Sudden Cardiac Death in young adults – red flags and prevention

When sudden cardiac death occurs in the young it is often during physical activity such as playing sport and is more common in males.

What causes these SCDs?

Every week 12 young people die from sudden cardiac death due to undiscovered heart defects or overlooked heart abnormalities. The most common cause of SCD is a heart abnormality. This results in an abnormal heart rhythm, usually ventricular fibrillation (this is when the ventricles of the heart beat in a fast, chaotic fashion). Other causes of SCD include:

• hypertrophic cardiomyopathy (HCM) – this is commonly an inherited condition where the heart muscle walls become thick. The thickened muscle can then affect the heart’s electrical system leading to fast or irregular heartbeats (arrhythmias) which can lead to sudden death. HCM is the most common cause of heart related sudden death in people under 30, particularly in athletes. Unfortunately HCM often goes undetected.
• coronary artery abnormalities – sometimes people are born with coronary arteries that are connected abnormally. These arteries then become compressed during exercise and do not provide proper blood flow to the heart muscle.
• long QT Syndrome – this is an inherited heart rhythm disorder which can cause fast erratic heartbeats, often leading to fainting. Young people with Long QT Syndrome have an increased risk of sudden death.
• undetected congenital heart disease (present at birth) and heart muscle abnormalities.
• inflammation of the heart muscle as a result of a virus or other illness.
• other abnormalities of the heart’s electrical system which can cause sudden death.

A rare cause of sudden cardiac death in anyone can be caused by a blunt blow to the chest, such as being hit by a cricket bat, hard ball or another person. Such a blow to the chest can trigger ventricular fibrillation if the blow strikes at exactly the wrong time in the heart’s electrical cycle. This is known as Commotio Cordis.

What are the red flags that someone is at risk of SCD?

Many times the deaths occur with no warning and cannot be prevented, however the following should be investigated:

• Unexplained fainting (syncope), particularly if it occurs during physical activity;
• A family history of sudden cardiac death before the age of 50;
• Shortness of breath or chest pain can indicate a risk of sudden cardiac death but it can also indicate other health problems in young people such as asthma;

Can sudden death in young people be prevented?

In the UK, if you play professional competitive sport a cardiac screen is mandatory. Should any underlying cardiac condition be found which would put you at risk, you may be advised to stop playing. It is not always the case that routine screening for athletes prevents sudden cardiac death but it can help to identify certain people who are at increased risk.

Fast appropriate medical care increases the chances of survival alongside giving CPR and the use of defibrillator which can improve the chances of survival.