SILENT ASSASSIN: Athletes who succumb to sudden cardiac death during racing or training usually have an undetected, underlying cardiac condition. Picture: THINKSTOCK
SILENT ASSASSIN: Athletes who succumb to sudden cardiac death during racing or training usually have an undetected, underlying cardiac condition. Picture: THINKSTOCK

JUST because you are young, fit and strong doesn’t mean you have a healthy heart. The deaths of two young athletes during the Iron Man 70.3 endurance race in East London in January are a reminder that even a good lifestyle habit such as exercise can put a strain on a weak heart that can be fatal in certain circumstances, says Dr Vash Mungal-Singh, CEO of the Heart and Stroke Foundation South Africa.

The deaths should not make anyone want to stop exercising and head for the couch, she says. Rather, they prove the value of knowing your health status and risks, getting the right screening, exercising appropriately, and making the right lifestyle choices throughout life, for your heart’s sake, says Dr Mungal-Singh.

The athletes, 29-year-old Kevin Staessen of Johannesburg and 37-year-old Berton Bosman of Pretoria, both collapsed during the first leg of the Iron Man 70.3 endurance race in January. Both suffered sudden cardiac death, the medical term for an unexpected, "natural" death after sudden cardiac arrest, a condition in which the heart suddenly and unexpectedly stops beating.

Neither Staessen nor Bosman was known to have a heart problem or any other serious medical condition before participating in the gruelling event. The Iron Man 70.3 triathlon, often called the Half Iron Man, is designed to test the endurance of athletes over a 1.9km swim, 90km cycle race and a half-marathon run. Both were later found to have an underlying heart condition of which they were unaware.

They join a long list of athletes at the top of their game internationally who have dropped dead during races or intensive training that put an extra workload on a vulnerable heart.

Most recently, in May 2012, Norwegian world swimming champion Alexander Dale Oen, 26, suffered cardiac arrest and died after a training session in Flagstaff, Arizona. A few days earlier, Italian footballer Piermario Morosini, 25, collapsed on the field during a match against Italian side Pescara.

And while an sudden cardiac death is usually fatal because of the speed of onset, there have been rare instances of survival. In April 2012, English Premier League footballer Fabrice Muamba, a player described as "renowned for his fitness throughout the game", was just 23 when he collapsed on the field during a match against Tottenham Hotspurs.

Muamba’s heart stopped beating for 78 minutes, and he was pronounced "technically dead" before doctors managed to get his heart going again. He made a full recovery but has since retired from the sport that helped nearly kill him.

The reality, though, is that sudden cardiac death does not affect only fit, young athletes. They are the ones who make the headlines because no one expects fit, strong, young people to drop down dead suddenly, for no apparent reason.

Way back in 1998, University of Cape Town sports scientist Prof Tim Noakes, writing in Sports Science, the Peer-Reviewed Journal and Site for Sport Research, said: "Sudden death in athletes will always be an emotive topic, for it suggests that athleticism may not prevent the development of heart disease, and may actually increase the likelihood that the athlete will die suddenly during exercise."

Prof Noakes went on to say: "Regular exercise reduces the overall risk of sudden death in persons with latent coronary artery disease, yet acutely increases the risk of sudden death during exercise for those with heart disease that predisposes to sudden death."

However, it’s not the activity per se that causes the sudden death. Rather it is the presence of an underlying heart condition, and it requires a trigger to set it off, and not all triggers are exercise-related.

That’s because at heart, sudden cardiac death is most commonly "an electrical problem" — irregularities in the heart’s electrical impulses that cause the heart to beat erratically, known in medical terminology as an arrhythmia, Dr Mungal-Singh says.

Arrhythmias cause a heartbeat that is either too rapid (tachycardia), chaotic (ventricular fibrillation), or too slow a beat (bradycardia). All can cause cardiac arrest and sudden death, she says.

Arrhythmias put extra workload on the heart because they cause the heart’s ventricles to quiver or flutter instead of pumping blood round the body in the naturally well-co-ordinated way, says Dr Mungal-Singh. When the heart’s pumping action is disrupted, blood flow to the body stops, resulting in sudden cardiac arrest.

In most cases, when a person is young, a lethal arrhythmia is caused by an undetected underlying heart condition. It is most commonly congenital or genetic (most of us use the terms interchangeably but there’s a difference, Dr Mungal-Singh says: congenital simply means something you are born with; a genetic abnormality is inherited — in other words, something that runs in your family line).

