Abstract
We present a prenatally diagnosed case of heterotaxy syndrome (HS) in which left atrial
isomerism (LAI) was associated with an aneurysmal enlargement of the right atrial
appendage (RAA). Although LAI is usually associated with complex cardiac and extracardiac
anomalies, the association of LAI and right atrial appendage aneurysm (RAAA) is exceptional.
Congenital RAAA itself is an idiopathic, very rare cardiac anomaly characterized by
the enlargement of the appendage in the absence of any other cardiac or extra-cardiac
defect. The prognosis of the heterotaxy is poor with associated major cardiac malformations
and even cases with minor cardiac anomalies are at risk postnatally for complications
like biliary atresia, intestinal rotational abnormalities, and immune disorders. In
this case, the prenatal diagnosis of the isomerism was mainly based on the abnormalities
of caval veins. Although no typical complex cardiac anomaly was present, the HS was
associated with biliary atresia, polysplenia, and malrotation of the gut. Associated
RAAA further imposed an additional risk of complications such as tachyarrhythmias,
thromboembolic events, and aneurysmal rupture.
Keywords
Aneurysm - atrial appendage - heterotaxy - isomerism - polysplenia
