[Interauricular communication and mitral prolapse. An echocardiographic and angiographic study].

The association of atrial septal defect (ASD) and mitral valve prolapse (MVP) is well known but its precise incidence has not yet been established. Most previous publications have only been angiographic studies and the diagnostic criteria of MVP were, therefore, controversial. In this study, 61 consecutive patients, adults and children, underwent M mode echocardiography and cardiac catheterisation with cineangiography. In the adult group echocardiographic MVP was observed in one of 23 patients with secundum ASD. These findings were confirmed on angiography in addition, four other cases were observed in patients without systolic clicks or pansystolic or late systolic murmurs. MVP was observed in four out of 27 children with secundum ASD on M mode echocardiography and all cases were confirmed at angiography. In contrast to the adult group, no additional cases were demonstrated. Three out of 11 patients with ostium primum defects had MVP at echo and/or angiography, a finding which was probably related to the common atrioventricular canal. Follow-up echocardiography 6 weeks after surgical repair of ASD showed persistent but less marked MVP in all cases. Echocardiographic evidence of MVP was therefore demonstrated in 5 out of 50 patients (10%) with secundum ASD. It was more common in children (15%) than in adults (4%). These results differ from those previously published, probably because of differences in method (use of echo and angiography), diagnostic criteria, size of atrial shunt and the incidence of associated mitral regurgitation. The prevalence of MVP in patients with ASD may have been overestimated in previous publications.