We appreciate the interest of Dr. Sheikh and colleagues in our study. The issue of whether the electrocardiogram (ECG) is a suitable screening tool for hypertrophic cardiomyopathy (HC) remains controversial, although the current American Heart Association consensus statement on screening does not support incorporating routine electrocardiography as a part of a national preparticipation screening program because of a number of issues, including excessive cost, lack of infrastructure to acquire and interpret large numbers of ECGs by physicians, the uncertain effect of false-negative and false-positive results, and medicolegal concerns. These important limitations appear to also be shared by Dr. Sheikh and colleagues in the United Kingdom, a country that, along with nearly every other country in Europe (except Italy), does not have a mandatory and systematic strategy for preparticipation screening with or without ECGs.

However, if a screening program with ECGs is to be considered, it will be necessary to understand all the potential limitations to such an effort. In this regard, it is difficult to know what affects electrocardiographic screening more—false-negative or false-positive test results. The reported false-positive rate for athlete electrocardiographic screening is about 10%. This would lead to extensive second-tier noninvasive testing that would unavoidably promote inappropriate disqualifications, unnecessary anxiety, and possible chaos in an electrocardiographic screening program.

However, our data highlight the currently underappreciated limitation of false-negative ECGs, which could potentially affect the efficacy and practicality of a screening program in which athletes with HC remain unidentified. This is notable, given that a mandatory national screening program in the United States would involve about 10 million people (even if confined to athletes). With an incidence of 1:500 in the general population, the ECG could miss many athletes each year who would continue in competitive sports, despite a possible risk of sudden death. In addition, the assertion that it would be reasonable for patients with HC and normal electrocardiographic findings to participate in sports because they have a more benign course is simply flawed. No clinical evidence is available to suggest that normal electrocardiographic findings in patients with HC mitigates the risk of sudden death associated with participating in competitive sports, a point that is underscored by the 36th Bethesda Conference guidelines, which have recommended that all patients with HC be excluded from participation in most organized competitive sports, irrespective of the clinical variables, including the electrocardiographic findings.

It would be reasonable to assume that a small number of patients with HC with false-negative electrocardiographic findings would be identified before participation from a positive family history or physical examination findings. However, given the well-accepted principle that the history and physical examination is an inefficient test for identifying many athletes with underlying heart disease (including those with HC), it would therefore be unreasonable to suggest that such examinations alone would be sufficient to reliably raise suspicion of heart disease in all patients with false-negative electrocardiographic findings. Perhaps this point is best understood in the context of the “real world” (to which the authors have alluded), because, recently, 4 high-profile European athletes died suddenly while participating in competitive sports, despite a preparticipation screening examination with electrocardiography.