LEFT-VENTRICULAR FUNCTION IN CHRONIC MITRAL REGURGITATION - PREOPERATIVE AND POSTOPERATIVE COMPARISON

Objectives. The present study was designed to evaluate the effects of surgical procedure on left ventricular systolic and diastolic function in patients with mitral regurgitation, Background. Left ventricular systolic function has been shown to decline after operation in patients with chronic mitral regurgitation. Methods. Using simultaneous cineangiography and left ventricular micromanometry we evaluated left ventricular systolic and diastolic function in 14 patients with chronic mitral regurgitation both preoperatively and at an average of 22 months after operation. Eight patients underwent mitral valve reconstruction, and six had a valve replacement with interruption of the chordae tendineae. We compared these patients with 10 central subjects. Results. Preoperatively, patients with mitral regurgitation demonstrated normal global and regional left ventricular systolic function. Peak rate of diastolic filling was increased (p < 0.01), and passive chamber stiffness was decreased, compared with that in control subjects (p < 0.01), and there was normal myocardial stiffness. Postoperatively, systolic and diastolic function returned to normal in patients undergoing mitral valve reconstruction. In contrast, global systolic function was depressed in patients after valve replacement (p < 0.05), with regional dysfunction in the area of papillary muscle attachment (p < 0.01). Diastolic function was depressed in this group, with a prolonged time constant of pressure decay (p < 0.01) and a depressed rate of early diastolic filling and strain rate (p < 0.05). Passive elastic stiffness was within the normal range in all postoperative patients. Conclusions. The type of operation performed to correct chronic mitral regurgitation has an important effect on postoperative left ventricular function. Systolic and diastolic function are preserved after mitral valve reconstruction. Mitral valve replace ment with chordal interruption is associated with global and regional systolic dysfunction and early diastolic filling and relaxation abnormalities.