Defecto septal atrioventricular. Estudio anatomopatológico y correlación embriológica / Atrioventricular septal defect. Anatomopathologic study and embryological correlation

Atrioventricular septal defect is a complex congenital heart disease in which cardiac septation is deficient especially at atrioventricular and ventricular levels. The anatomopathologic experience at the National Institute of Cardiology [quot ]Ignacio Chávez[quot ] is described; an anatomo-embryological correlation was made to gain an insight of the pathogenesis. Seventy hearts were analyzed morphologically with the sequential segmentary system. Atrial situs, connections of cardiac segments, cardiac septa, septal defects, ventricular geometry, fibrous skeleton and associated anomalies were determined. Histologic sections of chick embryonic hearts were analyzed and compared with stages of human heart development, serving as basis to elaborate the anatomo-embryological correlation. Seventy hearts had a common atrioventricular valve and five had two separated atrioventricular valves. The ventricular septal defect was open in the first type and closed in the second; the other features were the same in both. This cardiopathy is shown as a broad spectrum of anatomical variations. The morphological knowledge of this cardiac malformation is useful to understand the physiopathology, to make a precise clinical diagnosis, and to give the best orientation to the surgeon. Delay in the development of the atrioventricular cushions is emphasized as the pathogenetic explanation for this type of congenital heart disease.

Defecto septal atrial. Estudio morfopatológico, embriológico / Atrial septal defect. A morphopathological and embryological study

To contribute to a better understanding of the morphopathology of atrial septal defects (ASD), we describe and classify topographically a series of hearts obtained from necropsies. We performed an anatomo-embryological correlation to gain insight on the pathogenesis of this type of congenital heart disease. Seventy-one hearts with ASD and twenty-three normal hearts with patent foramen ovale from the collection at the Instituto Nacional de Cardiologia lgnacio Chavez were studied morphologically; segmental sequential analysis was used. The topography of the interatrial septum was determined on the basis of the structures related to it in order to classify the ASD. The FS area was projected on the right septal surface using pins. To stablish the anatomo-embryological correlation, the ASD's anatomy was compared with the embryological processes that take place in atrial septation. The most frequent ASD was the OO type (FS) with 64.78%, followed by common atrium, true FS, FP, superior and inferior sinus venosus, types each one with 2.81% and one coronary sinus venosus type (1.40%). The FS area was projected below the superior vena cava. The morphologically and topographically knowledge of atrial septal defect is useful to interpret the imaging studies of this cardiopathy and is basic for the surgeon and the interventionist cardiologist. Abnormal apoptosis and retarded developmental growth are proposed as pathogenic mechanisms.