Introduction and objectives: Cardiomyopathy and channelopathy are major causes of sudden death (SD). The little information available on the context in which SD occurs has come from only a few referral centers. The objective was to investigate the circumstances surrounding SD in families with inherited heart disease.
Methods: The study included 152 SD patients (mean age 43+/-19 years) from 103 families. The reasons for inclusion were resuscitated SD in 7%, recent SD in 8%, and a diagnosis of cardiomyopathy or channelopathy in a living relative in 72%. Also, 13% were athletes. Family trees were constructed and each death's circumstances were recorded. Autopsy and medical records were reviewed.
Results: Overall, 18% of SDs occurred during physical exercise, 32% during normal daily activities, and 37% during rest or sleep. There was a significant association between male sex and SD: 111 males (73%) vs. 41 females (27%; P=.03). Exercise-related SD was associated with young age (P=.01). The percentage of SDs associated with exercise, stress or normal daily activities was significantly greater with cardiomyopathy than channelopathy (61% vs. 41%; P=.057). All athletes were male and the majority died during exercise (50% vs. 11% of non-athletes; P=.0002). Patients with Brugada syndrome had the highest percentage of SDs during rest or sleep (i.e. 47%). No clear trigger could be identified in 33%.
Conclusions: SD was common in inherited heart disease, which accounted for a significant number of cases. Males clearly predominated over females (ratio 3:1) among SD cases (irrespective of pathological type). Most SDs occurred during exercise or normal daily activities in cardiomyopathies and during rest or sleep in channelopathies. The percentage of exercise-related SDs (i.e. 18%) was higher than expected.