Coronary venous aneurysms and accessory atrioventricular connections.

Histological investigation of a heart with aneurysmal malformation of the anterior cardiac vein showed atypical accessory atrioventricular pathways that could have been the basis for bypass tracts and ventricular pre-excitation. Review of other cases with coronary sinus or venous aneurysms showed a striking association with sudden death. Such malformations may not be as benign as previously thought.