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 phenomenon and its relationship to left ventricular shape and mitral valve annulus size, as well as its reversibility in chronic pulmonary hypertension, are poorly understood. We have observed an increased frequency of MVP in a patient population with chronic thromboembolic pulmonary hypertension that often resolves after thromboendarterectomy and reduction of pulmonary hypertension. To further evaluate the relationship between MVP and left ventricular shape in pulmonary hypertension, we studied 51 consecutive patients undergoing surgery for thromboembolic pulmonary hypertension. Echocardiographic features including interventricular septal position, as measured by an eccentricity index, left ventricular 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 postoperatively. In addition, one patient whose pulmonary hypertension improved little, developed MVP postoperatively. Those patients with MVP had a greater pulmonary artery pressure preoperatively than those without MVP (102 +/- 19 vs 84 +/- 21 mmHg). The eccentricity index for those patients 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 decreased significantly in both those with MVP and without MVP (1.29 +/- 0.18 and 1.20 +/- 0.15, respectively) as did pulmonary artery systolic pressure (67 +/- 22 and 47 +/- 13 mmHg, respectively). Mitral valve prolapse in chronic pulmonary hypertension occurs frequently and is noted particularly in those patients with the most severe pulmonary hypertension. It appears that deformation of the left ventricle is associated with echocardiographic MVP and that reduction of pulmonary hypertension reverses this deformation and allows for resolution of MVP.