RESUMO
INTRODUCTION: It has been postulated that there is a morphogenetic relation between the atrioventricular septal defect (AVSD) type A of Rastelli and the type of two separated orifices, this so called partial forms, existent between both types a spectrum of anatomical forms in which interchordal spaces determinate the ventricular septal defects (VSD) size to forms in which the VSD is closed by fusion of the left septal valves to the crest of ventricular septum. METHODS: We present five patients which illustrates the variability of the atrioventricular defect by means of two dimensional and three-dimensional echocardiography. In each case was made a transesophagic echocardiogram using three-dimensional reconstruction with an Echo-Scan system (4.0 TomTec Gmb version, Munich, Germany). RESULTS: It was observed the following spectrum of atrioventricular defect: one patient had a complete closure of the VSD by the insertion of the left septal valves to the interventricular septal crest. One patient has a partially closed VSD. The last 3 patients had a large VSD with a large shunt and high pulmonary pressure. In those patients in whom the VSD was completely or partially closed, the hemodynamic behavior depended of the interatrial shunt and the regurgitation of the atrioventricular valve. They didn't present pulmonary hypertension, what allowed them to be less symptomatic. CONCLUSIONS: The three-dimensional echocardiographic study of the spectrum of AVSD type A of Rastelli, defines accurately the valve components and septal structures, so we can understand the transition between complete and partial forms. This difference determines the clinical evolution of the patients.