[Myocardial disease mortality in children and young adults. A population-based observational study]

Few studies have investigated death due to myocardial disease in children and young adults. The aim of this study was to analyze the epidemiological, clinical, and pathologic characteristics of death in these cases.

Population-based observational study of all deaths in individuals aged 1-35 years in the Spanish province of Biscay over a period of 12 years.

Forty deaths from myocardial disease occurred in 29 males and 11 females (mean age 25.3 years): 30 sudden and 10 non-sudden deaths. The mortality rate was 0.64 per 100,000 persons-year. The relative risk of sudden death was significantly greater than that of non-sudden death, particularly in adolescents and young males. The cause of death was myocarditis in 12 cases (83.3% sudden death), dilated cardiomyopathy in 10 (80% non-sudden death), arrhythmogenic cardiomyopathy in seven, hypertrophic cardiomyopathy in six, and idiopathic concentric left ventricular hypertrophy in five (100% sudden death). Myocardial disease was diagnosed before sudden death in only three cases. Ten subjects had symptoms and electrocardiogram abnormalities but their cardiomyopathy had not been diagnosed. Six individuals had a comorbid condition (morbid obesity in four), six had prodromal symptoms, and 11 had arrhythmic triggering factors (sporting activity in seven). Ventricular fibrillation was frequently observed during cardiopulmonary resuscitation.

Mortality due to myocardial disease in children and young adults is uncommon. Most deaths are sudden. However, some may be preventable. Preventative measures should be aimed at sudden death in adolescents and young males. There was a noticeable association between arrhythmogenic cardiomyopathy and sporting activity.