Sudden unexpected death in children with heart disease.

Objective: To review a mortality database, and identify all sudden unexpected deaths in patients followed by the cardiac program.
Design: Retrospective review of prospectively maintained database.
Results: Over 8 years, we identified 80 sudden unexpected deaths, among which there were sufficient data in 69 (24 females). Patients died at a median age of 17.2 months (28 days-18.8 years). Forty-six patients had 2 functional ventricles and 23 had received palliation for a single-functional ventricle. Patients with a single ventricle died at a younger age (median 120 days; 28 days-17.2 years) and sooner after last assessment (median 27 days; 1-146 days) than patients in the biventricular group (median age 2 years; 43 days-18.8 years; median time since last assessment 49 days, 1 days-1 year) (P < .01; P = .01). Thrombosis was the most common cause (61%) of death in the single-ventricle group. Arrhythmia or presumed arrhythmia was the most common cause (46%) of death in the biventricular group. Fifty-one patients had undergone surgery. Six patients had primary electrophysiological disease, and 5 had cardiomyopathy. Eight deaths occurred in patients with pulmonary vascular disease.
Conclusion: Our study demonstrates that sudden unexpected death occurred at a frequency of at least 10 patients per year over an 8-year period with 55,730 patient encounters. We were able to determine a clinical cause of death in most patients. Arrhythmias (30%) and pulmonary vascular disease (13%) are important causes of sudden death. Simple aortic valve disease and hypertrophic cardiomyopathy are rare (4%) causes of sudden death in childhood. Infants and young children with surgical shunts comprise 23% of sudden unexpected deaths that occur within a month of the last evaluation. Close surveillance of these patients is warranted.