Impaired cardiac autonomic control relates to disease severity in pulmonary hypertension
... The data from CIARKA et al. [9] suggest that sympathetic activity is directly related to the severity of the underlying haemodynamic failure with increased right atrial pressures and low cardiac output in PAH. However, the changes in cardiac autonomic nervous activity observed in our study parallel ...
... The data from CIARKA et al. [9] suggest that sympathetic activity is directly related to the severity of the underlying haemodynamic failure with increased right atrial pressures and low cardiac output in PAH. However, the changes in cardiac autonomic nervous activity observed in our study parallel ...
Deciphering the Sinus Tachycardias
... positively coupled to adenyl cyclase. Activation of these receptors leads to an increase in cyclic adenosine monophosphate (cAMP) which directly triggers the opening of the inward sodium channels responsible for the “funny” current and indirectly stimulates opening of “L-type” calcium channels. The ...
... positively coupled to adenyl cyclase. Activation of these receptors leads to an increase in cyclic adenosine monophosphate (cAMP) which directly triggers the opening of the inward sodium channels responsible for the “funny” current and indirectly stimulates opening of “L-type” calcium channels. The ...
Print - Circulation
... When Harvey proved the circulation of the blood in so many different and convincing ways, he found himself confronted by this question, too. But he also could only approach the mystery with conjectures. ". . Either there is connection between the vessels," he wrote, "or else there must be pores allo ...
... When Harvey proved the circulation of the blood in so many different and convincing ways, he found himself confronted by this question, too. But he also could only approach the mystery with conjectures. ". . Either there is connection between the vessels," he wrote, "or else there must be pores allo ...
Understanding Arrythmias
... Types of Arrhythmias • Atrial flutter (AFL) is similar to atrial fibrillation in that it is characterized by a rapid heartbeat, sometimes up to 4 times faster than normal that originates in the atria. It differs from atrial fibrillation (AF) in that the heartbeat is regular, not irregular. Atrial fl ...
... Types of Arrhythmias • Atrial flutter (AFL) is similar to atrial fibrillation in that it is characterized by a rapid heartbeat, sometimes up to 4 times faster than normal that originates in the atria. It differs from atrial fibrillation (AF) in that the heartbeat is regular, not irregular. Atrial fl ...
Effect of Systemic Hypoxia and Reoxygenation on Electrical Stability
... The aim of the study was to determine the dependence of changes in the electrical stability of the heart on the light-dark cycle (LD cycle) in disorders of pulmonary ventilation. The ventricular arrhythmia threshold (VAT) was measured in female Wistar rats (adaptation to the light regime 12:12 h, ke ...
... The aim of the study was to determine the dependence of changes in the electrical stability of the heart on the light-dark cycle (LD cycle) in disorders of pulmonary ventilation. The ventricular arrhythmia threshold (VAT) was measured in female Wistar rats (adaptation to the light regime 12:12 h, ke ...
Congenital heart disease is no longer a paediatric specialty
... cardiac, related to CHD with only a few exceptions of milder lesions such as early corrected atrial septal defect and patent ductus arteriosus. The leading causes of death are heart failure, sudden death (mainly due to arrhythmia), and operative death at the time of surgical re-intervention. It is p ...
... cardiac, related to CHD with only a few exceptions of milder lesions such as early corrected atrial septal defect and patent ductus arteriosus. The leading causes of death are heart failure, sudden death (mainly due to arrhythmia), and operative death at the time of surgical re-intervention. It is p ...
Longitudinal Hemodynamic Measurements in Swine System
... Radio-telemetry is an alternative method that addresses some of these shortcomings. It provides continuous recordings without stress from any exogenous factors. This technology has been developed and tested in both small and large animals [2,16,24,25]. Most systems, however, only include channels fo ...
... Radio-telemetry is an alternative method that addresses some of these shortcomings. It provides continuous recordings without stress from any exogenous factors. This technology has been developed and tested in both small and large animals [2,16,24,25]. Most systems, however, only include channels fo ...
NIH Public Access - Scientific Computing and Imaging Institute
... Relative Pseudo-DFTs are defined as the primary outcome measure for this study, and are a measure of the interaction the electrical field generated by an ICD shock with the ventricular myocardium. The pseudo-DFT is calculated for each electrode configuration as the shock energy E = ½ CV2, where C is ...
... Relative Pseudo-DFTs are defined as the primary outcome measure for this study, and are a measure of the interaction the electrical field generated by an ICD shock with the ventricular myocardium. The pseudo-DFT is calculated for each electrode configuration as the shock energy E = ½ CV2, where C is ...
The Effect of Cardiac Resynchronization on Morbidity and Mortality
... or investigator decided not to proceed. A cardiacAll prespecified analyses were conducted according resynchronization device was implanted and activatto the intention-to-treat principle. P values other ed in 390 patients (95 percent), in 349 on the first than for the primary end point are nominal. T ...
