Effects of nifedipine and diltiazem on hemodynamic responses at rest and during exercise in hypertensive patients.

Twelve patients with uncomplicated systemic hypertension were treated with nifedipine (30 mg/day) and diltiazem (180 mg/day) for 1 month each, and performed two stage (50 watt and 100 watt) of bicycle ergometer exercise before and after each period of administration. Both drugs produced significant reduction in systolic and diastolic blood pressure at rest and during exercise, while the mean values of systolic blood pressure tended to be less with nifedipine than with diltiazem. Nifedipine caused a nonsignificant increase in heart rate at rest and during exercise, but diltiazem significantly decreased it at rest and during exercise. Cardiac output was significantly increased at rest and during mild exercise (50 watt), but not during more strenuous exercise (100 watt) with both drugs. Thus, different actions in arterial vasodilation and chronotropism between nifedipine and diltiazem in usual clinical doses were noted. However, nifedipine and diltiazem may be effective in hypertensive patients, probably with left ventricular dysfunction, because both drugs reduced systemic blood pressure even during exercise with simultaneous increase in cardiac output at rest and during mild exercise.