Epicardial activation of the intact human heart without conduction defect.

Wyndham, Christopher; Meeran, M K; Smith, Thomas C.; Saxena, Anil; Engelman, Richard M.; Levitsky, Sidney; Rosen, Kenneth M.

doi:10.1161/01.cir.59.1.161

Cited by 111 publications

(47 citation statements)

References 33 publications

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“…1E presents a summary of all imaged epicardial breakthroughs in all seven subjects. Overall, there is good agreement between these breakthrough sites and those observed in an intraoperative study of early activation sites by Wyndham et al (7). Ventricular Electrograms.…”

Section: Resultssupporting

confidence: 78%

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Activation and repolarization of the normal human heart under complete physiological conditions

Ramanathan

Jia

Ghanem

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

229

166

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Knowledge of normal human cardiac excitation stems from isolated heart or intraoperative mapping studies under nonphysiological conditions. Here, we use a noninvasive imaging modality (electrocardiographic imaging) to study normal activation and repolarization in intact unanesthetized healthy adults under complete physiological conditions. Epicardial potentials, electrograms, and isochrones were noninvasively reconstructed. The normal electrophysiological sequence during activation and repolarization was imaged in seven healthy subjects (four males and three females). Electrocardiographic imaging depicted salient features of normal ventricular activation, including timing and location of the earliest right ventricular (RV) epicardial breakthrough in the anterior paraseptal region, subsequent RV and left ventricular (LV) breakthroughs, apex-to-base activation of posterior LV, and late activation of LV base or RV outflow tract. The repolarization sequence was unaffected by the activation sequence, supporting the hypothesis that in normal hearts, local action potential duration (APD) determines local repolarization time. Mean activation recovery interval (ARI), reflecting local APD, was in the typical human APD range (235 ms). Mean LV apex-to-base ARI dispersion was 42 ms. Average LV ARI exceeded RV ARI by 32 ms. Atrial images showed activation spreading from the sinus node to the rest of the atria, ending at the left atrial appendage. This study provides previously undescribed characterization of human cardiac activation and repolarization under normal physiological conditions. A common sequence of activation was identified, with interindividual differences in specific patterns. The repolarization sequence was determined by local repolarization properties rather than by the activation sequence, and significant dispersion of repolarization was observed between RV and LV and from apex to base.noninvasive electrocardiographic imaging ͉ normal cardiac activation and repolarization ͉ normal sinus rhythm U nderstanding normal cardiac excitation provides a necessary baseline for understanding abnormal cardiac electrical activity and rhythm disorders of the heart, a major cause of death and disability. So far, knowledge of normal human cardiac excitation has been obtained mostly through extrapolation from animal studies, including canine (1, 2) and chimpanzee (3). In addition, human data have been obtained from intraoperative epicardial mapping (4-7) and isolated human hearts (8). Extrapolation of animal studies to humans is limited by interspecies differences in anatomy and electrophysiology. Also, the animal and human studies were conducted under nonphysiological conditions (e.g., anesthesia effects and heart exposure during intraoperative mapping; effects of isolation and absence of neural inputs, mechanical loading, and normal perfusion in isolated heart studies). Until now, it has not been possible to study cardiac excitation in intact healthy subjects under normal physiological conditions because of the unavailabili...

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Section: Resultssupporting

confidence: 78%

“…1C Left, 1) that has spread in all directions. Minimum at site 2 [also observed by Durrer et al (8) in isolated hearts] is attributed to an activation front generated by the left-anterior fascicular branch of the left bundle branch (7). Subsequent time frames (not shown) show further development and spread of the breakthrough minima.…”

Section: Resultssupporting

confidence: 60%

Activation and repolarization of the normal human heart under complete physiological conditions

Ramanathan

Jia

Ghanem

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

229

166

View full text Add to dashboard Cite

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“…Except for a small number of studies of epicardial and intramural recordings in isolated postmortem hearts,90 [21][22][23][24][25] prior work in human hearts has been largely limited to the study of epicardial recordings. Our study is the first description of endocardial activation in the intact normal left ventricle.…”

Section: Discussionmentioning

confidence: 99%

Endocardial mapping in humans in sinus rhythm with normal left ventricles: activation patterns and characteristics of electrograms.

