Effect of nitroglycerin ointment on hemodynamics in patients with mitral insufficiency.

A reduction in impedance or afterload produces beneficial hemodynamic effects in patients with mitral regurgitation. This mechanism has been studied via intravenous infusion of nitroprusside, phentolamine, and hydralazine. But there is little information on the effect of nitroglycerin ointment in patients with mitral insufficiency. Thus 6 patients with mitral insufficiency underwent right and left heart catheterization. After the control hemodynamic measurements were recorded, a 2 1/2-inch strip of 2% nitroglycerin ointment was applied to the chest for half an hour. Pressure recordings and cardiac output were then repeated. The control cardiac index fell from 2.79 to a treatment value of 2.05 L/min/m2 (P < 0.01), while the stroke index also decreased from 29 to 22 ml/beat/m2 (P < 0.05). There was a nonsignificant increase in peripheral resistance. Thus nitroglycerin ointment can be detrimental when given to patients with mitral insufficiency.