Diagnostic yield in sudden unexplained death and aborted cardiac arrest in the young: the experience of a tertiary referral center in The Netherlands

Background: In sudden unexplained death (SUD) in the young (age 1-50 years), cardiologic and genetic examination in surviving relatives may unmask the cause of death in a significant proportion. The causes of aborted cardiac arrest (ACA) in this age group likely are similar to those in sudden cardiac death. However, there is a paucity of recent data on this topic.

Objective: The purpose of this study was to gain insight into the yield of current diagnostic strategies used in relatives of SUD victims and in ACA victims aged 1-50 years in our dedicated tertiary referral center.

Methods: We studied (1) all consecutive families who presented to the cardiology department for examination because of ≥1 first-degree related SUD victim aged 1-50 years and (2) all consecutive ACA victims aged 1-50 years who presented to the cardiology department from 1996 to 2009. Comprehensive cardiologic and genetic examination was performed in both populations.

Results: A certain or probable diagnosis was made in 47 (33%) of 140 SUD families, including 45 (96%) cases of inherited cardiac diseases. Long QT syndrome (19%) was the most prevalent diagnosis. In 42 (61%) of 69 ACA victims, the cause of the event was determined (inherited in 31 [74%]). Hypertrophic cardiomyopathy was most prevalent (17%).

Conclusion: The yield of the current diagnostic workup in relatives of young SUD victims is 33% and is almost twice as high in young ACA victims. Inherited cardiac diseases are predominantly causative in both groups.