The early stages of heart development: insights from chicken embryos
... musculus and the chicken Gallus gallus. All of these have different advantages and have made significant contributions to our understanding of developmental processes. The focus of this review will be the chicken, specifically its ...
... musculus and the chicken Gallus gallus. All of these have different advantages and have made significant contributions to our understanding of developmental processes. The focus of this review will be the chicken, specifically its ...
Gene- and cell-based bio-artificial pacemaker: what basic
... cardiac muscle CMs is due to the absence of If and the intense expression of IK1 (a.k.a. the inward-rectifier K+ current), encoded by the Kir2 gene family, which stabilizes a negative resting membrane potential (RMPB 80 mV). Given the limitations of electronic pacemakers, several gene- and cell-base ...
... cardiac muscle CMs is due to the absence of If and the intense expression of IK1 (a.k.a. the inward-rectifier K+ current), encoded by the Kir2 gene family, which stabilizes a negative resting membrane potential (RMPB 80 mV). Given the limitations of electronic pacemakers, several gene- and cell-base ...
β-Adrenergic Signaling in the Heart: Dual Coupling of the
... βAR stimulation is to increase cardiac contractility (positive inotropic effect), accelerate cardiac relaxation (positive lusitropic effect), and increase heart rate (positive chronotropic effect). However, in adult rat ventricular myocytes, although stimulation of both βAR subtypes increases the am ...
... βAR stimulation is to increase cardiac contractility (positive inotropic effect), accelerate cardiac relaxation (positive lusitropic effect), and increase heart rate (positive chronotropic effect). However, in adult rat ventricular myocytes, although stimulation of both βAR subtypes increases the am ...
Heart Rate Variability Anatomy and Physiology
... In a healthy heart, the SA node initiates each cardiac cycle through spontaneous depolarization of its autorhythmic fibers. The SA node’s firing of about 100 action potentials per minute usually prevents slower parts of the conduction system and myocardium (heart muscle) from generating competing po ...
... In a healthy heart, the SA node initiates each cardiac cycle through spontaneous depolarization of its autorhythmic fibers. The SA node’s firing of about 100 action potentials per minute usually prevents slower parts of the conduction system and myocardium (heart muscle) from generating competing po ...
Troponin I, cardiac diastolic dysfunction and restrictive
... Some case reports have described familial restrictive cardiomyopathy in human[63,64]. Both autosomal dominate and autosomal recessive patterns of inherited RCM have been described[65,66]. Very recently, the clinical features of RCM were described as a marked elevation of left ventricular end-diastol ...
... Some case reports have described familial restrictive cardiomyopathy in human[63,64]. Both autosomal dominate and autosomal recessive patterns of inherited RCM have been described[65,66]. Very recently, the clinical features of RCM were described as a marked elevation of left ventricular end-diastol ...
Ventricular long axis function: amplitudes and timings
... regional systolic and diastolic function. Left ventricular (LV) long axis amplitude of motion, referred to as mitral valve annular (MA) motion, is reduced in CAD and to some extent in the elderly as part of the normal ageing process. Objectives & Methods: The aim of the present study was two-fold. F ...
... regional systolic and diastolic function. Left ventricular (LV) long axis amplitude of motion, referred to as mitral valve annular (MA) motion, is reduced in CAD and to some extent in the elderly as part of the normal ageing process. Objectives & Methods: The aim of the present study was two-fold. F ...
Three-Dimensional Cardiac Electrical Imaging From Intracavity
... number of locations within the myocardium ( maybe current density or maybe some other biophysical quantities). Based on the CT images of a human subject, a finite-element (FE) model was built to simulate the realistic geometry thorax volume conductor. The CT images were segmented, edge-detected, and ...
... number of locations within the myocardium ( maybe current density or maybe some other biophysical quantities). Based on the CT images of a human subject, a finite-element (FE) model was built to simulate the realistic geometry thorax volume conductor. The CT images were segmented, edge-detected, and ...
Coronary Artery Disease and Dysrhythmias
... The presence of risk factors appears to accelerate the atherogenesis, decreasing the oxygen supply. The presence of risk factors can also increase the myocardium’s demand for oxygen (see Table 29-1). Concomitant conditions such as anemia, smoking (carbon monoxide displaces oxygen in the bloodstream) ...
... The presence of risk factors appears to accelerate the atherogenesis, decreasing the oxygen supply. The presence of risk factors can also increase the myocardium’s demand for oxygen (see Table 29-1). Concomitant conditions such as anemia, smoking (carbon monoxide displaces oxygen in the bloodstream) ...
Bradycardia Secondary to Cervical Spinal Cord Injury
... placement of a pacemaker are not well defined. The reported number of SCI patients requiring a pacemaker varies from 9 to 17% (Abd & Braun, 1989; Lehmann et al, 1987). Complications of permanent pacemakers include infection, lead malfunction, death during attempted insertion, and death associated wi ...
