Author + information
- Received July 16, 1984
- Revision received June 4, 1985
- Accepted August 1, 1985
- Published online January 1, 1986.
- ↵aAddress for reprints: Judith S. Hochman, MD, Director, Cardiac Care Unit, St. Luke's Hospital, 114th Street, New York, New York 10025.
Infarct expansion, the time-related thinning and dilation of an acute transmural infarct, leads to aneurysm formation and cardiac rupture in humans. In this study, the effect of exercise on acute infarct expansion early after myocardial infarction was examined in 129 rats. Ninety rats were exercised on a treadmill for 1.5 hours daily for I week beginning on the day of coronary artery ligation; the remaining 39 rats remained in their cages. There was no effect on the prevalence or extent of expansion; specifically, infarct wall thickness, left ventricular diameter and expansion grade (0 to 4 +) were similar in the exercise and control rats. There was no difference in infarct size or the number of animals with aneurysmal shape changes in the exercise and control groups. There was no significant difference between the two groups in the histologic finding of intramural hemorrhage, a feature that has been associated with cardiac rupture, and no complete rupture was seen. However, there was a nonsignificant trend toward higher mortality in the exercised group.
Thus, the findings of this study suggest that moderate exercise early after myocardial infarction produces no significant detrimental effect on infarct size or left ventricular topography in the rat model.
↵1 Dr. Hochman is a recipient of the Pearl M. Stetler Research Fellowship, Chicago, Illinois.
This study was supported by Ischemic Heart Disease Specialized Center for Research Grant P50-HL-17655-05 and Training Grant 5-T32-HL-07227 from the National Institutes of Health, Bethesda, Maryland, an American Heart Association grant-in-aid award, Maryland Affiliate and The Peter Belfer Laboratory for Myocardial Research, Baltimore, Maryland.
- Received July 16, 1984.
- Revision received June 4, 1985.
- Accepted August 1, 1985.
- American College of Cardiology Foundation