Right ventricular performance and central circulatory hemodynamics during upright exercise in patients with chronic obstructive pulmonary disease.

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 the influence of intrathoracic pressure 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 one second (FEV1) was 1.04 +/- 0.40 L and arterial oxygen-tension (PaO2) was 77 +/- 11 mmHg. During steady-state, upright exercise on the bicycle ergometer at 58% of maximal oxygen consumption (VO2 max): (1) mean pulmonary artery pressure (Ppa) and pulmonary vascular resistance index (PVRI) increased significantly; (2) right ventricular ejection fraction (RVEF) failed to augment appropriately (less than 5% increase); and (3) 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 load placed on the right ventricle. Both RVEDVI and RVESVI were significantly correlated with 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. VO2max 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. These results suggest that exercise performance may be limited by right ventricular dysfunction in addition to respiratory impairment in some patients with chronic airway disease.