... placement of a pacemaker are not well defined. The reported number of SCI patients requiring a pacemaker varies from 9 to 17% (Abd & Braun, 1989; Lehmann et al, 1987). Complications of permanent pacemakers include infection, lead malfunction, death during attempted insertion, and death associated wi ...
Prognostic value of the ECG on admission embolism
... mortality. In addition, there appeared to be a tendency towards a correlation between a pathological ECG and the dysfunction (dilatation) of the right ventricle on the initial echocardiogram. Overall, 78% of the current patients who exhibited at least one of the ECG findings mentioned previously als ...
... mortality. In addition, there appeared to be a tendency towards a correlation between a pathological ECG and the dysfunction (dilatation) of the right ventricle on the initial echocardiogram. Overall, 78% of the current patients who exhibited at least one of the ECG findings mentioned previously als ...
Chessboard of atrial fibrillation: reentry or focus? Single or multiple
... refractory period and the conduction velocity of an impulse. Allessie et al. (1) presented compelling evidence in support of a “leading circle” hypothesis, which is based on the wavelength theory. They showed that the reentrant circuit cannot be shorter than the wavelength (22). Yet again, recently, ...
... refractory period and the conduction velocity of an impulse. Allessie et al. (1) presented compelling evidence in support of a “leading circle” hypothesis, which is based on the wavelength theory. They showed that the reentrant circuit cannot be shorter than the wavelength (22). Yet again, recently, ...
CHAPTER ONE THE HEART ANATOMY AND PHYSIOLOGY 2
... series of waves and deflections recording the heart’s electrical activity from a certain “view.” Many views, each called a lead, monitor voltage changes between electrodes placed in different positions on the body. Leads I, II, and III are bipolar leads, which consist of two electrodes of opposite p ...
... series of waves and deflections recording the heart’s electrical activity from a certain “view.” Many views, each called a lead, monitor voltage changes between electrodes placed in different positions on the body. Leads I, II, and III are bipolar leads, which consist of two electrodes of opposite p ...
Use and Outcomes of Triple Therapy Among Older Patients With
... PCI patients recommend treatment with dual anti- ...
... PCI patients recommend treatment with dual anti- ...
Post-traumatic Wolff-Parkinson-White syndrome
... Abstract: The ventricular pre-excitation syndrome (Wolff-Parkinson-White syndrome) is defined as a premature activation of the entire ventricular myocardium by a super-ventricular impulse. The premature activation is made by accessory conduction pathways that produce a short circuit in the normal no ...
... Abstract: The ventricular pre-excitation syndrome (Wolff-Parkinson-White syndrome) is defined as a premature activation of the entire ventricular myocardium by a super-ventricular impulse. The premature activation is made by accessory conduction pathways that produce a short circuit in the normal no ...
BUSTING THROUGH THE 5 MYTHS ABOUT SUDDEN CARDIAC
... Sudden Cardiac Arrest Prevention and Treatment: Strengthening the Chain of Survival ...
... Sudden Cardiac Arrest Prevention and Treatment: Strengthening the Chain of Survival ...
Endothelial Dysfunction
... hyperemia peripheral arterial tonometry. Endothelial dysfunction (defined by a reactive hyperemia index below the median value of 0.49) was independently associated with HFPEF, as were higher body mass index and lower glomerular filtration rate. In HFPEF, endothelial dysfunction predicted cardiovasc ...
... hyperemia peripheral arterial tonometry. Endothelial dysfunction (defined by a reactive hyperemia index below the median value of 0.49) was independently associated with HFPEF, as were higher body mass index and lower glomerular filtration rate. In HFPEF, endothelial dysfunction predicted cardiovasc ...
Postoperative Atrial Fibrillation Following Open Cardiac Surgery
... Smoking was also a predictor of POAF in this study and some of these smoker patients may have COPD, therefore these patients usually have a ventilation perfusion (V/Q) mismatch that can lead to arterial hypoxemia. V/Q mismatch can be aggravated after operation because of poor ventilating mechanics a ...
... Smoking was also a predictor of POAF in this study and some of these smoker patients may have COPD, therefore these patients usually have a ventilation perfusion (V/Q) mismatch that can lead to arterial hypoxemia. V/Q mismatch can be aggravated after operation because of poor ventilating mechanics a ...
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... percutaneous puncture of the left or right femoral vein, a 5 or 6F introducer was placed. Using a multipurpose catheter, the ASD was crossed and positioned in the left upper pulmonary vein. Stiff guide wire was passed and through it a balloon catheter of a size corresponding to the size of the defec ...
... percutaneous puncture of the left or right femoral vein, a 5 or 6F introducer was placed. Using a multipurpose catheter, the ASD was crossed and positioned in the left upper pulmonary vein. Stiff guide wire was passed and through it a balloon catheter of a size corresponding to the size of the defec ...
