STUDIES OF THE PULMONARY CIRCULATION AT REST AND DURING EXERCISE IN NORMAL INDIVIDUALS AND IN PATIENTS WITH CHRONIC PULMONARY DISEASE’t 2

Studies of the cardiac output of normal individuals during muscular exercise have been made by several investigators (l-5). Systemic blood pressure has likewise been measured during exercise, making possible the calculation of peripheral resistance and the work of the left ventricle. Until recently (5), such information was not available in the case of the right ventricle because pulmonary arterial pressure was not known By using the technic of pulmonary artery catheterization, both cardiac output and pulmonary arterial pressure can be determined during exercise, and pulmonary resistance and the work of the right ventricle can be calculated. This report deals with such studies on three normal individuals and eight patients with chronic pulmonary disease from whom data were obtained at rest and during exericse. In some patients with chronic pulmonary disease the pulmonary arterial pressure and cardiac output at rest are normal (6,7), and it is of interest to determine whether the pulmonary arterial pressure becomes abnormally high during exercise. In these patients and in others who show high pulmonary arterial pressure at rest it is of importance from the point of view of estimating their disability to determine whether there is abnormally low cardiac output or abnormally high work of the right ventricle during exercise.