ACETYLCHOLINE AND THE PULMONARY CIRCULATION IN MITRAL VALVULAR DISEASE

Abstract

In a study of the nature of pulmonary hypertension in 13 patients with mitral stenosis, studies of the effect of acetylcholine infusion on various parameters of hemodynamics were made during rest and during exercise. At rest, following the infusion, the cardiac output remained the same or rose slightly while pulmonary artery pressure and O2 saturation decreased. With exercise, the infusion caused essentially the same changes; and in patients in whom the CO2 partial pressures of arterial blood were determined, acetylcholine caused a slight decrease. The probable action of acetylcholine in these patients is to increase the intrapulmonary shunting of blood.