[Aneurysm of the membraneous portion of the ventricular septum].

The presented analysis is based on the observations of 13 cases of rare congenital pathology--aneurysms of the membranous portion of the ventricular septum, as well as on the pertinent literature. The majority of the patients were subjected to intracardiac methods of examination; in 5 cases autopsy data are available. The anatomy of such aneurysms is described, the possible causes of its development are discussed, the haemodynamics is studied, as well as the heart diseases the aneurysm was accompanying.