Sudden death caused by stricture of the sinus node artery.

The sudden unexpected deaths of two young people and the findings in their hearts at autopsy are described. The striking feature was marked narrowing of the sinus node arteries by fibromuscular dysplasia. There were no other histological abnormalities present elsewhere. The observations suggest that pathological changes of the sinus node arteries might lead to a terminal cardiac arrhythmia acting as the mechanism of death.