[Exercise echocardiography and clinical features in patients with mitral valve prolapse]

To assess left ventricular (LV) functional reserve and prognosis in patients (pts) with idiopathic mitral valve prolapse (MVP), we performed ergometer exercise echocardiography for 10 normal subjects and 30 MVP pts without or with mild mitral regurgitation (MR). These 30 pts were followed for 2-8 years (mean 4.5). Percent changes (delta%FS) of % fractional shortening (%FS) during exercise at initial study in MVP pts and normal subjects were 7 +/- 7 and 11 +/- 3%, respectively. Based on delta%FS, MVP pts were divided into two groups; Group I: 13 cases with delta%FS less than 5%, Group II: 17 cases with delta%FS greater than or equal to 5%. The incidence of cardiac symptoms was higher in Group I than in Group II (85 vs 41%, p less than 0.05). ST-T changes on standard 12 lead ECG and life-threatening arrhythmias on Holter ECG were more frequently observed in Group I (38 vs 18%, 58 vs 20%). During follow-up period, M-mode echo measurements did not change in Group II, but LV end-diastolic dimension, LV end-systolic dimension and left atrial dimension significantly increased (p less than 0.05, p less than 0.01, p less than 0.01, respectively), and %FS significantly decreased (p less than 0.01) in Group I without any changes of MR severity. Thus, some MVP pts with impaired cardiac reserve detected by exercise echo may develop progressive deterioration of cardiac function even without significant MR.