Early changes in pulmonary functions after mitral valve replacement

BACKGROUND: This study evaluates changes in pulmonary functions before and after mitral valve replacement (MVR). MATERIALS AND METHODS: Twenty-five patients with rheumatic mitral lesions who had undergone MVR were divided into three groups, based on New York Heart Association (NYHA) class. They were evaluated for changes in pulmonary functions, preoperatively and postoperatively at 1 week, 1 month and 3 months to find any improvements after MVR. RESULTS: Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow rates were universally found to be decreased preoperatively. Total lung capacity (TLC) and diffusion capacity (DLCO) were significantly reduced preoperatively in NYHA Class III and IV. The pulmonary functions further declined at 1 week after surgery. Except for FVC in NYHA Class IV (32.3% improvement, P < 0.05), the changes were statistically insignificant. CONCLUSIONS: Pulmonary functions deteriorate immediately after surgery and then recover gradually over a period of 3 months. However, they remain below the predicted values.