[Ventricular-infundibular morphology in visceral heterotaxia with left isomerism. An echocardiographic-angiocardiographic study]

We report 2D-echocardiographic and angiocardiographic assessment of 28 cases of visceral heterotaxia with left atrial isomerism, with particular emphasis on infundibular ventricular morphology. Ventricular D-loop was present in 15 cases (52.6%), and ventricular L-loop in 13 (46.4%); 25/48 patients had concordant ventricular loop and cardiac position (89.3%). In 18 patients (64.3%) there were 2 balanced ventricles; of the other 10 patients, 9 (32.1%) presented right and 1 (3.6%) left ventricular dominance. Ventricular septal defect was present in 12 cases (42.8%). Ventriculo-arterial connections were concordant, with "normally related" great arteries in 9/15 cases with ventricular D-loop (60%). In these cases, ventricular morphology, connections and relations of the great arteries were typical of situs solitus. In the remaining 6 patients there was double-outlet right ventricle, also with normally related great arteries. In 12/13 cases (92.3%) with ventricular L-loop ventriculo-arterial connections were concordant with "mirror image normally related" great arteries. In these cases, ventricular morphology, connections and relations of the great arteries were typical of situs inversus. In one patient there was double-outlet right ventricle, also with mirror image normally related great arteries. Twelve patients (42.8%) had pulmonary stenosis and 5 had a systemic outflow obstruction (17.8%). From these observations we conclude that ventriculo-infundibular morphology, either of situs solitus-type or of situs inversus-type, is a typical anatomical feature of left atrial isomerism. These results may have important implications in the diagnosis and in the surgical management of patients with left atrial isomerism.