The effect of pindolol and isosorbide dinitrate and their combination on exercise tolerance and ECG changes in angina...

The effect of placebo, isosorbide dinitrate (ISDN) (5 mg orally), pindolol (1.0 mg i.v.) and the combination of ISDN and pindolol was tested in 12 patients with stable, exercise-induced angina pectoris and normal resting ECG. A graded submaximal exercise test was performed on a bicycle ergometer 30 min after medication. All patients had ST depression during and shortly after exercise. ISDN and pindolol increased exercise tolerance to a similar degree but through different mechanisms. Pindolol decreased heart rate and markedly reduced ST depression in the ECG, while ISDN had no effect on ECG changes. The combination of ISDN and pindolol was superior to either drug alone in increasing exercise tolerance in angina pectoris.