Hypoplastic coronary artery disease within the spectrum of sudden unexpected death in young and middle age adults.

The etiology of sudden unexpected death in young and middle age adults is frequently listed as undetermined, thereby causing much grief and fear among family members. When careful, methodical autopsies were performed, a significant number of cases of hypoplastic coronary artery disease (HCAD) were found where no other etiological factor could account for the deaths or where there was a solo coronary occlusion proximal to the hypoplastic coronary artery. This is in marked contrast to the small number of cases that have been reported, indicating that HCAD is more common than is generally realized. A representative series of seven cases of sudden death due to HCAD is presented, possible mechanisms of death in HCAD are fully discussed, and recommendations for an autopsy checklist for investigating sudden cardiac death at autopsy are presented.