double inlet ventricle

both atrioventricular valves drain to a single ventricular chamber.

both atrioventricular valves drain to a single ventricular chamber of left ventricular morphology. the aorta arises from an anterosuperior rudimentary right ventricle which is not well seen in this example. the aorta arises anterior to the pulmonary artery and is hypoplastic suggestive of an associated coarctation.

description

in this condition, both atrioventricular valves drain predominantly to one ventricle, usually a morphological left ventricle. the great arteries are usually transposed with the aorta arising from an antero-superior outlet chamber, which communicates with the main chamber via a vsd. the neonate will present with congestive cardiac failure or failure to thrive. pulmonary artery banding, to restrict pulmonary blood flow, is usually the first form of treatment with conversion to a fontan circulation at a later stage. obstruction to the ventricular septal defect can occur and restricts the outflow to the aorta. in this setting, the vsd may require enlargement.

diagnosis

the four chamber view will be abnormal as no ventricular septum is seen dividing the ventricular mass equally between the two atrioventricular valves. the flow from both av valves leads into one ventricular chamber which usually has the characteristics of a morphological left ventricle. the great arteries usually arise in parallel orientation with the aorta arising from an outlet chamber, which is usually in an antero-superior position. the vsd varies in size. pulmonary stenosis can also occur. in double inlet right ventricle, both great arteries usually arise side-by-side from a bilateral infundibulum and a small posterior rudimentary left ventricle may be found.

differential diagnosis

in the four chamber view, it is possible to mistake this for a large ventricular septal defect; the differentiation is important as the surgical management and outcome will be quite different. in double inlet ventricle, a ventricular septum can be found separating the main chamber from the outflow chamber but it will not be seen in the four chamber view when both av valve orifices are seen.

sonographic features

both av valves drain to one ventricular chamber.

no ventricular septum seen in the 4 chamber view.

usually abnormally related and positioned great arteries.

associated syndromes

none

references

anderson rh, mccartney fj, shinebourne ea, tynan m (eds) in: paediatric cardiology churchill livingstone: edinburgh, p643-675
allan ld, sharland gk, milburn a, lockhart sm, groves amm, anderson rh, cook ac, fagg nlk prospective diagnosis of 1,006 consecutive cases of congenital heart disease in the fetus j am coll cardiol 23:1452-8
allan ld, sharland g, cook a in: color atlas of fetal cardiology mosby-wolfe: london, p59-69
elliot lp, anderson rh, bargeron lm, kirklin jm, white rd in: heart disease in infants, children and adolescents adams fh, emmanouilides gc, riemenschneider ta (eds) williams and wilkins: baltimore, p485-504