Successful atrioventricular nodal reentrant tachycardia ablation in a 2-year-old girl with discordant crisscross heart

Criss-cross heart is an extremely rare congenital heart defect defined as the crossing of the long axis of the atrioventricular (AV) valve. It was first described by Lev and Rowlatt in 1961,1 and the term “criss-cross heart” was initially coined by Anderson et al in 1972.2 According to the AV connection, criss-cross heart can be categorized into two types: concordant and discordant. In the concordant type, the inflowing blood streams from the right atrium (RA) to the right ventricle (RV) and from the left atrium (LA) to the left ventricle (LV) intersect.