Background: The incidence of sudden cardiac death in persons under age 40 is roughly 3 per 100 000 persons per year in Germany and North America. Many of these deaths are found to be due to hereditary heart diseases, often a primary structural heart disease associated with arrhythmia or else a primary arrhythmia syndrome in a structurally normal heart. Such diseases are usually of autosomal dominant inheritance, often affect otherwise healthy persons, and can generally be well treated if recognized early. Patients commonly have affected relatives who are still asymptomatic.
Methods: This review is based on articles up to May 2010 that were retrieved by a selective search of the Medline database via PubMed, with additional consideration of the relevant European and American guidelines and the German Law on Genetic Diagnosis.
Results and conclusion: Hereditary arrhythmia syndromes are now found in more than half of all initially unexplained cases of sudden cardiac death in young persons. Among such cases, the hereditary arrhythmia syndrome is primary in 70% and caused by an arrhythmogenic structural heart disease in 30%. In addition to autopsy findings, a thorough family history, relevant medical findings obtained during life (if available), the examination of relatives, and directed molecular testing where appropiate enabled establishing the diagnosis. Arrthymia syndromes that can cause sudden death are often detectable during life if physicians and the public are appropriately sensitized.