Effect of nifedipine on exercise tolerance in patients with angina pectoris.

To test if nifedipine, 10 mg sublingually, could increase exercise tolerance, ten patients with angina pectoris each performed two types of bicycle exercise test, one with a stepwise increase in load and the other with a continuously increasing load. The drug was given in a double-blind cross-over trial. Nifedipine raised the heart rate and diminished the systemic blood pressure at rest, on standing and during exercise at comparable loads. Work time was prolonged and higher work loads were achieved. The total work performed rose by 50 per cent in one of the tests and by 23 per cent in the other, about 50 minutes after taking the drug. The mechanism of the greater work capacity in angina pectoris after nifedipine was assumed to be diminished heart work due to a fall in systemic vascular resistance.