EFFECTS OF INHALATION OF 100 PERCENT OXYGEN ON MYOCARDIAL LACTATE METABOLISM IN CORONARY HEART DISEASE

Hemodynamic changes occurred after administration of 100 per cent oxygen to subjects with normal coronary arteries and to patients with coronary artery disease as demonstrated by coronary arteriograms. Cardiac index decreased but mean arterial pressure and peripheral vascular resistance increased slightly. Left ventricular work was decreased in normal subjects and in patients with less than 50 per cent narrowing of the coronary vessels; it remained unchanged in patients with significant coronary artery disease. On the other hand, the arterial oxygen content and coronary arteriovenous oxygen difference were significantly increased during inhalation of oxygen. In patients with significant coronary artery disease, especially in the presence of severe triple vessel disease, abnormal lactate changes were produced or accentuated during the administration of oxygen. The significance of these changes are discussed. Further studies are needed to assess the indications for oxygen therapy in coronary heart disease. © 1969.