RIGHT VENTRICULAR PERFORMANCE AND CENTRAL CIRCULATORY HEMODYNAMICS DURING UPRIGHT EXERCISE IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY-DISEASE

Abstract

A combined hemodynamic and radionuclide approach was used to evaluate right ventricular performance during upright exercise in 12 male patients with chronic obstructive pulmonary disease. To assess intrathoracic pressure influence on hemodynamic parameters, pleural pressure was measured using an esophageal balloon. Mean age was 58.5 .+-. 6.7 yr (.+-. SD) and all had dyspnea on physical exertion. For the group, forced expiratory volume in 1 S(FEV1) was 1.04 .+-. 0.40 l and arterial O2 tension (PaO2) was 77 .+-. 11 mmHg. During steady-state upright exercise on the bicycle ergometer at 58% of maximal O2 consumption (.ovrhdot.VO2 max) mean pulmonary artery pressure (.hivin.Ppa) and pulmonary vascular resistance index (PVRI) increased significantly: right ventricular ejection fraction (RVEF) failed to augment appropriately (< 5% increase); and right ventricular end-diastolic volume index (RVEDVI) increased significantly, whereas right ventricular end-systolic volume index (RVESVI) did not change. A diminished pulmonary vascular bed, the change in PaO2 and possibly increased alveolar pressure appeared to contribute to the increased right ventricle load. Both RVEDVI and RVESVI were significantly correlated with .hivin.Ppa at rest and during exercise. In 2 of the 12 patients, stroke volume index and left ventricular end-diastolic volume index showed minimal change with exercise, .ovrhdot.VO2 max was correlated with the FEV1 (r = 0.75; P = 0.01) as well as resting (r = -0.60; P = 0.02) and exercise (r = -0.61; P = 0.02) PVRI. Exercise performance may be limited by right ventricular dysfunction in addition to respiratory impairment in some patients with chronic airway disease.