The course of the conduction system in dextrocardia.

This is a serial section examination of the conduction system of five hearts of various types of dextrocardia. In one case of dextroversion the conduction system was found to be normal. In one case of mirror-image dextrocardia the conduction system was normal but in the opposite spatial position. In one heart of mixed (discordant) dextrocardia, the sinoatrial node was in correct morphologic position. There were two atrioventricular nodes - a posterior node close to the coronary sinus and an anterior node in the roof of the morphologic right atrium. They formed two separate bundles which joined in the left ventricle to form a "sling". In two cases of presumptive mirror-image dextrocardia, with a common atrium in situs inversus according to the morphology of the atrial appendages, with common atrioventricular orifice (CAVO), the sinoatrial node was situated in wrong positions. Two atrioventricular nodes and bundles again formed a sling. There are various types of slings in discordant dextrocardia.