Continuous electrocardiogram changes preceding phenotypic expression for 8 years in an athlete with hypertrophic cardiomyopathy: a case report

BACKGROUND: Hypertrophic cardiomyopathy is one of the most common causes of sudden cardiac death in young athletes. Performing, comparing, and monitoring serial electrocardiograms over time can help to detect potential cardiovascular diseases and to prevent malignant cardiac events in these populations. CASE PRESENTATION: A young Han Chinese male football player had abnormal electrocardiograms for 8 years without any subjective discomfort. Electrocardiograms revealed that T-wave inversions increased from 1 mm to a maximum of 5 mm on lead I and fluctuated around 5 mm on lead avL. Q-wave duration ranged from 40 ms to 60 ms, its depth increased to a maximum of 8 mm and was much greater than 40% of the R waves in depth in II, III, and avF leads. Echocardiography showed increasingly thickened interventricular septum from 10 mm to 13 mm, enlarged left atrium and ventricle, and reduced left ventricular ejection fraction. Coronary angiography showed no distinct stenosis. Emission computed tomography revealed mild myocardial ischemia of the left ventricular inferior wall. These unusual electrocardiogram manifestations were initially regarded as benign alterations of a highly trained athlete. Upon reviewing the clinical information and the newest criteria for electrocardiographic interpretation in athletes, hypertrophic cardiomyopathy was identified. The misreading of electrocardiograms is not uncommon, thus predisposing such patients to high susceptibility to exercise-induced sudden cardiac death. CONCLUSIONS: We propose that abnormal electrocardiogram findings reveal the initial expression of underlying cardiac diseases such as hypertrophic cardiomyopathy, preceding the symptoms and signs by many years. Accordingly, early detection and continuous surveillance are important for athletes with such electrocardiogram patterns, and improvement of physicians' expertise is crucial.