Right ventricular pressure-volume relations in chronic lung disease.

Thirty-four patients with chronic lung disease in stable condition were studied at supine rest (RS), at rest with the legs raised (LR), and during two levels of exercise: E1, 0 or 20 W, E2, 20 or 40 W. Five patients had normal spirometry (group 1), six patients had normal vital capacity but FEV1/VC below 70% (group 2), and 23 patients had VC below 95% of normal and FEV1/VC below 70% (group 3); group 3 was subdivided into group 3a (n = 14) without, and group 3b (n = 9) with a history of right heart failure (RHF). Right ventricular end-diastolic (RVEDV) and end-systolic (RVESV) volumes were computed from stroke volume and right ventricular ejection fraction (RVEF). RVEF at rest was correlated with lung function variables. Changes in RVEF from LR to E2 were normal, i.e. above 0.05, except for in group 3b, where RVEF did not increase with exercise. Relation between RVESV and pressure, and changes in stroke volume with RVEDV from LR to E2 were also abnormal in group 3b. These results show that in patients with chronic lung disease RVEF at rest reflects lung function, whereas its adaptation to exercise is impaired only in patients who have experienced RHF episodes.