Effects of angiotensin II type 1 receptor antagonist, YM358, on cardiac hypertrophy and dysfunction after myocardial infarction in rats.

This study was undertaken to investigate the effects of an angiotensin II type 1 receptor antagonist, YM358 (2,7-diethyl-5-[[2'(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-5H-pyrazolo [1,5-b] [1,2,4]triazole potassium salt monohydrate), on cardiac hypertrophy and dysfunction in rats with heart failure after myocardial infarction (MI). One day after the coronary ligation, rats were randomized, and administered YM358 or vehicle for 2, 4 or 8 weeks. In MI rats, mean blood pressure, left ventricular (LV) systolic pressure, and the first derivative of LV pressure significantly decreased, and LV end-diastolic pressure (LVEDP) markedly increased after 2 to 8 week treatment of YM358.