title: Morphometry of right ventricular hypertrophy induced by myocardial infarction in the rat.
abstract: The growth response of the right ventricle was studied in rats following ligation of the left coronary artery, which produced infarcts comprising approximately 40% of the left ventricle. A month after surgery the weight of the right ventricle was increased 30%, and this hypertrophic change was characterized by a 17% wall thickening, consistent with the 13% greater diameter of myocytes. Myocardial hypertrophy was accompanied by an inadequate growth of the microvasculature that supports tissue oxygenation. This was seen by relative decreases in capillary luminal volume density (-27%) and capillary luminal surface density (-21%) and by an increase in the average maximum distance from the capillary wall to the mitochondria of myocytes (19%). In contrast, measurements of the mean myocyte volume per nucleus showed a proportional enlargement of these cells (32%), from 16,300 cu mu in control animals to 21,500 cu mu in experimental rats. Quantitative analysis of the right coronary artery revealed a 33% increase in its luminal area, commensurate with the magnitude of ventricular hypertrophy.
mesh_terms: D000818:Animals; D002196:Capillaries / Q000473:pathology; D006332:Cardiomegaly / Q000209:etiology / Q000473:pathology*; D003331:Coronary Vessels / Q000473:pathology; D008297:Male; D009203:Myocardial Infarction / Q000150:complications*; D009206:Myocardium / Q000473:pathology*; D051381:Rats