MODIFICATION OF EXERCISE PERFORMANCE BY SHARP REDUCTION OF BLOOD-PRESSURE - A STUDY IN PATIENTS WITH UNCOMPLICATED HYPERTENSION

We evaluated exercise performance in 14 patients with uncomplicated es sential hypertension 1 h after the administration of a single dose of placebo, nifedipine (20 mg), captopril (50 mg), and propranolol (80 mg ). Drugs were administer.ed at the same time of day following a random ized, double-blind protocol. Mean resting blood pressure (+/-SE) was 1 35+/-3 mm Hg with placebo administration, 118+/-4 with captopril, 110/-4 with nifedipine, and 115+/-5 with propranolol and increased with e xercise to 163+/-4, 146+/-3, 136+/-4, 136+/-4, respectively. Oxygen co nsumption at peak exercise and at ventilatory anaerobic threshold (VAT ) was 25.2+/-1.1 and 18.1+/-1.0 ml/min/kg with placebo. Only propranol ol (- 2.3 ml/min/kg) decreased peak exercise oxygen consumption. Oxyge n consumption at VAT was reduced by nifedipine and propranolol but una ffected by captopril. The effects on exercise capacity of blood pressu re reduction in hypertensive patients are dependent on the drug utiliz ed and are not related to the amount of blood pressure reduction. The lowered oxygen consumption at VAT observed with nifedipine and propran olol, and not with captopril, might be due to an excessive downward sh ift of the muscle perfusion pressure-oxygen consumption relationship w hich might take place during exercise.