Defecto septal atrial. Estudio morfopatológico, embriológico

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 cardiología "ignacio chávez" were studied morphologically; segmen-tal 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 00 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.