Unexpected sudden death of a 12-year-old male with congenital single coronary artery.

A rare autopsy case of a 12-year-old male with a single coronary artery is reported in which he suddenly and unexpectedly died after a brief period of physical and mental excitation. The single coronary artery originated from the left aortic sinus, then branched out the left circumflex artery and afterwards descended as the left anterior descending artery, while the right coronary artery originated almost at a right angle from the left anterior descending artery. The entire heart as well as the cardiac conduction system depended exclusively on the single coronary artery for oxygenated blood supply, and the unbalanced blood distribution on his exertion probably led to sudden cardiac death. Moreover, in this case, both the deceased's mother (at the age of 20 years) and grandmother on the mother's side died suddenly, thus suggesting a possibility of maternal transmission of this congenital anomaly in his family.