Ciampricotti et al. December 1990 American Heart Journal premature mortality by high physical activity; a 20-year 75. Angelini P, Trivellato M, Donis J, Leachman RD. Myocardial follow-up of middle-aged Finnish men. Lancet 1987;2:1473. bridges: a review. Prog Cardiovasc Dis 1983;26:75. 73. Morales A, Romanelli R, Boucek R. The mural left anterior 76. Maron BJ, Roberts WC, McAllister HA, Rosing DR, Epstein descending coronary artery, strenuous exercise and sudden death. Circulation 1980:62:230. 74. Noakes TD, Rose AG, Gpie LH. Hypertrophic cardiomyopa- thy associated with sudden death during marathon racing. Br Heart J 1979;41:624. SE. Sudden death in young athletes. Circulation 1980;62:218. 77. Mattfeldt T. Schwarz F. Schuler G. Hoffmann M. Kiibler W. Necropsy evaluation in’ seven patients with evolving acute myocardial infarction treated with thrombolytic therapy. Am J Cardiol 1984;54:530. Effects of exercise on myocardial catecholamine content and ischemic injury in dogs with gradual coronary occlusion The effects of exercise on catecholamine content and the extent of myocardial damage in dogs with Ameroid constrictor occlusion of the left circumflex coronary artery were determined. Tissue samples from both the anterior and posterior walls of the left ventricle were obtained for determination of catecholamine content, and the rest of the ventricles were processed for histologic examination. When subjected to treadmill exercise for 40 days after surgery, obstructed animals performed significantly less exercise than sham-operated animals and showed significantly higher percentages of ischemia and necrosis in the left ventricle than sedentary, obstructed, sham-operated, or control dogs. Levels of norepinephrlne and epinephrlne in the posterior wall of the left ventricle were significantly lower than in the other groups. Our data show that exercise in this well-known model of chronic coronary artery stenosis produced deleterious effects on the myocardium and suggest a marked heterogeneity of catecholamine stores in the myocardium that may have important functional and electrophysiologic consequences. (AM HEART J 1990; 120~1278.) Herminio Rojo, MD, Ines Armando, PhD, Maria Morales, MD, Gloria Levin, PhD, Miguel Roseman, and Marta Barontini, MD. Buenos Aires, Argentina In recent years exercise has been advocated for pre- ventive, diagnostic, and/or rehabilitative purposes to minimize the problems associated with coronary heart disease. Physiologically exercise training has been shown to alter the autonomic nervous system and autonomic control of the heart1 When coronary blood flow is restricted, augmented sympathetic stimulation by exercise can produce or enhance my- ocardial ischemia.2 It has been shown that acute is- chemic injury is associated with the redistribution From the Department of Research and Teaching, Favaloro Foundation, and the Centro de Investigaciones Endocrinokgicas (CEDIE-CONICET), Hos- pital de Nixios “R. Gutikrrez.” Supported by grants from the Favaloro Foundation and the Consejo Nacio- nal de Investigaciones Cientificas y T&micas, Argentina (PID 304830088). Received for publication Oct. 27, 1989; accepted June 18, 1990. Reprint requests: Herminio Rojo, MD, Fundaci6n Favaloro, Solis 453,1078 Buenos Aires, Argentina. 4/l/24126 1278 and abnormal localization of catecholamines in is- chemic myocardium.3 Results of previous studies have shown that infarcted tissue shows a marked de- crease in norepinephrine levels.4 However, little is known about how exercise in the presence of chronic coronary stenosis affects myocardial catecholamine content. To date there has been no systematic examination on the effects of exercise on both catecholamine stores in the heart muscle and the extention of ischemic and necrotic areas. We report here the effects of exercise on these parameters in conscious dogs with chronic occlusion of the left circumflex coronary artery. METHODS Twenty-six adult mongrel dogs, aged 4 + 1 years as judged by inspection of their teeth, weighing 16 to 22 kg, were included in this study. All animals were carefully se-