Previous Page
SPORTS MEDICINE SUDDEN CARDIAC DEATH
about its effectiveness and the level of evaluation that should be undertaken. In the USA, pre-participation
screening has involved personal and family history and physical examination. Any other testing is at the discretion of the examining professional (7). One retrospective analysis of 134 athletes who died suddenly showed that only 3% were suspected of any cardiovascular abnormality using standard history and physical examination (6). Screening programmes in the UK suggest that a vast majority (> 80%) of athletes identified with potentially serious cardiac disorders are completely asymptomatic (5).
Many of the screening statistics come from Italy where systematic pre- participation screening programmes have been in place for more than 25 years. It is based on history, physical examination and additionally, a 12- lead ECG. A 12-lead ECG is a simple, non-invasive and painless test that examines the electrical activity of the heart. It simply involves the patient lying down for approximately 5 minutes whilst 10 small stickers (electrodes) are placed on their chest and limbs. Flexible leads then extend from the ECG machine and are attached to the electrodes, which record the hearts’ electrical rhythm on thermal paper. It has been shown that ECGs are
interpreted as abnormal in up to 95% of people with (HCM) (10), as well as helping with the identification of a number of other conditions, therefore ECG has the potential to
greatly increase the sensitivity of the screening process. A study over a 17 year period by Corrado et al (11) evaluated the results of 33,735 athletes screened
CONDITION
Hypertrophic Cardiomyopathy (HCM)
Arrhythmogenic right ventricular cardiomyopathy (ARVC)
Congenital anomalous coronary arteries
Wolff-Parkinson-White syndrome
Long QT and Brugada syndrome Myocarditis
Marfan’s syndrome FEATURE
Thickening of the ventricle(s) in the absence of cardiac or systemic cause
Patchy fibro fatty replacement of right ventricular myocardium
Abnormal origin of the coronary arteries
Additional electrical connection between the atria and ventricle
Disorders of the sodium, potassium and calcium channels Inflammation of the heart muscle
Connective tissue disorder that affects many organ systems
Table 1: conditions that can be attributed to SCD
between 1979 – 1996. Of these, 1058 were subsequently disqualified from competing in sporting competition, with 621 (1.8%) the result of a clinically relevant cardiovascular condition. An interesting finding was that HCM only accounted for 3.6%.
HCM has been reported as the leading cause of SCD in the USA. Ideally echocardiography is used to identify HCM, however this is expensive and time consuming because of the nature of the scan, and therefore impractical when screening large numbers. 12- lead ECG has been proposed as an alternative cost effective method when screening large numbers. The Italian findings support the use of ECG testing successfully identifying HCM in the general population of young competitive athletes (7).
In total, 22 athletes in Italy were
discovered to have HCM, with only 5 (23%) having a positive family history, a cardiac murmur or both at pre- participation evaluation. These results demonstrate that 12-lead ECG screening utilised by the Italians had a 77% greater power for detecting HCM and therefore is expected to correspond in fewer deaths. In a subsequent 8 year follow- up all athletes identified were all still alive and well (7).
When comparing the finding of the entire Italian population for incidents of SCD, 49 (18%) out of 269 were competitive athletes (44 male, 5
female). Of these, HCM was responsible for only 2% of the athletes screened whereas it was responsible for 7.3% of the general population (7).
12-lead ECG also offers the
possibility to detect (or to raise clinical suspicion of) other conditions with the potential to cause SCD. In addition to the ECG changes seen in HCM, certain characteristic changes can be seen in individuals with possible arrhythmogenic right ventricular cardiomyopathy, Dilated Cardiomyopathy, long QT, Brugada, Lenegre disease, short QT, Wollf- Parkinson White syndrome, premature coronary atherosclerosis and congenital coronary anomalies (7). It is important to note that the identification of the final two conditions can be limited. However it has been reported that approximately a quarter of young athletes who died from these conditions demonstrated symptoms and/or ECG changes indicative of cardiac disease (11). In addition its important to note a number of these conditions have only been discovered relatively recently and the number of individuals being diagnosed is increasing over time (7).
CARDIAC RISK IN THE YOUNG (CRY) AND PHILIPS© ATHLETE SCREENING PROGRAMME CRY has established a screening programme run at the CRY Centre for Sports Cardiology (CRY CSC) based
PEOPLE WITH HCM AND GREATLY INCREASES SCREENING SUCCESS
ECGs ARE INTERPRETED AS ABNORMAL IN UP TO 95% OF
7