Differentiating hypertrophic cardiomyopathy from athlete's heart: An electrocardiographic and echocardiographic approach

•Differential diagnosis of hypertrophic cardiomyopathy (HCM) from an athlete's heart with mild left ventricular hypertrophy is challenging.•The best diagnostic criteria for HCM was the relative septal thickness ratio (2 x IVS/LV-EDD) > 0.54.•The spatial QRS-T angle > 45 was also useful in the diagnosis of HCM.•No improvement in diagnostic performance was obtained by combining both parameters.

Differential diagnosis of hypertrophic cardiomyopathy (HCM) vs athlete's heart is challenging in individuals with mild-moderate left-ventricular hypertrophy. This study aimed to assess ECG and echocardiographic parameters proposed for the differential diagnosis of HCM.The study included 75 men in three groups: control (n = 30), “gray zone” athletes with interventricular septum (IVS) measuring 13-15 mm (n = 25) and HCM patients with IVS of 13-18 mm (n = 20).The most significant differences were found in relative septal thickness (RST), calculated as the ratio of 2 x IVS to left ventricle end-diastolic diameter (LV-EDD) (0.37, 0.51, 0.71, respectively; p < 0.01) and in spatial QRS-T angle as visually estimated (9.8, 33.6, 66.2, respectively; p < 0.01). The capacity for differential HCM diagnosis of each of the 5 criteria was assessed using the area under the curve (AUC), as follows: LV-EDD < 54 (0.60), family history (0.61), T-wave inversion (TWI) (0.67), spatial QRS-T angle > 45 (0.75) and RST > 0.54 (0.92). Pearson correlation between spatial QRS-T angle > 45 and TWI was 0.76 (p 0.01). The combination of spatial QRS-T angle > 45 and RST > 0.54 for diagnosis of HCM had an AUC of 0.79.The best diagnostic criteria for HCM was RST > 0.54. The spatial QRS-T angle > 45 did not add sensitivity if TWI was present. No additional improvement in differential diagnosis was obtained by combining parameters.