[Duplication of the mitral and tricuspid valvular orifice. Study of 10 cases]

Ten patients with duplication of the atrioventricular valves were studied, nine of them with the double orifice located in the mitral valve and the other one in the tricuspid. In two cases the diameter of the secondary valve was the same as that of the normal valve, and in the other 8 cases, it was smaller; each had its own valvular apparatus with chordae tendinae attached to papillary muscles located in different sites. The principal malformation in nine was ostium primum. One of the cases with mitral duplication had pulmonary atresia, an association which has never before been published. In five patients regurgitation of the secondary orifice was present; the diagnosis was made during surgery in nine cases and at necropsy in one. The orifice was sutured in three cases because of regurgitation. Four patients died in the immediate post-operative period, including the one with pulmonary atresia. The other three had pulmonary hypertension. These findings agree with the literature. The etiological hypotheses are discussed and emphasis is given to the importance of the finding of a narrow jet of contrast material directed upward and to the right in the left angiocardiogram in frontal plane. The authors believe that this may be an important sign in diagnosing cases with ostium primum septal defect; taking into account the fact that double mitral orifice is the cause of valvular insufficiency, this can be the site of bacterial endocarditis and usually needs to be surgically closed.