Sudden death in the young.

BACKGROUND: Sudden death is rare in young people, but it has a disproportionate impact on the community.
OBJECTIVES: The purpose of this study was to determine the causes of sudden, natural death in persons aged 5-35 years.
METHODS: All autopsies conducted at a forensic medicine facility in the years 1995-2004 (inclusive) were reviewed. This facility serves more than 2.5 million people in the eastern part of Sydney, Australia. Data collected included subject age, height, weight, gender, circumstances of death, and pathologic findings at autopsy. Deaths caused by trauma, accidental causes, drowning, and drug toxicity were excluded from analysis.
RESULTS: There were 427 nontraumatic, sudden deaths in the 10-year period (70.7% male). Cardiac causes accounted for 56.4%, noncardiac causes 39.3%, and undetermined cause 4.3%. The most common cardiac cause of sudden death was presumed arrhythmia in those with no or minimal structural heart disease (29.0%). Other cardiac causes were acute myocardial infarction (24.5%), myocarditis (11.6%), hypertrophic cardiomyopathy (5.8%), aortic dissection (5.4%), and dilated cardiomyopathy (5.4%). More than two thirds of deaths caused by acute myocardial infarction occurred in the age group from 30-35 years. Sudden cardiac death occurred during physical activity in 10.8% of cases. Sudden cardiac death was reported in a first-degree relative in 4.5% of decedents. The most common noncardiac causes of sudden death were epilepsy (23.8%), intracerebral hemorrhage (23.8%), asthma (16.1%), and pulmonary embolism (12.5%).
CONCLUSION: Presumed cardiac arrhythmia is the most common cause of sudden, natural death in the young. There was no reported history of sudden death among the relatives of most decedents.