Electro‐vectorcardiographic demonstration of bifascicular block associated with ventricular preexcitation

Down syndrome occurs more frequently in the offsprings of older pregnant women and may be associated with atrioventricular septal defect. This refers to a broad spectrum of malformations characterized by a deficiency of the atrioventricular septum and abnormalities of the atrioventricular valves caused by an abnormal fusion of the superior and inferior endocardial cushions with the midportion of the atrial septum and the muscular portion of the ventricular septum.