conditions is often the cause of sudden cardiac death
The causes of sudden cardiac death in young people vary. Most often, death is due to a heart abnormality. For a variety of reasons, something causes the heart to beat out of control. This abnormal heart rhythm is known as ventricular fibrillation. Some specific causes of sudden cardiac death in young people include: 1  Hypertrophic cardiomyopathy (HCM). In this usually inherited condition, the walls of the heart muscle thicken. 2  Coronary artery abnormalities. Sometimes people are born with heart arteries (coronary arteries) that are connected abnormally. 3  Long QT syndrome.