THE ELECTROCARDIOGRAM IN ASPHYXIAL AND IN EMBOLIC ACUTE COR PULMONALE

Abstract

A comparison has been made of the electrocardiogram of 11 patients with acute respiratory failure, 8 with pulmonary embolism, and 4 with pulmonary embolism complicating chronic pulmonary disease. In acute respiratory failure the electrocardiogram characteristically shows sinus tachycardia, a P wave axis of + 70[degree] or more, extreme "clockwise rotation" (rS pattern in leads V5 to V7), and upright T waves in leads III and V2 to V7. A right atrial P wave is frequent. In acute respiratory failure, in contrast with pulmonary embolism, there is only rarely a Q wave in lead III, S-T segment depression in leads I and n, or T wave inversion in lead III or over the right praecordium. A dominant R wave in lead a VR and deep S waves in leads I and II are seen in both conditions, and in both the electrocardiographic signs tend to be transient. When pulmonary embolism complicates chronic pulmonary disease, the electrocardiogram often shows changes resembling those of acute respiratory failure, rather than those of pulmonary embolism. The term "acute asphyxial cor pulmonale" is proposed for the cardiovascular manifestations of acute respiratory failure.