LEFT-VENTRICULAR SHAPE DEFORMATION AND MITRAL-VALVE PROLAPSE IN CHRONIC PULMONARY-HYPERTENSION

Mitral valve prolapse (MVP) has been described in patients with right ventricular pressure or volume overload. The frequency of this phenome non and its relationship to left ventricular shape and mitral valve an nulus size, as well as its reversibility in chronic pulmonary hyperten sion, are poorly understood. We have observed an increased frequency o f MVP in a patient population with chronic thromboembolic pulmonary hy pertension that often resolves after thromboendarterectomy and reducti on of pulmonary hypertension. To further evaluate the relationship bet ween MVP and left ventricular shape in pulmonary hypertension, we stud ied 51 consecutive patients undergoing surgery for thromboembolic pulm onary hypertension. Echocardiographic features including interventricu lar septal position, as measured by an eccentricity index, left ventri cular size, and several mitral valve annulus dimensions were evaluated prior to surgery and during the postoperative hospitalization period. The pulmonary artery systolic pressure was elevated for all patients prior to surgery, 87 +/- 21 mmHg (mean +/- SD). Twelve patients (23.5% ) had MVP before surgery, which resolved in ten patients postoperative ly. In addition, one patient whose pulmonary hypertension improved lit tle, developed MVP postoperatively. Those patients with MVP had a grea ter pulmonary artery pressure preoperatively than those without MVP (1 02 +/- 19 vs 84 +/- 21 mmHg). The eccentricity index for those patient s with MVP (1.68 +/- 0.2) was greater than for those with no MVP (1.53 +/- 0.37). No significant differences were noted between groups with MVP and without MVP according to all mitral annulus dimensions or left ventricular chamber areas. Postoperatively, eccentricity index decrea sed significantly in both those with MVP and without MVP (1.29 +/- 0.1 8 and 1.20 +/- 0.15, respectively) as did pulmonary artery systolic pr essure (67 +/- 22 and 47 +/- 13 mmHg, respectively). Mitral valve prol apse in chronic pulmonary hypertension occurs frequently and is noted particularly in those patients with the most severe pulmonary hyperten sion. It appears that deformation of the left ventricle is associated with echocardiographic MVP and that reduction of pulmonary hypertensio n reverses this deformation and allows for resolution of MVP.