Left ventricular function in chronic obstructive pulmonary disease.

Left ventricular function was studied at rest and during post-extrasystolic potentiation (PESP) in 18 patients with chronic obstructive lung disease. The contractility indices were obtained from pressures recorded in the osovolumetric period and from volume variations during ejection. All patients were hypoxic; six of them had cor pulmonale (group B); the remaining 12 patients constituted group A. Left ventricular function was similar in both groups; it is concluded that right heart failure in cor pulmonale is not secondary to left ventricular failure. Left ventricle was hypertrophied and pump function altered, but left ventricular kinetics was normal or increased. Isovolumetric phase contractility indices were decreased; they may increase during PESP. Left ventricular compliance was altered due to left and right ventricular hypertrophy and to paradoxical movement of interventricular septum which impeded diastolic expansion of left ventricle. The impairment of left ventricular function seems to be related to both intrinsic (hypoxia, hypercapnia, hypertrophy) and extrinsic factors (right ventricular hypertrophy with deviation of interventricular septum, lowering of left ventricular preload).