HAeMODYNAMIC CONSEQUENCES OF CORONARY HEART DISEASE WITH OBSERVATIONS DURING ANGINAL PAIN AND ON THE EFFECT OF NITROGLYCERINE

Abstract

Twenty-four patients (20 had ecg signs and a history of myocardial infarction), without signs of valvular disease or elevated blood pressure, were studied by cardiac catheterization during exercise and at rest. In 6 patients, whose main symptom was dyspnea and who had enlarged hearts, there was an increase in pulmonary capillary pressure (PCPm) even at rest with a parallel increase in pulmonary artery pressure (PAPm). Of 11 patients with previous myocardial infarction with normal size hearts whose chief symptom was angina, only one had an abnormally elevated PCPm at rest but 5 had pressures in the upper limits of normal (11-12 mm Hg). Of 8 patients exercised, 6 showed abnormal increase of pulmonary vascular pressure and all but one had anginal pain during the exercise. All showed an increase in cardiac output (CO) during exercise as in contradistinction to the previous group. Patients, without previous infarction whose complaint was angina had normal hemodynamics at rest but developed an abnormally raised PCPm during exercise. The effect of nitroglycerine on 4 patients at rest, 2 with and 2 without previous myocardial infarction, was to reduce PCPm by 1-2 mm Hg and the peripheral systolic blood pressure by 0-10 mm Hg. During moderate exercise after nitroglycerine, there are no systemic changes in CO but the same amount of exercise that before administration markedly increased PCPm could then be tolerated with the PCPm remaining within normal limits.