Partial improvement in pulmonary function after successful percutaneous balloon mitral valvotomy

Study objectives: This study was performed to assess the changes in pulmona ry function after a successful percutaneous balloon mitral valvotomy (PBMV) in 23 consecutive patients with symptomatic mitral stenosis. Methods and results: Lung function preprocedure and postprocedure were eval uated by spirometric flow, static pulmonary volumes, and diffusion capacity of the lung for carbon monoxide (DLCO), At baseline, a reduction in small airways flow (maximal expiratory flow at 50% of vital capacity, 70 +/- 29% of predicted value; maximal expiratory flow at 25% of vital capacity, 55 +/ - 26% of predicted value) and an increase in DLCO (118 +/- 29%) and Krough Index (KCO; 123 +/- 29% of predicted value) were observed. PBMV caused an i mprovement in hemodynamic parameters with an increase in mitral valve area (from 1.0 +/- 0.3 to 1.9 +/- 0.5 cm(2); p < 0.001) and a decrease in left a trial pressure (from 17 +/- 3 to 12 +/- 5 mm Hg; p < 0.001), These changes were associated with a significant increase in FVC (from 2.8 +/- 0.84 to 2. 9 +/- 0.80 L; p < 0.05) and in FEV1 (from 2.2 +/- 0.72 to 2.3 +/- 0.68 L; p < 0.05). A decrease in DLCO was obsened after PBMV (from 26.7 +/- 7 to 22. 5 +/- 5.4 ml/min/mm Hg; p < 0.001; and KCO, from 6.2 +/- 1.4 to 5.2 +/- 1.2 ml/min/mm Hg/L; p < 0.001). No significant changes in small airways flow w ere detected, suggesting only a partial improvement in pulmonary congestion . Conclusion: We conclude that the initial impairment of lung function in pat ients with symptomatic mitral stenosis is only partially ameliorated by PBM V.