Left atrial strain in patients with arterial hypertension
... diastolic dysfunction and no hypertrophy; HR, Heart rate; BMI, body mass index; NYHA, New York Heart Association. Blood pressure (BP) was measured ar the end of the echocardiographic examination. * p < 0.001 for patients vs healthy controls. ...
... diastolic dysfunction and no hypertrophy; HR, Heart rate; BMI, body mass index; NYHA, New York Heart Association. Blood pressure (BP) was measured ar the end of the echocardiographic examination. * p < 0.001 for patients vs healthy controls. ...
Module 1 : Basic ECG Interpretation Module 1 Office 97
... their position in the triangle. The following picture shows how the ECG machine changes the charges to show different leads. But the physical position of the white red and black leads does ...
... their position in the triangle. The following picture shows how the ECG machine changes the charges to show different leads. But the physical position of the white red and black leads does ...
Correspondence: Atrial Flutter with 1:1 response
... To the Editor: I enjoyed reading the comments of Dr. Dormois concerning the tracing showing atrial flutter with a 1:1 AV response. Once one goes through the preliminary analysis for supraventricular tachycardias, as reviewed by Dr. Dormois, one makes a decision based on the rate in this arrhythmia. ...
... To the Editor: I enjoyed reading the comments of Dr. Dormois concerning the tracing showing atrial flutter with a 1:1 AV response. Once one goes through the preliminary analysis for supraventricular tachycardias, as reviewed by Dr. Dormois, one makes a decision based on the rate in this arrhythmia. ...
Electrical Axis - Grand County EMS
... which the ECG detects is called the mean vector. • The direction of the mean vector is called the mean electrical axis. • When the electrical current traveling through the heart is moving toward a positive ECG electrode on a person’s chest or extremity the ECG machine records it as a positive or u ...
... which the ECG detects is called the mean vector. • The direction of the mean vector is called the mean electrical axis. • When the electrical current traveling through the heart is moving toward a positive ECG electrode on a person’s chest or extremity the ECG machine records it as a positive or u ...
HCM_03 (Natural history)
... A. In series published in 1980s, annual mortality of patients with HCM in referral center populations was 4 to 6% per year. However, lower annual mortality rates have been observed in more recent series from large unselected HCM patient populations (approximately 1% per year). In report from referra ...
... A. In series published in 1980s, annual mortality of patients with HCM in referral center populations was 4 to 6% per year. However, lower annual mortality rates have been observed in more recent series from large unselected HCM patient populations (approximately 1% per year). In report from referra ...
Changes of natriuretic peptides concentration in early phase of
... myocardial infarction showed that the average age and gender structure were similar with those reported in recent literature (18). It is necessary to note that males were more vulnerable for myocardial infarction than females. But in analyses of the followed parameters known as risk factors for myoc ...
... myocardial infarction showed that the average age and gender structure were similar with those reported in recent literature (18). It is necessary to note that males were more vulnerable for myocardial infarction than females. But in analyses of the followed parameters known as risk factors for myoc ...
Cardiac contractility modulation
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Cardiac contractility modulation (CCM) is a treatment for patients with moderate to severe left ventricular systolic heart failure (NYHA class II–IV). The short- and long-term use of this therapy enhances both the strength of ventricular contraction and the heart’s pumping capacity. The CCM mechanism is based on stimulation of the cardiac muscle by non-excitatory electrical signals (NES). CCM treatment is delivered by a pacemaker-like device that applies the NES, adjusted to and synchronized with the electrical action in the cardiac cycle.In CCM therapy, electrical stimulation is applied to the cardiac muscle during the absolute refractory period. In this phase of the cardiac cycle, electrical signals cannot trigger new cardiac muscle contractions, hence this type of stimulation is known as a non-excitatory stimulation. However, the electrical CCM signals increase the influx of calcium ions into the cardiac muscle cells (cardiomyocytes). In contrast to other electrical stimulation treatments for heart failure, such as pacemaker therapy or implantable cardioverter defibrillators (ICD), CCM does not affect the cardiac rhythm directly. Rather, the aim is to enhance the heart’s natural contraction (the native cardiac contractility) sustainably over long periods of time. Furthermore, unlike most interventions that increase cardiac contractility, CCM is not associated with an unfavorable increase in oxygen demand by the heart (measured in terms of Myocardial Oxygen Consumption or MVO2). This may be explained by the beneficial effect CCM has in improving cardiac efficiency. A meta-analysis in 2014 and an overview of device-based treatment options in heart failure in 2013 concluded that CCM treatment is safe, that it is generally beneficial to patients and that CCM treatment increases the exercise tolerance (ET) and quality of life (QoL) of patients. Furthermore, preliminary long-term survival data shows that CCM is associated with lower long-term mortality in heart failure patients when compared with expected rates among similar patients not treated with CCM.