CARDIOPULMONARY RESPONSE DURING EXERCISE OF A BETA(1)-SELECTIVE BETA-BLOCKER (ATENOLOL) AND A CALCIUM-CHANNEL BLOCKER (DILTIAZEM) IN UNTRAINED SUBJECTS WITH HYPERTENSION

The effects of beta-blockers and calcium-channel blockers on cardiopul monary response during exercise are not well characterized. Sixteen se dentary patients with essential hypertension underwent a randomized, d ouble-blind, cross-over study comparing atenolol and diltiazem sustain ed-release 300 mg, each administered during 6 weeks, after a 15-day ru n-in placebo period. Neither atenolol nor diltiazem significantly affe cted maximal exercise duration, maximal oxygen uptake, ventilatory thr eshold, Or any of the ventilatory parameters during exercise. With ate nolol, the maximal oxygen pulse was significantly increased and compen sated for the decrease in heart rate during exercise. Atenolol and dil tiazem do not limit maximal exercise tolerance in untrained hypertensi ve subjects, but the circulatory profile is more preserved with diltia zem.