Aortic valve prolapse associated with outlet-type ventricular septal defect.

BACKGROUND: Aortic valve prolapse is frequently associated with juxta-arterial ventricular septal defect. The significance of its association with other outlet types of ventricular septal defect, however, remains unclear.

METHODS: From 1987 to 2002, 677 patients (male:female ratio, 424:253) who received surgical repair for ventricular septal defect extending to the outlet septum were reviewed. Based on surgical findings, ventricular septal defects were classified as juxta-arterial, perimembranous outlet, or muscular outlet type.

RESULTS: Aortic valve prolapse occurred in 373 of 677 patients (57.2%) with 209 juxta-arterial, 103 perimembranous outlet, and 61 muscular outlet type. Significant aortic regurgitation developed in 51 of 373 (14%). Among 252 patients with regular follow-up, the mean onset ages of aortic valve prolapse in juxta-arterial, perimembranous outlet, and muscular outlet type were 4.9, 5.0, and 5.1 years, respectively (no statistical difference). The presence of larger shunt and probably anterior malalignment predicted an earlier onset of aortic valve prolapse. Perimembranous outlet and muscular outlet type ventricular septal defect were frequently associated with infundibular hypertrophy and subaortic ridge, and perimembranous outlet type was associated with anterior septal malalignment. In juxta-arterial ventricular septal defect and ventricular septal defect with anterior malalignment, prolapsed cusp was always the right coronary cusp, but noncoronary cusp involvement was also common in perimembranous outlet type (17 of 103, 16.5%).

CONCLUSIONS: The association with anterior septal malalignment, infundibular stenosis and subaortic ridge is related to the location of the outlet ventricular septal defect. The age of onset of aortic valve prolapse in each type was quite similar, and a larger shunt may predict an earlier onset.