Characteristics of Sudden Death in Inherited Heart Disease

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.