Effects of Adalat (nifedipine) on left ventricular hemodynamics in angina pectoris: comparative study with...

The hemodynamic effects of nifedipine and propranolol administered intravenously were studied in 17 patients with angina pectoris. Nine patients received nifedipine and eight received propranolol. The hemodynamic parameters were compared at rest and during supine bicycle exercise at work loads known to produce angina. Exercise-induced angina improved in four out of nine patients following nifedipine and in one out of eight patients following propranolol. Nifedipine significantly reduced the increment of left ventricular end-diastolic pressure and Vmax during exercise. Intravenous propranolol significantly suppressed the increment of heart rate, max dp/dt, tension time index, and Vmax during exercise. Although the exact mode of action of nifedipine remains uncertain, it is suggested that it decreases myocardial oxygen requirements primarily through a reduction of left ventricular volume, whereas propranolol suppresses the positive chronotropic and inotropic responses of the heart muscle to exercise.