[Aneurysm of the membranous septum associated with interventricular patency. Echocardiographic study].

It has been documented by others that spontaneous closure or diminution in size of membranous ventricular septal defect is often associated with aneurysmal formation of the membranous septum. In a series of 51 patients, who underwent cardiac catheterization and cineangiocardiography for evaluation of the severity of a ventricular septal defect, 7 patients showed an aneurysm of the membranous interventricular septum (VSA) associated with a small ventricular septal defect (VSD). M-mode echocardiography was useful in the detection of VSA in 6 of them. Echocardiographic findings were not uniform in all cases. In most instances they consisted of linear echoes, that seemed to come off from the base of the interventricular septum and to protrude within the right ventricle in systole; the echoes from the VSA showed a coarse fluttering. Even if errors can be minimized by a correct technique, anomalous echoes from the VSA might however be confused with those of other anatomical structures (aortic root, tricuspid valve, etc.). M-mode echocardiography seems to be useful for the followup of patients with membranous VSD. The detection of VSA by ultrasonic means should suggest a good prognosis for VSD, possibly avoiding the need for repeat invasive studies.