Hearts with twisted atrioventricular connections: findings at MR imaging.

The "crisscross" heart and the heart with "superoinferior ventricles" are closely related congenital cardiac malformations that are characterized by twisted atrioventricular connections. The authors studied the morphologic characteristics of three hearts with twisted atrioventricular connections as seen on magnetic resonance (MR) images. The most important clue to the diagnosis was the distorted atrioventricular connections that were demonstrated on serial images. The axes of the atrioventricular connections through the atrioventricular valves were not parallel to each other. The presence of unusual recesses in the cardiac chambers, the angulated or curved configuration of the atrial and ventricular septa, and the unexpected great arterial relationship for the given combination of segmental connections supported the findings of twisted atrioventricular connections. MR imaging facilitated the precise morphologic diagnosis of these hearts.