Cardioprotective effects of quinapril after myocardial infarction in hypertensive rats.

Although angiotensin-converting enzyme inhibitors are beneficial for patients with congestive heart failure, the appropriate timing and dosage in acute myocardial infarction are still controversial. We examined the hemodynamic effects of quinapril administered before acute myocardial infarction in spontaneously hypertensive rats (SHR). Quinapril (10 mg/kg per day in drinking water) was started 1 week before infarction and continued for 4 weeks after infarction (total duration 5 weeks). The hemodynamic parameters were evaluated by cardiac catheterization 4 weeks after coronary ligation. Sham-operated SHR served as controls. After infarction, left ventricular end-diastolic and right atrial pressures were increased (P < 0.01) and blood pressure and cardiac index were decreased (P < 0.01); the magnitude of blood pressure reduction was similar in the treated and untreated rats with infarction. Quinapril improved these hemodynamic parameters significantly and decreased left and right ventricular weight. These results suggest that a prior treatment with quinapril in SHR with acute myocardial infarction is hemodynamically beneficial.