Above 35 years of age, the most common cause of sudden cardiac death is coronary artery disease (blockage of the blood vessels that supply the heart with oxygen).
 

Under 35 years of age, the most common cause of sudden cardiac death is “undetermined” or “unascertained” i.e. after a comprehensive postmortem (also called an autopsy), the pathologist was unable to work out why the person died.
 

A study from Australia and New Zealand examined the cause of death in young people aged 35 years and under. Forty percent (40%) of young people who pass away suddenly have no cause of death identified postmortem this is often called an “undetermined” or “unascertained” cause of death.
 

One possibility of an undetermined cause of death can be a rhythm problem of the heart, causing cardiac arrest. Some rhythm problems are genetic.
 

In other cases, a cause of death is identified at postmortem. These are often problems with the structure of the heart. Some of these structural problems are genetic.
 

When there is a possibility of a genetic cause of death (rhythm or structural problem of the heart), it is recommended immediate family members visit a heart specialist (cardiologist) for clinical screening (heart checks).