Left Ventricular Function, Metabolism, and Blood Flow in Chronic Cor Pulmonale

Left ventricular function, oxidative metabolism, and coronary blood flow were evaluated in 11 patients with chronic cor pulmonale (mean age 53 years) at rest and during stress, and compared with 11 normal subjects (mean age 29 years) studied under similar conditions. The left ventricles of patients with chronic cor pulmonale were normal in regard to contractile state, preload, afterload, coronary blood flow, and myocardial oxidative metabolism. However, the mean cardiac index, stroke volume, stroke work, and left ventricular ejection fraction were below normal, and end-systolic volume was elevated. These differences in performance are consistent with the older mean age of the patients. An alternative explanation is the limit placed on right ventricular stroke volume by the increased afterload (pulmonary vascular resistance). Allowance for these factors permits the conclusion that the left ventricles of patients with chronic cor pulmonale are normal unless involved by a second disease process.