Nitroglycerin reduces elevated left ventricular filling and pulmonary arterial pressures in resting patients with rheumatic valve disease and reduces symptoms when given over long periods to patients with
primary myocardial disease. To determine whether
nitroglycerin may prove effective therapeutically in ambulatory patients with
heart valve disease, its effects on hemodynamics and exercise capacity were studied in 11 severely symptomatic adults who were already receiving optimal treatment with digitalis and
diuretic agents. Seven had predominant mitral valve disease, one had predominant aortic insufficiency and three had equally severe mitral and
aortic valve disease. Maximal exercise capacity was assessed with graded treadmill exercise after placebo and after
nitroglycerin (0.5 mg sublingually) administered in random sequence to each patient. Exercise capacity (exercise time to limiting
fatigue or
dyspnea) increased from a mean of 8.3 minutes after placebo to 9.8 minutes after
nitroglycerin (P less than 0.005). Eight patients were studied hemodynamically during further intense treadmill exercise. Pulmonary arterial pressure was significantly lower (P less than 0.05) after
nitroglycerin than after placebo (mean 44 versus 56 mm Hg), but cardiac output was greater after
nitroglycerin (5.0 versus 4.6 liters/min, P less than 0.005). Thus,
nitroglycerin appears to increase exericse tolerance and improve the hemodynamic response to exercise in patients with
heart valve disease and may be valuable in the long-term pharmacologic
therapy of such patients.