[Phono- and echocardiographic studies of the genesis of mitral valve prolapse in patients with funnel chest].

Two-dimensional echocardiograms (2-DE) and phonocardiograms (PCG) were used to clarify the genesis of mitral valve prolapse (MVP) and mitral regurgitation (MR) in 44 patients with funnel chest. These patients were categorized in three groups on the basis of the fronto-sagittal index (FSI) as determined from chest radiographs; 17 as mild, 15 as moderate and 12 as severe funnel chest. Their ages ranged from 5 to 65 years and averaged 24 years. MVP was diagnosed using the long-axis view of the 2-DE, and MR was diagnosed phonocardiographically including provocative test using angiotensin II. The results were as follows: In 44 patients with funnel chest, 20 (45%) had MVP and 15 (34%) had MR, respectively. The incidence of MVP increased directly in proportion to the severity of index, but the incidence of MR did not. In the short-axis view of the left ventricle at the level of the papillary muscles, there was more marked flattening of the interventricular septum than of the left ventricular posterior wall, resulting in deformity of the left ventricular geometry. A distortion index (DI) was used to quantify the degree of distortion of left ventricular shape, calculated as follows: DI = (R-r)/r, where R and r were radii of the curvatures of the interventricular septum and the left ventricular posterior wall, respectively. The DI in end-diastole (DId) and end-systole (DIs) increased in proportion to the severity of funnel chest. Patients were subdivided into four groups on the basis of DId. Incidence of MVP increased in proportion to the degree of distortion of the left ventricular shape. There was, however, no significant difference in the incidence of MR among the four groups. Patients were subdivided; one group of 13 under 14 years of age; another, 31 over 15 years old. The incidence was much higher in the latter than the former, but the incidence of MVP increased in proportion to the severity of funnel chest in both groups. MR was complicated by MR in nearly all cases in the latter group, but none had MR in the former. The DI of patients, whose FSI improved with surgery, apparently improved in addition to the disappearance and/or improvement of their MVP and MR. However, patients whose FSI did not improve with surgery showed little change in DI and persistence of MVP and/or MR.(ABSTRACT TRUNCATED AT 400 WORDS)