Heart Attacks, Sudden Deaths and Athletes

In 2012, fans of English football watched in horror as 23-year-old Bolton Wanderers midfielder Fabrice Muamba suddenly collapsed with a heart attack during a televised away match against London's Tottenham Hotspur. Luckily, he owes his life to the speed of treatment of Tottenham's medical staff on duty, and, not least, to one of the fans: a consultant cardiologist who helped to rush him to hospital. Although Muamba's heart had stopped for 78 minutes, he survived – although he no longer plays professional football.

Dr Paul Chiam, a cardiologist at Mount Elizabeth Hospital, answers questions about what causes heart attacks in young people – and what you can do to avoid them.

Heart attacks in young people

What is the main cause of death (or heart failure) in young healthy athletes?

The likeliest cause is sudden cardiac arrest. This is most commonly due to ventricular fibrillation (an abnormal, irregular heartbeat). The top two causes of irregular heartbeat in young athletes:

• Hypertrophic cardiomyopathy (heart muscle thickening)
• Inborn electrical conduction abnormalities (that affect the normal rhythm) of the heart.

Is there a gender bias?

Yes. The majority of a sudden cardiac arrest occurs in males.

How rare is this?

It's not rare – but not that common either; 1,000 Singaporeans suffer sudden cardiac arrest per year, and half of them are below 60 years of age.

Heart attacks and exercise

Are athletes in particular sports (maybe contact sports) at greater risk or is the problem caused simply by excessive exercise?

There is no evidence that contact sports bring a higher risk. The risk is likely due to the exercise itself.

Does this mean there are dangers in training too hard? Could exercise cause heart attacks?

In a patient with hypertrophic cardiomyopathy (heart muscle thickening), severe physical exertion can trigger a cardiac arrest. However, for the vast majority of people, without an existing heart condition, there is no evidence that severe physical exertion will trigger a cardiac arrest.

Does this affect just elite athletes or can it be dangerous for amateur fitness fanatics who spend too long in the gym?

A cardiac arrest can happen to anyone if they have an underlying heart muscle disorder or underlying electrical rhythm disorder.

What is your advice for fitness fanatics – what should they be monitoring?

Start slowly and exercise according to your tolerance. Build up the intensity and duration of exercise gradually. I recommend seeking a professional assessment of your fitness before extreme sporting events.

Should I go for a heart check-up before taking up a vigorous sport?

For those who have a family history of heart disease or sudden cardiac arrest, or if they have a history of fainting during exercise, a baseline resting electrocardiogram (ECG)would be a simple screening tool. In some people, a heart ultrasound (echocardiogram) may be needed. If in doubt, consult and discuss the exercise plan with a physician.