Cassidy¹,

Vassallo²,

Marchlinski³

et al. 1984

Circulation

175

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Endocardial catheter mapping was performed in 15 patients in sinus rhythm who had no evidence of structural heart disease and normal left ventricles. Mapping was performed with the use of 10 mm interelectrode distance from various left ventricular endocardial sites. In 10 patients a quantitative analysis of electrographic amplitude, duration, and amplitude/duration ratio was performed. The normal left ventricular bipolar electrograms had an amplitude of greater than 3 mV, a duration of less than 70 msec, and an amplitude/duration ratio of greater than 0.045. Local activation times were also assessed in the 15 patients. This analysis revealed two endocardial breakthrough sites, one on the midinferior septum and a second on the anterior wall near the insertion of the anterior papillary ittuscle. We therefore have defined normal quantitative characteristics of left ventricular bipolar electrograms and the normal left ventricular activation sequence in the intact normal human left ventricle. Circulation 70, No. 1, 37-42, 1984. NORMAL left ventricular endocardial activation and electrographic characteristics in man have not previously been described in vivo. It is imperative to establish normal guidelines if this technique is to be used to evaluate conduction defects, infarction, or arrhythmias. Our study was designed to characterize the electrograms and sequence of ventricular activation obtained during sinus rhythm by catheter endocardial mapping of the normal human left ventricle. MethodsPatient population. Fifteen patients referred to the Hospital of the University of Pennsylvania for electrophysiologic evaluation underwent sinus rhythm endocardial mapping during the course of their examinations. There were eight male and seven female subjects with a mean age of 30 years (range 17 to 64).In no patient was there evidence of structural heart disease. All had normal M mode and two-dimensional echocardiograms. Ten of the 15 patients had normal left ventricular radionuclidegated blood pool scans and in 10 (including five who did not undergo radionuclide-gated blood pool scanning) of the 15 patients results of left heart catheterization and coronary angiographic examination were normal. All patients had normal PR and QRS intervals and normal electrical axes. In two patients intermittent long QT intervals were documented (one drug-related and the other idiopathic). Electrocardiograms of both patients were normal at the time of endocardial mapping. There was no evidence of a preexcitation syndrome in any patient, as determined clinically and by laboratory testing. Electrophysiologic studies were performed to determine the presence or absence of a variety of arrhythmias. Three patients had sustained ventricular tachycardia in the absence of structural heart disease.Electrophysiologic study. Studies were performed in patients in the nonsedated, postabsorptive state after informed written consent had been obtained. Antiarrhythmic drug therapy was discontinued at least five half-lives before endocardial mapping. ...

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“…Until the development of body surface imaging modality, normal atrial and ventricular excitation could be obtained from invasive cardiac catheterisation, intra-operative epicardial mapping 8 or mapping explanted 9 human hearts. With the advent of ECGI, simultaneous 3D recording of whole heart activation is feasible in a normal person under absolute physiological conditions, 10 which have been shown to be in accordance with the observations made and therefore precludes the need for an invasive approach.…”

Section: Normal Cardiac Rhythmmentioning

confidence: 99%

Body Surface Electrocardiographic Mapping for Non-invasive Identification of Arrhythmic Sources

Hocini

Pascale

Roten

et al. 2013

Arrhythmia &Amp; Electrophysiology Review

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The structural and/or functional abnormality of the cardiac electrovascular system is the most common cause of world mortality accounting for 29.0 % of deaths, followed by infectious diseases (16.2 %) and cancers (12.6 %) (WHO 2008 report).1 Abnormalities in the cardiac electrical system (arrhythmias and sudden death) and/or mechanical function (heart failure) constitute one of the major causes of disability and death, which heavily burden the health care systems across the globe. In cardiac electrophysiology and arrhythmias, several decades of research has led to the development of electrocardiographic imaging (ECGI), a novel three-dimensional (3D), 252-lead, body surface ECG-based, non-invasive epicardial imaging modality. This technique images potentials, electrograms and activation sequences (isochrones) on the epicardial surface of the heart. 2 This tool has been investigated in the normal cardiac electrophysiology and various tachyarrhythmic, conduction and anomalous depo-repolarisation disorders. It has been emerging as a tool of potentially higher clinical value than the 12-lead ECG in terms of sensitivity, specificity and accuracy in the diagnostic and therapeutic management of cardiac rhythm disorders.Here we describe the potential of this non-invasive mapping technique developed by Rudy 2 in identifying the sources of electrical disorders of the heart like atrial arrhythmias (premature atrial beat, atrial tachycardia, AbstractThe authors describe a novel three-dimensional, 252-lead electrocardiography (ECG) and computed tomography (CT)-based non-invasive cardiac imaging and mapping modality. This technique images potentials, electrograms and activation sequences (isochrones) on the epicardial surface of the heart. This tool has been investigated in the normal cardiac electrophysiology and various tachyarrhythmic, conduction and anomalous depo-repolarisation disorders. The clinical application of this system includes a wide range of electrical disorders like atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beat, ventricular tachycardia) and ventricular pre-excitation (Wolff-Parkinson-White syndrome). In addition, the system has been used in exploring abnormalities of the His-Purkinje conduction like the bundle branch block and intraventricular conduction disturbance and thereby useful in electrically treating the associated heart failure (cardiac resynchronisation). It has a potential role in furthering our understanding of abnormalities of ventricular action potential (depolarisation [Brugada syndrome and repolarisation], long QT and early repolarisation syndromes) and in evaluating the impact of drugs on His-Purkinje conduction and cardiac action potential.

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Epicardial activation of the intact human heart without conduction defect.

Cited by 111 publications

References 33 publications

Activation and repolarization of the normal human heart under complete physiological conditions

Activation and repolarization of the normal human heart under complete physiological conditions

Endocardial mapping in humans in sinus rhythm with normal left ventricles: activation patterns and characteristics of electrograms.

Body Surface Electrocardiographic Mapping for Non-invasive Identification of Arrhythmic Sources

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