Evaluation of the effect of nifedipine in men after myocardial infarction.

The acute effect of nifedipine (Adalat, Bayer) was evaluated in 54 men with a history of transmural myocardial infarction. Haemodynamic changes (in 20 patients) and/or changes in left ventricular radionuclide ejection fraction (LVREF) (41 patients) were studied. 20 to 30 min after sublingual administration of 1 Adalat capsule (10 mg nifedipine) a decrease in arterial pressure and systemic resistance, and an increase in heart rate and cardiac output were observed already at rest. During exercise (50 W) there moreover occurred a decrease in pulmonary artery pressure and in arterial oxygen tension. LVREF was pathologically reduced already at rest, and in most patients exercise led to its further decrease. LVEF increased after Adalat administration only during exercise. In men with a history of myocardial infarction without clinical manifestations of heart failure, Adalat acted predominantly as a peripheral vasodilator; a negative inotropic effect was not demonstrable. The decrease in arterial oxygen tension, observed during exercise, was not clinically important.