... or investigator decided not to proceed. A cardiacAll prespecified analyses were conducted according resynchronization device was implanted and activatto the intention-to-treat principle. P values other ed in 390 patients (95 percent), in 349 on the first than for the primary end point are nominal. T ...
Breathing and Cardiac Emergencies Outline
... o Rescue breathing- _________ breathe of air every __________ seconds as long as the pulse is present o ...
... o Rescue breathing- _________ breathe of air every __________ seconds as long as the pulse is present o ...
MAIN TRIBUTARIES OF THE CORONARY SINUS IN THE
... coronary sinus. Researches of other authors confirm that the main heart vein is found (Ratajczyk-Pakalska 1970, Warwick at al. 1989) in 100% of humans and other primates and invariably directs towards the coronary sinus. Only Poirier and Charpy, as noted in Ratajczyk-Pakalska (1974), found a variety ...
... coronary sinus. Researches of other authors confirm that the main heart vein is found (Ratajczyk-Pakalska 1970, Warwick at al. 1989) in 100% of humans and other primates and invariably directs towards the coronary sinus. Only Poirier and Charpy, as noted in Ratajczyk-Pakalska (1974), found a variety ...
PBMB - MEF Review_submitted_UNMARKED
... feed-back loops by which the mechanical state of the heart acutely alters ion channel function and/or electrical conduction (mechano-electric coupling, MEC; reviewed in (Kohl et al., 1999; Quinn et al., 2014b)), or intra-cellular Ca2+ handling and Ca2+-myofilament interactions (mechano-mechanical co ...
... feed-back loops by which the mechanical state of the heart acutely alters ion channel function and/or electrical conduction (mechano-electric coupling, MEC; reviewed in (Kohl et al., 1999; Quinn et al., 2014b)), or intra-cellular Ca2+ handling and Ca2+-myofilament interactions (mechano-mechanical co ...
Ivabradine in Stable Coronary Artery Disease without Clinical Heart
... treatment on the primary end point and other time-to-event end points, with adjustment for the presence or absence of activity-limiting angina pectoris (CCS class ≥II) at baseline. Results are presented as hazard ratios and 95% confidence intervals with corresponding P values. Prespecified subgroup ...
... treatment on the primary end point and other time-to-event end points, with adjustment for the presence or absence of activity-limiting angina pectoris (CCS class ≥II) at baseline. Results are presented as hazard ratios and 95% confidence intervals with corresponding P values. Prespecified subgroup ...
Exercise Tolerance Testing - Cardiac and Stroke Networks in
... •Angina is usually provoked by exertion, nearly always of walking •The amount of exercise required to provoke Angina varies in any individual •Emotion, tachycardia may provoke Angina Duration of the attack Most attacks last 1-3 minutes. The duration is seldom less than 30 seconds or more than 15 min ...
... •Angina is usually provoked by exertion, nearly always of walking •The amount of exercise required to provoke Angina varies in any individual •Emotion, tachycardia may provoke Angina Duration of the attack Most attacks last 1-3 minutes. The duration is seldom less than 30 seconds or more than 15 min ...
In Vivo Measurements of Atrial Repolarization Alternans
... alternans appeared rate-dependent and its amplitude increased as a function of pacing rate. Repolarization alternans was intermittent but no periodicity was detected. An increase of repolarization alternans preceding episodes of non-sustained atrial fibrillation suggests that repolarization alternan ...
... alternans appeared rate-dependent and its amplitude increased as a function of pacing rate. Repolarization alternans was intermittent but no periodicity was detected. An increase of repolarization alternans preceding episodes of non-sustained atrial fibrillation suggests that repolarization alternan ...
preexcitation
... usually of no clinical significance • However, preexcitation (specifically WPW) can predispose the patient to various tachydysrhythmias • The most common tachydysrhythmia is atrioventricular reentrant tachycardia (AVRT), followed by atrial fibrillation and atrial flutter – Atrial fibrillation and at ...
... usually of no clinical significance • However, preexcitation (specifically WPW) can predispose the patient to various tachydysrhythmias • The most common tachydysrhythmia is atrioventricular reentrant tachycardia (AVRT), followed by atrial fibrillation and atrial flutter – Atrial fibrillation and at ...
Unit 2 06
... arterial pressure increased markedly because of sympathetic withdrawal. C. cerebral vascular hyperemia exceeded the requirement for passive local vasoconstriction. D. stroke volume decreased more than heart rate increased causing a pronounced decrease in cardiac output. E. none of the above is corre ...
... arterial pressure increased markedly because of sympathetic withdrawal. C. cerebral vascular hyperemia exceeded the requirement for passive local vasoconstriction. D. stroke volume decreased more than heart rate increased causing a pronounced decrease in cardiac output. E. none of the above is corre ...
Hyperglycemia Increases New-Onset Atrial Fibrillation in Patients
... accompanied by an increased morbidity and mortality. The aim of this study was to investigate the predictors and outcome of new-onset AF occurring after acute ST-elevation myocardial infarction (STEMI). Methods: A total of 307 patients with acute STEMI from May 2007 to June 2009 were included in our ...
