
that in control subjects (5.9 1.8% vs. 11.8 1.8%, n
20, p 0.02 by analysis of variance and Mann-Whitney U
Figure 7. Decrease from baseline in the height of the inflection
Figure 6. Correlation between the time from the first to second point of the digital volume pulse (IPDVP) after GTN (500 g
peak of the digital volume pulse ( TDVP) and pressure wave transit sublingually) and albuterol (ALB, 400 g by inhalation through
time from the root of the subclavian artery to the aortic bifurcation spacer) in patients with type II diabetes (n 20) and control
(TAo) in 20 healthy men (r 0.75, p 0.0001). subjects (n 20).
Downloaded from content.onlinejacc.org by on February 22, 2007
8. JACC Vol. 34, No. 7, 1999 Chowienczyk et al. 2013
December 1999:2007–14 Pulse Wave Reflection in Type II Diabetes Mellitus
infer changes in the systemic circulation relating to the effects from the foot to foot delay between direct and reflected waves.
of drugs and aging. In the present study, we have focused on Our observation that TDVP is approximately four times the
IPDVP—the relative height of the inflection point separating TAo is nevertheless compatible with the suggestion by Yagi-
the systolic and diastolic components of the DVP. numa et al. (10), Latson et al. (29) and others (8) that wave
reflection occurs predominantly from small arteries in the trunk
Lack of effect of local vasodilation on IPDVP. We found
and lower limbs. Because large changes in DVP pulse are
that direct infusion of vasodilators into the brachial artery
observed in response to GTN in the absence of large changes
sufficient to increase total forearm blood flow more than
in systemic vascular resistance, such arteries must be proximal
threefold had little or no effect on IPDVP. The highest dose
to resistance vessels.
of GTN was associated with a small but significant effect on
the IPDVP, but this was similar in the infused and nonin- Influence on IPDVP of systolic ejection time, heart rate
fused arms, suggesting that it was due to a systemic rather and pulse wave velocity. Systolic ejection time and heart
than local effect. In contrast, systemic administration of rate are likely to influence IPDVP (8). However, in the
GTN produced a profound change in IPDVP while having present study we found no correlation between the change
no significant effect on forearm blood flow. These observa- in IPDVP and the change in heart rate. Furthermore,
tions effectively exclude local circulatory changes in the arm compared with albuterol, GTN produced less increase in
or hand (which contributes 50% to forearm blood flow heart rate and cardiac output but a greater fall in IPDVP.
[22]) as responsible for effects of systemic administration of This suggests that the effects of these drugs on IPDVP occur
albuterol or GTN on IPDVP in normal subjects at an independently of any effect on heart rate. A change in IPDVP
ambient temperature of 26°C. could occur as a result of vasodilation of the arteries, which
contributes most to wave reflection, thus reducing the
Influence of wave reflection. Of the various explanations
reflected waves as well as IPDVP. Alternatively, decreased
that have been suggested to account for the IPDVP that which
aortic pulse wave velocity, resulting from increased aortic
best fits our observations is that the DVP is determined by
and large artery compliance (17,18), could delay arrival of
direct and reflected pressure waves. Reflected waves arising
the reflected wave relative to the direct wave, increasing
mainly from the lower body are delayed relative to the direct
TDVP and hence reducing IPDVP. To distinguish between
wave, and therefore produce an inflection point or second peak
these possibilities we made simultaneous measurements of
in the DVP. O’Rourke et al. (8,9) have previously suggested
PWVAo and IPDVP during administration of vasodilators.
that systemic administration of GTN reduces pressure wave
We found that changes in IPDVP were not accompanied by
reflection, and this is consistent with the reduction of IPDVP
changes in PWVAo. This is consistent with the observations
seen after systemic but not local administration of GTN in the
of Yaginuma et al. (10), who found GTN to have no effect
present study. Suprasystolic pressure cuff inflation around the
on the timing of vascular reflections. This suggests that
thighs would be expected to increase pressure wave reflection
during vasodilator therapy, a reduction in IPDVP is due
from the legs, and indeed this was accompanied by an increase
mainly to dilation of small arteries reducing wave reflection
in IPDVP, supporting the concept of the IPDVP being influ-
from the lower body.
