Long-term management of exercise-induced myocardial ischemia. Diltiazem versus propranolol, a double-blind, crossover study.

The authors performed a long-term, double-blind, crossover study on the effect of two drugs (propranolol, 40 mg t.i.d. or diltiazem, 60 mg t.i.d., each administered for 2 months) on their exercise tolerance in 13 patients with stable angina (mean age 52 +/- 7 years, 9 males and 4 females), after exertion and documented significant (greater than or equal to 70%) obstructive coronary lesions at angiography. Only propranolol, by decreasing heart rate and rate-pressure product, improved maximal sustained work load and duration of exercise (measured by a bicycle ergometer) versus the placebo (p less than 0.05). In both cases, however, they did not find any significant difference between propranolol and diltiazem. ST segment depression was decreased by both drugs (-1.73 +/- 0.95, baseline, vs -0.94 +/- 1.01, propranolol, and -0.95 +/- 0.76, diltiazem, p less than 0.5, for both). Long-term management of stable angina on effort therefore, can be usefully performed using propranolol or diltiazem.