[The infundibular septum in congenital heart defects. Morphologico-angiocardiographic study of the double-outlet heart ventricle].

The authors investigated the infundibular septum in 40 archival heart preparations with a double outlet right ventricle. They compared the post-mortem findings with the previous angiocardiographic examination and the skiagram of the preparation made post mortem. They present also the corresponding findings obtained by echocardiography. The infundibular septum was in all instances the dominating intracardiac structure influencing the direction of the blood flow from the ventricles into outflow tracts in the direction towards the large arteries. In 15 instances the infundibular septum was shifted in an anterosuperior direction beneath the orifice of the pulmonary artery and it derived the blood current from the left ventricle through the defect in the ventricular septum into the aorta. The restricted blood flow through the aorta led to its hypoplasia, which in 11 instances was associated with coarctation or interruption of the aorta. In seven instances of posteroinferior shift the infundibular septum was straight. These cases were associated with coarctation or interruption of the aorta. In ventricular septum and with stenosis of the pulmonary artery. Based on these findings the authors assume that the shift of the infundibular septum in a double outlet right ventricle has a decisive position as regards haemodynamic manifestations of the defect and in the development of outflow tracts and large arteries. Last not least, information on the infundibular septum is also important for surgery of the defect.