Isolated atrioventricular discordance: surgical experience.

BACKGROUND: Isolated ventricular inversion (atrioventricular discordance with ventriculoarterial concordance) is an extremely rare presentation of cyanotic congenital heart disease. The mode of presentation is akin to D-transposition of great arteries as systemic venous drainage and systemic arterial output connect to the same side of the cardiac septae, and pulmonary venous drainage and pulmonary arterial outflow to the opposite. Systemic oxygenation relies on intracardiac or extracardiac modes of mixing, as does survival, similar to transposition of the great arteries. Published literature is scant, mainly because of the rarity of this cardiac anomaly. We review our surgical experience with this lesion.

METHODS: Five children with isolated ventricular inversion presented to us between the ages of 6 days and 22 months (mean, 12 months). Preoperative echocardiogram diagnosed large interventricular communication in 4, a patent ductus arteriosus in 4, and total anomalous pulmonary venous drainage with supracardiac connection in 1. One had associated narrowing of the left pulmonary artery origin. Four patients had atrial situs solitus, whereas 1 had right atrial isomerism. Three hearts had normally related great arteries whereas in 2, the aorta was to the right and anterior to the main pulmonary artery and arising in parallel fashion from the cardiac mass. Four children underwent trans-right atrial patch closure of the interventricular communications, with ligation of the patent ductus arteriosus. All 4 underwent a concomitant modified Senning's repair. The fifth patient underwent repair of total anomalous pulmonary venous drainage with a Mustard-type repair. One needed concomitant repair of the mitral valve for injury to a free edge chorda sustained during closure of the ventricular defect.

RESULTS: There was 1 early death. Complete heart block developed in 2 children, of which 1 needed permanent pacemaker insertion, whereas the other converted to sinus rhythm with intermittent atrial tachycardia. All survivors are doing well on follow-up, at a follow-up duration ranging from 6 to 48 months (mean, 18).

CONCLUSIONS: Repair of isolated atrioventricular discordance can be successfully achieved in the majority of patients presenting with this complex anomaly.