Incidence
Due to its rarity, the true incidence with either usual or mirror-imaged
atrial arrangement, or in association with isomerism of the atrial
appendages, is difficult to establish. The incidence in patients with
congenital heart diseases was reported as 0.2% in necropsy
studies,7,18,23,37-42,63-66 0.5%-0.98% in
echocardiographic series,11,21 and 1.7% when using
computed tomography.4,19,41,71 Its occurrence without
any associated cardiac or aortic arch anomaly is extremely rare. Its
prevalence is estimated at 0.02%.14-17,33