Exercise First-Pass Radionuclide Assessment of Left and Right Ventricular Function and Valvular Regurgitation in Symptomatic Mitral Valve Prolapse

Abstract

The changes in right ventricular (RV) and left ventricular (LV) function and in regurgitant fractions on first-pass exercise radionuclide angiography (RNA) were assessed in 29 consecutive patients with symptomatic mitral valve prolapse (MVP).

The mean right ventricular ejection fraction (RVEF) was 35±8% at rest and 46±15% after exercise (p < 0.001). The mean left ventricular ejection fraction (LVEF) was 62 ± 11 % at rest and 74±13% after exercise (p < 0.001) . Seven of 29 patients had an abnormal RV response and 6 had an abnormal LV response. Eight had abnormal wall motion after exercise. A total of 12/29 patients (41 %) had one or more abnormalities.

The mean left-sided regurgitant fraction before exercise was 27±17% in 21/29 patients (72%) and 31±21% after exercise (p=ns) . An additional 5 pa tients (17%) developed left-sided regurgitation after exercise.

These fmdings indicate that wall motion abnormalities and abnormal RVEF and LVEF responses to exercise occur in symptomatic MVP patients. In addi tion, 26/29 (89.6%) had left-sided regurgitation after exercise.

Since the presence of a murmur did not correlate with the presence of mitral regurgitation by RNA, then symptomatic patients with MVP should have first- pass exercise RNA to assess the presence of regurgitation at rest and after exer cise. Antibiotic prophylaxis is recommended in MVP patients with systolic mur murs or with regurgitation. Since patients without murmurs can have regurgi tation, further study is necessary to determine the need for endocarditis pro phylaxis in these patients.