Diagnostic accuracy of extended-length electrocardiogram in differentiating between athlete's heart and hypertrophic cardiomyopathy

Background: Standard 12-lead electrocardiogram (ECG) has several limitations in solving the differential diagnosis between physiologic left ventricular hypertrophy (PLVH) and hypertrophic cardiomyopathy (HCM), given the high rate of false-positive results in athletes. The aim of this study was to assess the usefulness of several arrhythmic risk indexes in differentiating PLVH from HCM. Methods: A multiparametric ECG analysis (extended-length ECG) was performed on 30 male athletes with PLVH and 30 male patients with HCM, with homogeneous age distribution. Results: The combination of 4 extended-length ECG variables, namely, corrected QT interval (Bazett), QT dispersion, mean resting heart rate, and low-amplitude signal duration at 25 Hz (low-amplitude signal duration at the end of filtered QRS) displayed remarkable diagnostic accuracy (area under receiver operating characteristic curve, 94%). The same accuracy was obtained replacing QT dispersion with T-wave complexity index. Conclusions: Extended-length ECG can be considered an effective, low-cost, and low time-consuming clinical tool for distinguishing between PLVH and HCM.