upstairs downstairs heart

Criss-cross heart or upstairs downstairs heart.

Criss-cross heart or ‘upstairs–downstairs’ heart.
Review by S.Gerboni

Lev and Rowlatt in 1961 described unusual arrangement of the cardiac inlets :
ventricular chambers arranged in a superoinferior fashion,
with the RV superiorly and the LV inferiorly located.
The term Criss-cross heart,was introduced by Anderson et al. in
1974, defined as crossing of the long axes of the AV valves.