Prolonged salutary effects of isosorbide dinitrate and nitroglycerin ointment on regional left ventricular function.

To assess the long-term effects of orally and topically administered nitrates on left ventricular function, 11 patients with previous myocardial infarction were studied with use of isosorbide dinitrate, 20 mg orally, nitroglycerin ointment, 12.5 to 40 mg and placebo ointment. Both nitrates produced a sustained decrease in systolic blood pressure and estimated left ventricular wall stress but no change in heart rate during 4 hours of study. The triple product of heart rate, systolic blood pressure and left ventricular ejection time decreased by 21 percent after administration of isosorbide dinitrate (P < 0.001) and 19 percent after administration of nitroglycerin ointment (P < 0.001). The echocardiographic left ventricular end-diastolic dimension decreased significantly after isosorbide dinitrate (from 52.4 to 49.2 mm at 2 hours, P < 0.01) and nitroglycerin ointment (from 52.4 to 50.5 mm, P < 0.01). The end-systolic dimension was similarly reduced. Left ventricular sites showing abnormally small excursion (less than 3 mm) on wall motion videotracking showed improved motion after the administration of each nitrate, and the velocity of systolic inward motion was consistently increased after each. Thus, determinants of myocardial oxygen consumption, such as systolic blood pressure, left ventricular ejection time, left ventricular size and triple product appear to be consistently reduced for at least 4 hours after administration of isosorbide dinitrate and nitroglycerin ointment, and impairment of left ventricular wall motion appears to be significantly decreased.