It’s Electric: The Utility of the Screening ECG for Sports Physicals

With warmer weather, young athletes of all ages will need sports physicals. One controversial area related to sports preparticipation evaluation is the use of the screening electrocardiogram (ECG).  

Sudden cardiac death (SCD) is the leading cause of death in athletes during sports participation. SCD affects children in a bimodal distribution, first spiking in early childhood and again in adolescence. Boys are affected more than girls in a 2:1 ratio.¹ An ECG can screen for risk factors for sudden cardiac death. For example, an ECG can detect signs of hypertrophic cardiomyopathy. It also can detect long QT syndrome, which predisposes children toward torsades de pointes and ventricular tachycardia. In many European countries, including Italy and Switzerland, the use of routine ECG is standard for sports physicals.^2,3 This article reviews the value, including the limitations, of this screening modality.  

In its 2014 consensus statement, the American Heart Association (AHA) did not recommend routine screening ECGs in pediatric patients 12 to 25 years of age, considering the low incidence of SCD.⁴ However, the incidence of SCD is challenging to estimate due to the wide variation in populations used in different studies (i.e., the general population, only athletes or only competitive athletes). The AHA did highlight several findings that show that a patient’s medical history, family history and physical exam can dictate the need for an ECG. The AHA recommends the use of 14-point checklist. In the medical history, concerning findings include chest pain with exertion, unexplained syncope, excessive dyspnea with exercise, history of a heart murmur, prior sports participation restriction and history of elevated systemic blood pressure. In the family history, concerns include premature death or disability before age 50 related to heart disease, cardiomyopathy, long QT syndrome or channelopathies. Last, in the physical exam, femoral pulse abnormalities, elevated brachial artery blood pressure, heart murmurs and stigmata of Marfan syndrome suggest the need for ECG screening.⁴ 

In 2019, the 14-point AHA screening tool was compared to routine ECG for screening high school athletes. One or more responses to the AHA questionnaire were positive in 814/3620 (22.5%) athletes. ECG abnormalities were found in 103/3620 (2.8%). Echocardiography was performed in those with a positive questionnaire or ECG findings to serve as the gold standard. The AHA questionnaire had a sensitivity of 18.8%, specificity of 68.0% and positive predictive value of 0.3%, lower than the sensitivity (87.5%), specificity (97.5%) and positive predictive value (13.6%) of ECG.⁵ An important limitation was that echocardiography was not performed on all participants, so the negative predictive value could not be reported, and structural heart disease may have been underreported.  

More recently, studies in Italy and Switzerland have supported the use of routine screening ECG.^2,3,6 Notably, the Swiss study examined only patients who competed in more than six hours of high-level athletic activity per week.³ Italy has a higher incidence of SCD attributable to arrhythmogenic right ventricular cardiomyopathy, while the United States has a higher incidence of hypertrophic cardiomyopathy.⁷ When reviewing the evidence, it is important to note the study design and the study populations to determine applicability.  

One limitation of the screening ECG is the challenge of interpretation. An ECG may show normal variants in children not typically seen in adults. It may also reveal physiologic adaptations in athletes. Anterior T wave inversion is a common finding in female athletes, likely secondary to chest wall anatomy,⁸ and also athletes of color.⁹ Early repolarization (defined as a higher QRS voltage and shorter QRS duration) is more commonly seen in male than female athletes.^10,11 Neither of these two phenomena are associated with increased risk of arrythmia in children.^8-10 An ECG should be interpreted with the patient’s age and level of physical activity in mind. In 2017, international recommendations provided guidance specific to ECG interpretation in athletes.^11,12 

A thorough history and physical exam can often detect indications for an ECG or other testing in pediatric athletes prior to sports participation.⁴ A screening ECG may identify additional patients at risk of SCD. However, the high rate of false positives with routine ECG use may lead to costly downstream testing and unnecessary exclusion of athletes from sports participation.⁷ While the screening ECG remains controversial, the importance of Basic Life Support (BLS) remains critical. At schools, camps and athletic events, effective BLS with access to and trained use of automatic external defibrillators will save more lives than screening ECG.¹