RESUMO
Right and left ventricular ejection fraction (RVEF; LVEF) were determined in patients with severe chronic pulmonary disease (mean +/- SEM [FEV1 percent predicted 36 +/- 3%; PaO2: 64 +/- 3 mm Hg]), utilizing first pass radionuclide angiocardiography. RVEF and LVEF were measured at rest and again during upright bicycle exercise while patients breathed room air, and again during low flow oxygen (O2) administration. Mean RVEF was abnormal (less than 45%) at rest and did not increase with exercise while subjects breathed room air (44 +/- 2 percent vs 44 +/- 3 percent, P = ns), but improved significantly during exercise while patients breathed O2 (45 +/- 5 percent vs 51 +/- 3 percent, P less than .05). Breathing room air, RV exercise ejection fraction was abnormal (less than 5 percent increase in absolute RVEF) in 15 of 18 patients, but only 5 of 10 patients were abnormal during O2 administration. LVEF at rest was normal in all subjects. These data suggest: 1) RV exercise ejection fraction is abnormal in most patients with chronic pulmonary disease; 2) while low flow O2 does not alter RV performance at rest, it improves RV exercise ejection fraction in some patients.
