Sudden cardiac death in athletes: the paradox

This morning, I woke to hear of yet another tragic death of a high level, elite athlete. Piermario Morosini, a 25 year old Italian football player, died during a game. An apparently well, healthy and fit young man, who represented Italy as an under-21 year old, is now dead. Why?

At this point the cause of Morosini’s death has not been revealed, but statistically, the most likely cause is an underlying genetic heart disease. These diseases are caused by a fault (DNA mutation) in one of the 23,000 genes we are born with, which can then lead to a variety of heart diseases that can affect the structure, function, and electrical rhythm of the heart. The most common cause of sudden death is hypertrophic cardiomyopathy (HCM), which affects up to 1 in 500 people. Tragically, these genetic heart diseases are often silent. The individuals have no symptoms. And even more sadly, sudden death can be the first presenting symptom in up to 50% of young people who die suddenly.

So how can a person who carries a gene fault which can lead to these heart diseases, get to such an elite level of sports before any symptoms arise? This is the paradox, i.e. athletes who represent the peak of physical and sporting excellence, can also be carrying genetic faults that for no apparent reason suddenly cause a fatal rhythm disturbance leading to cardiac arrest and sudden death. Some are very lucky and survive, such as Bolton player Fabrice Muamba, who collapsed a few weeks ago during an FA Cup quarter final, required 17 defibrillator shocks, and miraculously survived. However, the vast majority, like Morosini, are unable to be resuscitated. Some have argued that diseases such as HCM, a disease which results in the thickening of the heart muscle, may initially give athletes a “super heart” leading to sporting excellence, but ultimately can trigger arrhythmias leading to sudden death. Others have postulated that high-level exercise may remodel the heart that can lead to rhythm problems. The paradox however remains. Elite sports people can achieve the highest levels of sporting excellence, yet be at risk of sudden cardiac death.

So how can we prevent sudden cardiac death, particularly in the young, in our community? In my opinion, sudden cardiac death in the young is a complex problem and so the solution must address the problem from a number of perspectives. These include a number of practical approaches:

  1. Raising community awareness that young people can develop life threatening heart diseases, which can lead to sudden death.
  2.  In families where there is a history of young sudden death, or heart disease at a young age, clinical screening of all relatives should be undertaken.
  3. If young people have symptoms such as blackouts (syncope), fast heart rhythms, and exercise-related symptoms, they should have a medical review.
  4. Greater use of public access defibrillators, which have been shown to improve the chances of survival from a cardiac arrest in the community, e.g. in airports, train stations, sporting clubs, major sporting venues.
  5. Population-based screening: this remains a much-debated issue. For example, in Italy, a national ECG screening program exists for all high school students. Most countries do not have such national programs but have screening programs within particular sports programs, sporting clubs, and sports institutes. The debate hinges around many factors including the low incidence of these genetic heart diseases, the high rate of “false positives” on ECG changes which may preclude some kids unnecessarily from sports, the cost-effectiveness of finding rare diseases, and whether you can actually diagnose some of the diseases. For example, the diagnosis of hypertrophic cardiomyopathy, the most common cause of sudden death in the young, including athletes, is made on echocardiography (ultrasound) and not an ECG.

The key point is that if we can identify those young people at risk of developing sudden death, we can initiate prevention strategies today to stop sudden death, such as lifestyle modifications, medical therapies such as beta-blockers, and implantable cardioverter-defibrillator (ICD) therapy. Targeted research focused on the problem of sudden death in the young, including genetic, clinical, public health, and health economic aspects, will be critical as we aim to prevent all sudden cardiac deaths amongst the young in our community.

Chris