What Have We Learned About Cardiac Arrhythmias?

Zipes, Douglas P.; Wellens, Hein J.J.

doi:10.1161/01.cir.102.suppl_4.iv-52

Cited by 23 publications

(13 citation statements)

References 53 publications

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“…The proclivity to these malignant arrhythmias may be secondary to both structural myocardial changes and heterogeneity in regional distribution and activity of sympathetic nerves (22,31). Prior studies in animal models of myocardial infarction have shown that coronary occlusion causes nerve cell injury and death.…”

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confidence: 99%

Sympathetic stimulation increases dispersion of repolarization in humans with myocardial infarction

Vaseghi

Lux

Mahajan

et al. 2012

American Journal of Physiology-Heart and Circulatory Physiology

120

113

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The sympathetic nervous system is thought to play a key role in genesis and maintenance of ventricular arrhythmias. The myocardial effect of sympathetic stimulation on myocardial repolarization in humans is poorly understood. The purpose of this study was to evaluate the effects of direct and reflex sympathetic stimulation on ventricular repolarization in patients with postinfarct cardiomyopathy (ICM). The effects of direct sympathetic stimulation were assessed using isoproterenol, while those of reflex sympathetic stimulation were assessed with nitroprusside infusion in ICM patients (n = 5). Five patients without cardiomyopathy were also studied. Local repolarization was measured from intracardiac electrograms that were used to calculate the activation recovery interval (ARI), a surrogate of action potential duration. Isoproterenol significantly increased heterogeneity in repolarization in patients with ICM; the decrease in ARI from baseline was 72.9 ± 9.1 ms in more viable regions, 64.5 ± 8.9 ms in the scar, and 54.9 ± 9.1 ms in border zones (P = 0.0002 and 0.014 comparing normal and scar to border zones, respectively). In response to nitroprusside, the ARI at the border zones decreased significantly more than either scar or surrounding viable myocardium, which showed an increase in ARI (P = 0.014 and 0.08 comparing normal tissue and scar to border zones, respectively). Furthermore, isoproterenol increased ARI dispersion by 70%, while nitroprusside increased ARI dispersion by 230% when ICM patients were compared to those with structurally normal hearts (P = 0.0015 and P < 0.001, respectively). In humans, both direct and reflex sympathetic stimulations increase regional differences in repolarization. The normal tissue surrounding the scar appears denervated. Dispersion of ARI in response to sympathetic stimulation is significantly increased in patients with ICM.

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confidence: 99%

Sympathetic stimulation increases dispersion of repolarization in humans with myocardial infarction

Vaseghi

Lux

Mahajan

et al. 2012

American Journal of Physiology-Heart and Circulatory Physiology

120

113

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“…1 Five pivotal prospective, randomized, clinical trials have helped define its use. In 3 secondary prevention trials, Antiarrhythmics Versus Implantable Defibrillators (AVID), Canadian Implantable Defibrillator Study (CIDS), and Cardiac Arrest Survival Hamburg (CASH), 2 and 2 primary prevention trials, Multicenter Automatic Defibrillator Implantation Trial (MADIT) 3 and Multicenter Unsustained Tachycardia Trial (MUSTT), 4 the ICD was superior to antiarrhythmic drugs (mostly or exclusively amiodarone) in reducing mortality in patients with life-threatening ventricular tachyarrhythmias.…”

Section: See P 1416mentioning

confidence: 99%

Implantable Cardioverter-Defibrillator: A Volkswagen or a Rolls Royce

Zipes

2001

Circulation

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“…7 Ambulatory ECG has led to many new insights, including an understanding of the mechanisms of sudden cardiac death, causes of syncope and the concept of painless ischemia. 8 Gatzouliset al found that abnormal findings on 24-hour Holter monitoring are well correlated with potential bradycardia and/or tachyarrhythmia causes of syncope, in electrophysiological study of patients with undiagnosed syncope. 9 This study was conducted to evaluate the incidence of arrhythmia on 24-hour electrocardiographic Holter monitoring.…”

Section: Introductionmentioning

confidence: 99%