Improvement in left ventricular ejection fraction after surgery for mitral stenosis.

It is recognised that patients with mitral stenosis may have impaired left ventricular function. The reasons for this are speculative and the effects of surgical relief of stenosis on left ventricular function unknown. Five patients showed dramatic improvement in left ventricular ejection fraction after surgery. Possible reasons include altered loading conditions, changes in ventricular interaction and partial restoration of the normal anatomical structure of the mitral valve complex.