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This Article Full Text Full Text (PDF) All Versions of this Article: 289/6/H2688    most recent 00653.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Fallavollita, J. A. Articles by Canty, J. M. Search for Related Content PubMed PubMed Citation Articles by Fallavollita, J. A. Articles by Canty, J. M., Jr.

Mechanism of sudden cardiac death in pigs with viable chronically dysfunctional myocardium and ischemic cardiomyopathy

Department of Veterans Affairs Western New York Health Care System, Center for Research in Cardiovascular Medicine, and Departments of Medicine and Physiology and Biophysics, University at Buffalo, Buffalo, New York

Submitted 17 June 2005 ; accepted in final form 29 July 2005

Pigs with viable chronically dysfunctional myocardium and ischemic cardiomyopathy are at high risk of sudden cardiac death (SCD). We sought to identify the arrhythmic mechanism of SCD, the relation to changes in left ventricular (LV) function, and inducibility of malignant arrhythmias before SCD. Juvenile pigs (n = 72) were instrumented with chronic stenoses on proximal left anterior descending and circumflex arteries. Survival was only 29% 3 mo after instrumentation, and all deaths were sudden and without prodromal symptoms of heart failure. Triphenyltetrazolium chloride staining demonstrated necrosis in only nine animals averaging 2.3 ± 0.9% of the LV, with no difference between SCD animals and survivors. Implantable loop recorders (n = 13) documented both ventricular fibrillation (n = 6) and bradyasystole (n = 2) as the arrhythmic mechanism of death. Although regional and global function were depressed [anteroseptal wall thickening 1.8 ± 0.2 vs. 4.2 ± 0.2 mm in Sham animals (P < 0.001); fractional shortening 21 ± 2 vs. 31 ± 1% in Sham animals (P < 0.01)], there were no differences between SCD animals and survivors. LV mass increased in animals with ischemic cardiomyopathy and was greater in animals with SCD (4.0 ± 0.2 vs. 3.1 ± 0.1 g/kg in survivors; P < 0.001). Serial programmed ventricular stimulation failed to induce any sustained arrhythmias. We conclude that pigs with viable dysfunctional myocardium and globally reduced LV function have a high rate of SCD with a spectrum of arrhythmias similar to patients with ischemic cardiomyopathy. The risk is independent of necrosis but appears to increase with LV hypertrophy. Like patients with ischemic cardiomyopathy, programmed stimulation is insensitive to predict SCD when viable dysfunctional myocardium is the pathological substrate.

hibernating myocardium; arrhythmias

This article has been cited by other articles:

				M. D. Banas, S. Baldwa, G. Suzuki, J. M. Canty Jr., and J. A. Fallavollita Determinants of contractile reserve in viable, chronically dysfunctional myocardium Am J Physiol Heart Circ Physiol, June 1, 2007; 292(6): H2791 - H2797. [Abstract] [Full Text] [PDF]