enced by wave reflection. Further evidence of wave reflection
determining the characteristics of the DVP arises from the Effect of albuterol on IPDVP as a test of endothelial
correlation between TDVP and TAo: if the second peak of the function. Vasodilator effects of GTN are mediated
DVP is caused by pressure waves reflected from peripheral through its metabolism in vascular smooth muscle to NO or
arteries, then the TDVP of the DVP waveform would be a nitrosothiol (30). Vasodilators that stimulate NO release
expected to be related to the time taken for pressure waves to from the endothelium through the L-arginine–NO pathway
pass from the heart to the “site of reflection” and back to the might therefore be expected to have a similar effect on
heart (the transit times for pressure waves to pass from the IPDVP to GTN. In the present study we found that
heart to the subclavian artery and from the subclavian artery albuterol produced a marked change in IPDVP. We and
along the arm to the finger being common for both the direct other investigators have previously shown that beta-
and reflected waves). We observed a strong correlation be- adrenergic agonists—albuterol, in particular—produce va-
tween TDVP and the propagation time of pressure waves sodilation in resistance arteries, which is dependent on the
along the aorta from the TAo. This correlation again supports L-arginine–NO pathway (19,31). To determine whether
the concept of wave reflection as a major determinant of the effects of albuterol on the IPDVP are mediated through
IPDVP. Reflections from many sites within the vascular tree are the L-arginine–NO pathway, we examined responses to
likely to contribute to the reflected wave seen at the periphery, albuterol in the presence and absence of L-NMMA. We
resulting in temporal spread of the reflected wave. The time also examined the effects of L-NMMA on GTN as a
between the peak of the direct wave and the peak of the control study. L-NMMA blunted the effect of albuterol on
reflected wave cannot, therefore, be used to define precisely the IPDVP but did not influence the effect of GTN. This
time taken for pressure waves to pass from sites of reflection to suggests that the effect of albuterol on IPDVP is mediated at
the upper limb, because there are multiple such sites and least in part through the L-arginine–NO pathway.
because such timing information would need to be inferred The finding that the IPDVP response to albuterol depends
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9. 2014 Chowienczyk et al. JACC Vol. 34, No. 7, 1999
Pulse Wave Reflection in Type II Diabetes Mellitus December 1999:2007–14
on the endothelial L-arginine–NO pathway raises the pos- on peripheral arteries alters left ventricular hydraulic load in man.
Cardiovasc Res 1986;20:153– 60.
sibility that this response may be used to examine the 11. Kelly RP, Gibbs HH, O’Rourke MF, et al. Nitroglycerin has more
integrity of this pathway in conditions associated with favourable effects on left ventricular afterload than apparent from
endothelial dysfunction. To investigate this, we examined measurement of pressure in a peripheral artery. Eur Heart J 1990;11:
the response to albuterol (and GTN as an endothelium- 138 – 44.
12. Imholz BP, Wieling W, van Montfrans GA, Wesseling KH. Fifteen
independent control) in patients with type II diabetes. We years experience with finger arterial pressure monitoring: assessment of
chose this group because there is evidence of marked the technology. Cardiovasc Res 1998;38:605–16.
impairment of endothelium-dependent vasodilation in such 13. Millasseau SC, Bland JE, Kelly RP, et al. Comparison of effects of
GTN on the digital volume and radial pressure pulse waveforms
patients (14 –16). We found that responses to albuterol in (abstr). Br J Clin Pharmacol 1999;16:2218.
type II diabetic patients are indeed blunted relative to 14. McVeigh GE, Brennan GM, Johnston GD, et al. Impaired
nondiabetic control subjects, whereas responses to GTN are endothelium-dependent and independent vasodilation in patients with
type 2 (non–insulin-dependent) diabetes mellitus. Diabetologia 1992;
preserved, consistent with a defect in the endothelial L- 35:771– 6.
arginine–NO pathway in type II diabetes. These findings 15. Williams SB, Cusco JA, Roddy MA, et al. Impaired nitric oxide–
therefore suggest that the IPDVP response to albuterol may mediated vasodilation in patients with non–insulin-dependent diabetes
mellitus. J Am Coll Cardiol 1996;27:567–74.
be used as a simple test of endothelial function. Its appli- 16. Watts GF, O’Brien SF, Silvester W, Millar JA. Impaired
cation for this will require further validation, however. endothelium-dependent and independent dilation of forearm resis-
tance arteries in men with diet treated non–insulin-dependent diabe-
Conclusions. Our results suggest that IPDVP is influenced tes: role of dyslipidaemia. Clin Sci 1996;91:567–73.
by wave reflection from the lower body. Glyceryl trinitrate 17. Avolio AP, Chen SG, Wang RP, et al. Effects of aging on changing
and albuterol lower IPDVP through vasodilation of arteries arterial compliance and left ventricular load in a northern Chinese
urban community. Circulation 1983;68:50 – 8.
in the lower body. The effects of albuterol are mediated in 18. Avolio AP, Deng FQ, Li WQ, et al. Effects of aging on arterial
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Department of Clinical Pharmacology, St. Thomas’ Hospital, 21. Hokanson DE, Sumner DS, Strandness DE Jr. An electrically
Lambeth Palace Road, London SE1 7EH, United Kingdom. calibrated plethysmograph for direct measurement of limb blood flow.
E-mail: p.chowienczyk@umds.ac.uk IEEE Trans Biomed Eng 1975;22:25–9.
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10. Photoplethysmographic assessment of pulse wave reflection: Blunted response to
endothelium-dependent beta 2-adrenergic vasodilation in type II diabetes
mellitus
Philip J. Chowienczyk, Ronan P. Kelly, Helen MacCallum, Sandrine C. Millasseau,
Tomas L. G. Andersson, Raymond G. Gosling, James M. Ritter and Erik E. Änggård
J. Am. Coll. Cardiol. 1999;34;2007-2014
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