Double Outlet Right Ventricle

Abstract

Double outlet right ventricle is a rare congenital cardiac malformation that appears to result from lack of conotruncal inversion, failure of leftward conoventricular shift and persistance of a subaortic conus [1, 2]. The anomaly is classified into two categories: those hearts with and those without pulmonary stenosis [3, 4]. The obstruction to pulmonary blood flow may be either valvular, subvalular, supravalvular, or a combination of these [5]. The great arteries in double outlet right ventricle are either side by side (aorta on the right), d-malposed (aorta anterior and to the right of the pulmonary artery), 1-malposed (aorta anterior and to the left of the pulmonary artery), or normally related [6]. The persistence of a subaortic conus prevents the normal leftward shift of the aorta and aortic valve. Thus, the aorta remains to the right of the pulmonary artery and muscle tissue (bilateral conus) separates the mitral and tricuspid valves from the aortic valve and pulmonic valve (Figures 1 & 2). The anomaly is further classified by the position of the ventricular septal defect. The ventricular septal defect may be related to (1) the aortic valve (subaortic), (2) the pulmonic valve (subpulmonic) (TaussigBing anomaly), (3) to both semilunar valves (doubly committed) or (4) to neither semilunar valve (remote) [7]. In those hearts with a subaortic ventricular septal defect, pulmonic stenosis is a common feature. In addition, hearts with a subpulmonic ventricular septal defect may have an associated coarctation of the aorta or mitral valve anomalies. These mitral valve anomalies include mitral stenosis, atresia, or straddling mitral valve [8].