Real-Time 3-Dimensional Transesophageal Echocardiography of the Atrioventricular Septal Defect

Abstract

Being able to view the morphological details of the heart malformation in any patient with the diagnosis of atrioventricular septal defect (AVSD) is invaluable in surgical planning, especially in the current era of modified 1-patch versus 2-patch techniques. Real-time 3-dimensional transesophageal echocardiography (RT 3D TEE) is a recently developed technique that allows real-time high-quality images akin to viewing the heart specimen. We present the principal pathomorphological features of AVSD as visualized by RT 3D TEE. The hallmark of AVSD is a common atrioventricular junction guarded by a common atrioventricular valve.1 In the normal heart, when seen from atrial perspective, the aortic valve is wedged between the mitral and tricuspid valve. In AVSD, because of the common AV junction, the aortic valve is in an “unwedged” position (Figure 1). The valve consists of 5 leaflets: the superior and inferior bridging leaflets, each of which overrides the ventricular septum, a left mural leaflet, a right anterior, and a right inferior leaflet (Figure 2). Whether the bridging leaflets are joined together distinguishes the complete form from the partial form. In partial AVSD (also termed “ostium primum ASD”), a tongue of leaflet tissue connects the bridging leaflets and the undersides of these leaflets …