EXPERIMENTAL STUDIES ON REVERSIBILITY OF PULMONARY HYPERTENSION.

pulmonary arterial pressure and t is well known that elevation of microscopic pulmonary vascular changes occur from left-to-right shunts. In many instances both the pressure elevation and the vascular changes regress following closure of the shunt, while in others the pressure remains elevated presumably due to irreversible pulmonary vascular change. An experimental study was instituted to attempt to correlate the severity of the microscopic vascular lesions with the degree of pulmonary hypertension and to determine at which stage the vascular lesions become irreversible.