[Mitral valve disease in infants. Anatomical and functional evaluation by echocardiography].

To describe the incidence of mitral valve abnormalities among infants aged 0 to 24 months, their anatomic features, site of lesion, severity and associated heart defects, the records of 3,583 such patients submitted for bi-dimensional ultrasound and pulsed Doppler cardiac studies by presumptive heart disease were analyzed. Mitral valve abnormalities were thus detected in 88 of these cases, and were also documented by clinical examination (n: 88), heart catheterization and angiocardiography (n: 11), surgery (n: 17) and necropsy (n: 2). Seventy five cases had additional heart disease, most commonly aortic stenosis (27%), aortic coarctaction (26%) and ventricular septal defects (43%). Papillary muscle deformities at the subvalvar mitral apparatus were considered to be the most frequent mechanism for congenital mitral stenosis (100%), and annulus dilatation was the most frequent cause of mitral insufficiency (49%). Relative incidences of mitral valve stenosis and insufficiency among the whole studied sample were 0.5% and 1.48% respectively. There was a rough correlation between Doppler transmital gradient or regurgitation jet area and the corresponding mitral valve abnormality. This kind of noninvasively obtained data about mitral architecture and function seems to be a very useful and sensitive guide to define and manage this patients.