Pulmonary diffusion of carbon monoxide in patients with mitral stenosis

OBJECTIVE: The aim of our work has been the study of CO diffusion capacity in mitral valve stenosis patients. METHOD: We have studied 15 control subjects and 15 patients with mitral valve stenosis. We performed spirometry study and CO pulmonary diffusion tests (DLCO) by single breath method to determine two components: pulmonary capillary blood volume (Vc) and membrane diffusion factor (Dm). In addition, in mitral valve stenosis patients we performed a ecocardiography-doppler study. RESULTS: The mitral valve stenosis group had higher values of DLCO and Vc and a lower ratio of Dm/Vc than the control group. There is a negative correlation between Vc and the mitral valve area (r = -0.63; p = 0.037). We do not find any another correlation between the rest of ecocardiography doppler parameters and lung function test variables that we have measured. We have not found any differences between both groups in Dm. CONCLUSIONS: Mitral valve stenosis patients present a increase of CO pulmonary diffusion capacity and pulmonary capillary blood volume without changes in membrane diffusion factor.