Ko. Burleson et al., LEFT-VENTRICULAR SHAPE DEFORMATION AND MITRAL-VALVE PROLAPSE IN CHRONIC PULMONARY-HYPERTENSION, Echocardiography, 11(6), 1994, pp. 537-545
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.