[Sustained effect of nitroglycerin ointment on exercise tolerance in patients with effort angina (author's transl)]

The effect on exercise tolerance of nitroglycerin (NTG) ointment was studied by exercise test on bicycle ergometer in a selected group of patients with effort angina and angiographically proven critical coronary lesions. NTG ointment (15 mg) and placebo were administered in a double-blind cross-over randomized trial on two consecutive days; exercise test was carried out before the administration of NTG ointment and placebo, and repeated after one hour, 2 and 1/2 hours and 4 hours. Compared to control and placebo tests, NTG ointment produced a highly significant increase of duration of exercise and of total work load in all tests, as well as a significant decrease of maximal ST segment depression. After NTG ointment administration resting systolic blood pressure showed a significant decrease after one hour, 2 and 1/2 hours and 4 hours, resting heart rate a significant increase after 2 and 1/2 and 4 hours, and peak exercise heart rate a significant increase after 4 hours. Double product at rest was unaffected by NTG ointment, while at peak exercise it showed a significant increase only after 4 hours. Our data show that in patients with effort angina NTG ointment produces an important increase of exercise capacity which persists at least for 4 hours after the administration. Therefore NTG ointment seems to be of high value in the treatment of effort angina.