A Dynamic Electrocardiographic Concept Useful in the Diagnosis of Cor Pulmonale

Abstract

The results of a survey of 200 patients with chronic obstructive pulmonary disease (COPD) revealed that the electrocardiographic criteria used in the past are relatively poor delineators of cor pulmonale in COPD, either in its early or late stages. The study offers a dynamic concept designed to aid in discovering right ventricular (RV) complications in COPD-the coupling of arterial blood gas analysis and four electrocardiographic fluctuations which signal RV abnormality. Where arterial O ₂ saturation fell below 85% and pulmonary artery mean pressure (PA _m ) was 25 mm Hg or greater, one or more of these four fluctuations were seen in patients with cor pulmonale: (1) a rightward shift of the mean QRS axis of 30° or more; (2) T-wave abnormalities in right V leads; (3) ST depressions in leads II, III, and aV _F ; and (4) transitory right bundle-branch block. With recovery of better arterial saturation and decrease in PA _m they subsided. Thus, a clinical appraisal of patients with COPD should include serial analyses of arterial blood gas plus serial electrocardiograms if early (and hence reversible) RV abnormality and cor pulmonale are to be uncovered.