Understanding and preventing sudden cardiac arrest

Reports of athletes collapsing with a heart attack midway during a workout or while playing sports are frightening and confusing. The reality is the chances of them occurring are small, unless one already has underlying risk factors.

Heart attacks leading to heart failure or death, also known as sudden cardiac arrest, are most commonly caused by ventricular fibrillation (VF), says Dr Paul Chiam, a consultant cardiologist at Mount Elizabeth Hospital. VF is a disorder in which there is uncoordinated contraction of the ventricles in the heart, making them quiver rather than contract properly.

Causes of ventricular fibrillation (VF)

There are two main causes of VF in young athletes. The first is hypertrophic cardiomyopathy (HCM), where the heart muscle cells enlarge and cause the ventricles to thicken. The condition is usually inherited and caused by a mutation in some of the genes in heart muscle proteins, although high blood pressure, ageing, diabetes and thyroid disease can also cause HCM.

The second cause is inborn electrical conduction abnormalities that affect the normal rhythm of the heart.

“Sudden cardiac arrest is not rare but not that common either,” says Dr Chiam. “A thousand Singaporeans suffer from the condition per year, and half of them are below 60 years of age.”

He adds that a majority of sudden cardiac arrest cases are male.

Heart check-ups recommended for at-risk athletes

A heart check-up is strongly recommended for those with a family history of heart disease or sudden cardiac arrest, or if they have previously experienced fainting during exercise. Abnormalities in the heart may be detected only through tests and for most people a baseline-resting electrocardiogram (ECG) would be sufficient. In some cases, however, an echocardiogram (heart ultrasound) may also be required.

Dr Chiam also advises young people who want to embark on a fitness regime to start slowly and exercise according to their tolerance. This allows them to build up the intensity and duration of exercise gradually. “I recommend seeking a professional assessment of your fitness before extreme sporting events.”

“Patients can also consult and discuss their proposed exercise plan with a physician to ensure that they are suited for the workout,” he says.

Dr. Paul Chiam is a cardiologist at Mount Elizabeth Hospital and an adjunct associate professor at the National University of Singapore. He has hands-on experience in coronary angioplasty, carotid artery angioplasty and stenting, peripheral artery angioplasty and structural heart disease (heart valve) interventions.

The Heart and Vascular Centre
3 Mount Elizabeth #08-06
Mount Elizabeth Medical Centre, Singapore 228510
Tel: +65 6375 3022

The Heart & Vascular Centre (Novena)
38 Irrawaddy Road #09-21
Mount Elizabeth Novena Specialist Centre, Singapore 329563
Tel: +65 6694 0140
www.heartvascularcentre.com