The sudden death of an athlete always causes distress and concern – these people are normally at the peak of their careers, and exercise is meant to be good for you, so why does it happen?
Sudden Cardiac Death (SDC) has been known of since 490BC when the Greek soldier Pheldippides died after completing the historic run from Marathon to Athens to deliver the message of victory over the Persians.
A number of congenital cardiovascular diseases have been linked to sudden death in young trained athletes. The main cause is Hypertrophic cardiomyopathy (HCM) – a thickening of the heart wall. Congenital coronary anomalies, mostly due to a wrong origin of the left main coronary artery, are the second leading cause of sudden athlete death.
Commotio Cordis or Innocent Chest Blow is the leading non-congenital cause of SCD – A relatively modest and non-penetrating blow to the chest can be produced by an object like a ball or puck or by bodily collision with another athlete. Not uniformly fatal, 10% of the victims are known to have survived, usually with prompt CPR and defibrillation.
The disease responsible for causing death also depends on the age of the athlete. Younger athletes are more likely to die from congenital disorders of the heart, while older athletes usually have evidence of coronary artery disease. The overall athlete population is generally at low risk.
Estimates in US range from 1:160,000 to 1:300,000 competitive athlete deaths a year due to cardiovascular disease. In Italy, the Veneto region utilized a regional registry for juvenile sudden death and reported an incidence of 1:28,000 for young competitive athletes (12-35yo) due to Sudden Cardiac Death. A population based study in 11 US and Canadian cities found 1:27,000 (14-24yo) incidences of Sudden Cardiac Death.
A study conducted by the British Journal of Sports Medicine states that estimates vary 10 fold due to lack of mandatory reporting, however SCD remains the leading cause of death in young athletes. Incidences may be under-reported as mostly elite or high profile athletes identified. In contrast, deaths of non-elite athletes in many circumstances are probably less likely to achieve public recognition in the mainstream press and are more likely to escape reporting. Males are more likely to be affected than females – in a study of 158 SCD cases only 15% were female.
Preparticipation screening consisting of a personal and family history questionnaire and physical examination without any noninvasive testing, such as an echocardiogram, is not enough to detect cardiac abnormalities that may lead to a higher risk of SCD. A partially obstructed aortic valve is likely to be detected during a routine physical examination. However, hypertrophic cardiomyopathy (HCM), which accounts for the majority of sudden deaths in young athletes, may not be identified at all.
Generally, the addition of noninvasive diagnostic tests to the screening process has the potential to enhance the detection of certain cardiovascular defects in young athletes. For example, an echocardiogram is the tool for clinical recognition of HCM and many other cardiovascular diseases responsible for sudden death in young athletes. In cases of diagnosis of abnormal coronary artery or genetic defects of the heart, a coronary angiogram or magnetic resonance imaging (MRI) would be required.
These tests are cost prohibitive for the majority of athletes, teams and health care systems. For example, the cost of one comprehensive echocardiographic evaluation averages approximately around $600-$700, depending on the geographical cost of care. Assuming that HCM occurs in 1 out of 500 athletes, then the cost to diagnose one athlete with HCM would range from $250,000 to $400,000.
The standard 12-lead ECG has been suggested as a more practical and cost-efficient alternative to population-based echocardiography. However, when used as a primary-screening test, the ECG is not as accurate as the echocardiogram because it does not have the imaging capability. It is also possible to have HCM or another cardiac disease seen on echocardiography but have a normal ECG, and vice versa, it is possible to have an abnormal ECG and a normal echocardiogram.
In Italy high level athletes are required to complete a history and physical examination, 12-lead ECG, exercise and pulmonary function tests and echocardiography, as recommended by the IOC in the Lausanne Recommendations as well as the European Society of Cardiology. The physician clearing the athlete to participate in a competitive sport bears responsibility for the diagnosis and becomes liable in an event of sudden death due to incorrect or incomplete diagnosis.
In the US and Canada there is no approved certification procedures for medical professionals that perform screens and no universal screening procedure.
There are a number of other causes of sudden death in athletes that are not related to cardiovascular disease, such as exercise-induced asthma and respiratory arrest, exercise-induced anaphylaxis, malignant hyperthermia, heat stroke and drug abuse.
Gavin Leung, Coordinator, Sport Safety for SportMedBC says “it is always tragic when a person dies at such a young age. Especially one who should be at the pinnacle of health. Hopefully Bernd’s death will raise awareness for Sudden Cardiac Death so that we can help prevent more of our young athletes from dying before their time”.
A memorial service for Bernd Dittrich was held at SFU’s West Gym on Monday November 23rd.