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Sudden cardiac death (SCD) is the leading cause of mortality in young athletes during exercise and is triggered by intense exertion in those individuals with occult cardiovascular abnormalities.1 All major medical and sporting organisations recommend cardiovascular screening prior to competitive athletics.2–5 As such, primary care physicians routinely perform preparticipation physical examinations with the goal of promoting health and safety in the athlete. Regardless of the often-polarising debate surrounding the inclusion (or not) of an ECG to the traditional history and physical examination, it is crucial for physicians to avoid minimising findings that may be suggestive of cardiac pathology in an effort to appropriately identify affected individuals. Widely available cardiovascular disease (CVD) treatments and therapies can lead to significant prevention in morbidity and mortality.
Warning! warning! family history of SCD <35 years old
In a recent article, Ranthe et al 6 presented findings from a large controlled epidemiological study of family members related to SCD victims from Denmark. The authors identified all SCD victims aged 1–35 between 2000 and 2006 and prospectively compared the standardised incidence ratios (SIRs) of CVD in their first and second-degree relatives with that of the background population. In the 11-year follow-up period, the SIR was highest among first-degree relatives <35 years old in which the risk for cardiomyopathy and ventricular arrhythmias was an astounding 17.91 and 19.15, respectively. Importantly, the risk of SCD in relatives was the highest within the first year following SCD (SIR=11.13).
Results from this study demonstrate the importance of a thorough and adequate family history when screening for SCD. Although the majority of young athletes who suffer a cardiac event are asymptomatic prior to cardiac arrest, there is a small subset of individuals who provide warning signs or symptoms of the underlying CVD.7 While the answers to many personal history elements are subjective and rely heavily on compliance or the ability to understand the medical nature of the questions, a family history of SCD in an individual <35 years is more concrete and identifiable. These individuals should undergo a more comprehensive cardiac evaluation to identify potentially lethal cardiac disease.
Cardiovascular screening: improving our family history questions
Preparticipation screening aims to identify athletes with occult CVD who are at risk for SCD during exercise. Regardless of the screening strategy utilised, sports physicians must be aware of concerning personal or family history, as well as athlete-specific ECG interpretation criteria that can aid in the detection of individuals at risk for SCD. Early disease recognition may lead to risk reduction through appropriate medical management.
Many comprehensive history questionnaires have been proposed.2 ,3 ,8 Unfortunately, little is known about the positive and negative-predictive value of these screening questions, and questions that are too broad risk a high frequency of false-positive responses. In the USA, both the American Heart Association and the Pre-Participation Physical Evaluation Monograph recommend asking athletes about a family history of heart problems or sudden death in any relative <50 years old.2 ,8 Our experience suggests that this age cut-off yields a large number of false-positive responses with athletes reporting cardiac-related events in family members with atherosclerotic coronary artery disease (CAD). While this is an important detail in the long-term care of an athlete, CAD is seldom the cause of SCD in young athletes undergoing a preparticipation evaluation, and SCD from very premature CAD in a family member will still be flagged even with a younger age cut-off. The goal of investigating the family history in the setting of cardiovascular screening in athletes is to identify athletes at higher risk for an inherited cardiovascular disorder (ie, cardiomyopathy or ion channelopathy). A narrower age cut-off may improve the specificity of these questions without losing relevant sensitivity.
As cardiovascular screening advances beyond consensus guidelines and towards more evidence-driven recommendations, it seems Ranthe and colleagues have provided a good starting point to make our history questions more accurate. A family history of SCD in a relative <35 years old deserves our utmost attention.
Contributors IMA and JAD drafted pieces of the manuscript and reviewed its contents for accuracy.
Competing interests None.
Provenance and peer review Not commissioned; internally peer reviewed.
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