Sudden unexplained death among persons 1-35 years old.

Sudden unexplained death (SUD) on children and young people is unusual, although the real magnitude is unknown. The clinical and physiopathological characteristics are poorly defined. The aim of this work is to analyse the epidemiological, clinical and pathological characteristics of SUD on children and young people. In this population observational study, all sudden non-violent deaths between 1 and 35 years occurred in Bizkaia (north Spain) from 1991 to 1998 were investigated, analysing those diagnosed as SUD. Pathological records, circumstances of death and autopsy findings were obtained. Out of 107 cases of sudden death (SD), 19 were SUD. The mortality rate of SUD was 0.43/100,000 persons per year. Five had pathological antecedents: syncopal episodes in three cases and tachycardia and ventricular extrasystoles one each. The initial symptom was sudden collapse (N=13). In four cases, a precipitating factor was identified (two physical exercise and two emotional stress). Six cases died during sleep. Minimal pathological findings in coronary arteries, myocardium or conduction system was found in nine cases. Heart weight increased (under interval of confidence of 95%) was present in 12 cases. In conclusion, the SUD is very infrequent in children and young people. However, it has great clinical significance because it affects people in good health and occurs without warning symptoms. Some of these cases can be due to cardiac arrhythmias. In deaths in bed there is a high frequency of SUD. In the future, it may be possible that abnormalities at a molecular level will be detected in some of the cases identified today as SUD.