A variety of noncardiac conditions can also cause a sudden cardiac death, including a pulmonary embolism, in which a clot is released, as well as asthma, epilepsy or an intracranial haemorrhage. Serious infections such as meningitis and encephalitis, or even just flu that can cause a viral-induced sudden cardiac death by putting extra workload on the heart, Dr Mungal-Singh says.

It is important to use heart medications correctly, as misuse of anti-arrhythmics, anti-hypertensives (to treat high blood pressure), antihistamines (for allergies), antidepressants and antibiotics, can lead to sudden cardiac death, though thankfully this is rare, she says.

Prolonged abuse of prescribed drugs has also been found to cause abnormal heart rhythms and sudden death.

And research shows an association with recreational drug use, such as cocaine, she says.

Another factor in sudden cardiac death can also be obesity, which is epidemic in South Africa. Too much adipose tissue — the euphemistic medical term for excess fat — means extra workload for the body and heart, she says, and can put the extra workload on the body that ends up being a trigger for an sudden cardiac death.

There are no definitive statistics on the incidence of sudden cardiac death in South Africa. Estimates range from between one in 50,000 one in to 300,000.

"We think that approximately 2,000 South Africans die annually from sudden cardiac death," says Dr Mungal-Singh.

Sudden cardiac death can be avoided if the condition is properly diagnosed and picked up early enough, she says, and the person receives the right supportive treatment — immediate CPR or a defibrillator.

The problem is that, in most cases of sudden cardiac death, the person is not known to suffer from the problem, so it is not picked up immediately, leading to a waste of precious time. And "you don’t generally have defibrillators all over the place", says Dr Mungal Singh.

"If you have a sudden cardiac event and you are not near a defibrillator, you are at high risk of dying."

An aggravating factor is that in many cases of underlying heart conditions, there are no warning signs at all, although in some cases affected children and young adults may suffer unexplained blackouts when they appear otherwise healthy, or experience muscle weakness and congenital deafness, she says.

That’s all about the problems. What about solutions?

For starters, don’t rest on any laurels, because like most adults these days, you are likely to be at risk, she says.

The majority (80%) of heart conditions are caused by lifestyle choices, says Dr Mungal-Singh, and just about everyone carries a risk factor for cardiovascular disease. This can be from eating badly — food high in fat, sugar or salt — being overweight, smoking, and drinking too much alcohol or not exercising sufficiently.

"These are all risk factors that push you in the direction of a sudden cardiac event," she says.

The real starting point of prevention, Dr Mungal-Singh says, is the same as for every adult, and that is to:

• Be screened;

• Know your cardiac health baseline: your blood pressure and pulse rate, blood glucose and cholesterol levels;

• Know your body mass index: but remember BMI can be misleading — it is possible to have an apparently normal BMI but carry fat in dangerous areas of the body — mostly abdominal fat;

• If there is a family history of sudden cardiac death, you and any relatives should have a medical assessment, scan or genetic testing to detect an underlying, treatable condition as early as possible. Usually children develop this condition after the age of 10, so they should be retested at a later stage, even if they test negative before the age of nine or 10;

• If you are an athlete, are ill or your immune system is down for any reason, give yourself sufficient time to recover; and

• If you are doing endurance exercise, get assessed with basic health screening, including an ECG, and be examined by a doctor before you get involved in high-intensity exercise.

Those are all the basics of ensuring you are monitoring your heart status correctly, says Dr Mungal-Singh. If you are diagnosed with an underlying heart condition, you will also be told which medications to avoid.

It’s all about listening to your body, she says: don’t ignore symptoms or signs, such as pain, an abnormal pulse rate, or the feeling that you’ve run a marathon when you haven’t. And exercise regularly. That doesn’t mean running marathons.

"We know exercise is important for good health and strong hearts," Dr Mungal-Singh says. "The majority of us can undertake moderate levels of activity that can be as basic as walking, or anything that increases your heart rate a little.

"If you have known conditions, consult your doctor before engaging in more intensive exercise."

Heart and Stroke Foundation dietician Erika Ketterer says irrespective of whether you are overweight or obese, if you increase your activity levels, you will protect your heart.

"Compared with those who exercise regularly, inactive people double their risk of suffering a heart attack and dying immediately after such an attack," she says.

"A sedentary lifestyle is also linked to depression, anxiety, osteoporosis, stress and ageing less healthily. Following a healthy lifestyle and being physically active is crucial in the fight against cardiovascular disease."

Dr Mungal-Singh says: "There is still no substitute for the right lifestyle choices as a way to ward off heart conditions."