Silke Kauferstein of the Department of Forensic Medicine of the Johann Wolfgang Goethe University, Frankfurt, described sudden cardiac death as unexpected death occurring rapidly in persons who had previously seemed to be healthy.

She and her co-authors in the current Deutsches Arzteblatt International have revealed that it is one of the most frequent causes of death in Europe, with about 100 000 people dying due to it in Germany alone each year.

Even though SCD mostly affects older people, 5-15 per cent of cases are in young people who had previously been asymptomatic.

While cardiovascular changes may explain most of the sudden cardiac death cases, no cause of death can be established in 10 to 30 per cent of the cases, even after a post-mortem.

The researchers say that genetically linked diseases of cardiac ion channels are responsible for at least a third of these deaths.

Given that the ion channels are involved in stimulation and conduction in the heart, the researchers say that malfunction can cause cardiac arrythmias, which may lead to ventricular fibrillation.

According to them, these primary electrical heart disorders are mostly subject to autosomal dominant inheritance, which means that family members have a 50 per cent risk of being carriers of the modified gene causing the disorder.