title: Regional myocardial hypertrophy induced by repeated brief coronary occlusion in conscious dogs.
abstract: The purpose of the present study was to evaluate whether repeated brief coronary occlusion induces myocardial hypertrophy in the region subjected to reversible ischemic insult. In five conscious dogs, a subendocardial segment length in the area perfused by the left circumflex coronary artery (LCCA) was measured along with left ventricular pressure. After complete recovery from surgery, 167 (mean) 2-minute LCCA occlusions were repeated for 22 days. Before and after repeated coronary occlusion, the resting heart rate, left ventricular systolic and end-diastolic pressures, and dP/dt were unchanged. The resting end-diastolic segment length in the LCCA area was increased by 6.6% (p less than 0.05). On histologic examination, there was a disproportionate increase in myocardial cell size in the LCCA area compared with the area perfused by the left anterior descending coronary artery (LAD) (18.2 mu vs 15.4 mu, p less than 0.05). In an additional similarly instrumented five dogs, myocardial cell size in the LCCA and LAD areas was comparable (14.2 mu vs 14.0 mu, p = NS). We conclude that the repeated brief ischemic episodes induce regional myocardial hypertrophy confined to the ischemic area.
authors: Second Department of Internal Medicine, Toyama Medical and Pharmaceutical University, Japan.
authors: K
authors: K
authors: Yamanishi
authors: M
authors: M
authors: Fujita
authors: E
authors: E
authors: Araie
authors: A
authors: A
authors: Ohno
authors: S
authors: S
authors: Sasayama
authors: E
authors: E
authors: Okada
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001794:Blood Pressure; D009202:Cardiomyopathies / Q000209:etiology / Q000473:pathology*; D003327:Coronary Disease / Q000150:complications; D004195:Disease Models, Animal; D004285:Dogs; D006984:Hypertrophy; D007511:Ischemia; D009206:Myocardium / Q000473:pathology; D012008:Recurrence; D016277:Ventricular Function, Left