Is Sudden Cardiac Death Same as a Heart Attack?

An estimated 1,000 Singaporeans die from sudden cardiac death (SCD) every year, about half of whom are below the age of 60

The most common cause of sudden cardiac death (SCD)

Sudden Cardiac Death: Not as Random as It Looks

A sudden cardiac death is not a heart attack.

An estimated 1,000 Singaporeans die from sudden cardiac death (SCD) every year, about half of whom are below the age of 60

But is sudden cardiac death the same as a heart attack?

"A sudden cardiac death, or SCD, is not a heart attack," said Clinical Associate Professor Aaron Wong, Head and Senior Consultant from the Department of Cardiology at National Heart Centre Singapore (NHCS), a member of the SingHealth group.

"A SCD can be due to many causes but is usually caused by an abnormal heart rhythm due to an abnormal 'electrical circuit' of the heart. A heart attack is caused by blockages in the heart arteries supplying blood to the heart, causing a portion of the heart muscle to be damaged. A heart attack may lead to abnormal heart rhythm, and therefore SCD, but not always."

Unlike a heart attack, which has symptoms such as chest pain and breathlessness, SCD usually has no warning signs. The only way to treat a SCD is to set the rapid heartbeat back to its normal pace by delivering an electrical shock to the heart using a device called a defibrillator.

Patients at high risk of SCD may be advised by their doctors to have an Implantable Cardiac Defibrillator (ICD) implanted. The ICD is a pocket-sized device which detects abnormal heart beats or rhythm and sends an electric current to the heart. This electric current shocks the heart and helps to reset the heart rhythm like a mini-defibrillator.

The most common cause of sudden cardiac death (SCD)

The most common cause of SCD is a sudden onset of abnormal heart rhythm. This is usually due to a fast but chaotic heart rhythm called ventricular fibrillation (VF) or tachycardia (VT). An extremely slow heart rate may cause SCD as well but usually presents with prior symptoms of giddiness or fainting episodes.

In a patient with VF (a form of cardiac arrest), the heart beats 400 to 500 beats per minute and the normal rhythmic contractions of the lower chambers of the heart stop. When this happens, blood and oxygen are not pumped to the rest of the body and within seconds, the brain becomes starved of oxygen and the person loses consciousness. Without immediate treatment, the brain will cease to function and the person can die within minutes.

Ref: N18

Check out other articles on the heart:

Why You Shouldn't Ignore Chest Pains

When are Fast Heart Beats a Concern?

How to Survive a Heart Attack When Alone

How Often Should You Eat Fast Food?

Tips for a Healthy Heart

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