... accompanied by an increased morbidity and mortality. The aim of this study was to investigate the predictors and outcome of new-onset AF occurring after acute ST-elevation myocardial infarction (STEMI). Methods: A total of 307 patients with acute STEMI from May 2007 to June 2009 were included in our ...
Pacemakers - Houston Electrophysiology Associates
... unit is slightly larger than a man’s wristwatch and contains a battery and computer circuits (Figure 1). The computer circuits perform the functions of monitoring the patient’s underlying heart rhythm and delivering an electrical signal to cause the heart to beat at the desired rate. Many pacemakers ...
... unit is slightly larger than a man’s wristwatch and contains a battery and computer circuits (Figure 1). The computer circuits perform the functions of monitoring the patient’s underlying heart rhythm and delivering an electrical signal to cause the heart to beat at the desired rate. Many pacemakers ...
Control of Cardiac Output 2 - Dr. Ford
... show these graphically as well as how variations in each factor affect this graphical representation. Specifically: a. Describe the role that the ratio of arterial to venous compliance and total peripheral resistance plays in the graphical description of the venous return. b. Discuss the notions of ...
... show these graphically as well as how variations in each factor affect this graphical representation. Specifically: a. Describe the role that the ratio of arterial to venous compliance and total peripheral resistance plays in the graphical description of the venous return. b. Discuss the notions of ...
Autonomic control of the heart in Boa constrictor
... 41.3±1.9 % during activity, respectively. Double Reptiles, particularly snakes, exhibit large and autonomic block virtually abolished tachycardia quantitatively similar increments in metabolic rate during associated with enforced activity (heart rate increased muscular exercise and following a meal, ...
... 41.3±1.9 % during activity, respectively. Double Reptiles, particularly snakes, exhibit large and autonomic block virtually abolished tachycardia quantitatively similar increments in metabolic rate during associated with enforced activity (heart rate increased muscular exercise and following a meal, ...
Chapter 11 ppt - Fillmore Central Schools
... Atrioventricular bundle (Bundle of His) Bundle branches (right and left) Purkinje fibers Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings ...
... Atrioventricular bundle (Bundle of His) Bundle branches (right and left) Purkinje fibers Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings ...
Nondestructive optical determination of fiber organization in intact
... across the left ventricular wall. Panel A shows optical sections at the center of a guinea pig LV, which run from epi- (z 5 0 lm) to endocardium (z 5 1,600 lm) in steps of 200 lm. Fiber orientation exhibits a gradual counterclockwise rotation with depth. To quantitatively analyze this rotation, we d ...
... across the left ventricular wall. Panel A shows optical sections at the center of a guinea pig LV, which run from epi- (z 5 0 lm) to endocardium (z 5 1,600 lm) in steps of 200 lm. Fiber orientation exhibits a gradual counterclockwise rotation with depth. To quantitatively analyze this rotation, we d ...
Computed Tomography Features of Left Ventricular
... this entity. Some authors argue that CTA is of limited role and suggest that due to less availability and higher cost, it should not be considered as the first line imaging method (12). However, we do not agree with this comment. As in our case, CTA can well depict many of the diagnostic features of ...
... this entity. Some authors argue that CTA is of limited role and suggest that due to less availability and higher cost, it should not be considered as the first line imaging method (12). However, we do not agree with this comment. As in our case, CTA can well depict many of the diagnostic features of ...
The Heart
... valve flaps from everting into atria AV valves closed (a) Figure 11.5a, step 6 Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings ...
... valve flaps from everting into atria AV valves closed (a) Figure 11.5a, step 6 Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings ...
Electrocardiography
Electrocardiography (ECG or EKG*) is the process of recording the electrical activity of the heart over a period of time using electrodes placed on a patient's body. These electrodes detect the tiny electrical changes on the skin that arise from the heart muscle depolarizing during each heartbeat.In a conventional 12 lead ECG, ten electrodes are placed on the patient's limbs and on the surface of the chest. The overall magnitude of the heart's electrical potential is then measured from twelve different angles (""leads"") and is recorded over a period of time (usually 10 seconds). In this way, the overall magnitude and direction of the heart's electrical depolarization is captured at each moment throughout the cardiac cycle. The graph of voltage versus time produced by this noninvasive medical procedure is referred to as an electrocardiogram (abbreviated ECG or EKG).During each heartbeat, a healthy heart will have an orderly progression of depolarization that starts with pacemaker cells in the sinoatrial node, spreads out through the atrium, passes through the atrioventricular node down into the bundle of His and into the Purkinje fibers spreading down and to the left throughout the ventricles. This orderly pattern of depolarization gives rise to the characteristic ECG tracing. To the trained clinician, an ECG conveys a large amount of information about the structure of the heart and the function of its electrical conduction system. Among other things, an ECG can be used to measure the rate and rhythm of heartbeats, the size and position of the heart chambers, the presence of any damage to the heart's muscle cells or conduction system, the effects of cardiac drugs, and the function of implanted pacemakers.