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In 1958, British pathologist Donald Teare described a family in which eight victims of sudden death had marked asymmetric hypertrophy of the left ventricle,1 a condition now known as hypertrophic cardiomyopathy (HCM). Though much has been learnt about HCM, a number of problems remain unresolved, including how best to prevent HCM-related sudden cardiac death (SCD) in young athletes. As recently as the 2008 British Cardiovascular Society meeting, experts in cardiovascular medicine continued this lively debate.2 This editorial seeks to summarise the key factors relating to the detection and management of HCM in athletes.
CLINICAL MANIFESTATIONS OF HCM
Most of the work following Teare’s description of familial HCM took place in specialty research centres, which focused on patients with the highest burden of disease. These patients were generally young and most often presented with advanced heart failure, prior cardiac arrest, or SCD in an immediate family member. Such work established the classic clinical manifestations of HCM, including exertional chest pain and syncope, heart failure and SCD. This collective early experience led to the notion that HCM, though relatively rare, was a disease of youth commonly associated with significant morbidity and mortality.
In subsequent decades, a combination of heightened awareness and widespread use of non-invasive cardiac imaging revised many of these initial concepts. It is now clear that HCM is typified by its variability. Myocardial hypertrophy may be symmetric or asymmetric and may or may not be accompanied by left ventricular outflow obstruction. Several recent screening studies of asymptomatic subjects suggest that HCM is not rare, and that 1 in 500 Americans has echocardiographic evidence of unexplained left ventricular hypertrophy consistent with HCM.3 Furthermore, although HCM can cause SCD in young people, the disease affects people of all ages, and many people with HCM remain asymptomatic during an entirely normal lifespan.4
REDUCTION OF SUDDEN CARDIAC DEATH