Effect of nipradilol on cardiovascular hemodynamics during exercise in angina pectoris with old myocardial infarction

Nipradilol (3,4-dihydro-(2-hydroxy-3-isopropylamino)-propoxy-3-nitroxy-2H-1- benzopyran, K-351, CAS 81486-22-8) is a new type of beta-blocker with vasodilating action. The effect of nipradilol on hemodynamics at rest and during exercise with a multi-stage bicycle ergometer in supine position was studied in 8 male patients suffering from angina pectoris with old myocardial infarction. Nipradilol was orally given at the daily dose of 12 mg (b.i.d.) for one week, and various hemodynamic parameters were measured at rest and during exercise before and after the treatment with nipradilol. At rest, the blood pressure was almost unchanged, heart rate was significantly reduced, cardiac output tended to decrease, and the pulmonary blood pressure and left ventricular ejection fraction (EF) were almost unchanged. At peak exercise, the blood pressure tended to decline, heart rate was significantly reduced, cardiac output tended to decrease and the pulmonary blood pressure and EF increased significantly. Consequently, the antianginal effect of nipradilol is considered to be attributable to the reduction in myocardial oxygen consumption caused by a decrease in double product. It is thus suggested that nipradilol exerts its antianginal effect without adversely affecting the cardiac performance.