Alterations in echocardiographic and electrocardiographic features in Japanese professional soccer players: Comparison to African-Caucasian ethnicities

Background: Scarce data are available regarding the electrocardiographic (ECG) and echocardiographic changes in athletes of Asian origin. Design: We investigate the ECG and echocardiographic patterns in Japanese (J) compared with African-Caribbean (AC) and Caucasian (C) athletes. Methods: A total of 282 professional soccer players (68 J, 96 AC and 118 C) matched for age, gender, sport and level of achievement was examined. Results: ECGs were without alterations in 62% of J (versus 69% of C, non significant and 44% of AC, p<0.001). The most common alterations in J were sinus bradycardia (69%), incomplete right bundle branch block (RBBB; 43%), early repolarization (18%), isolated increase in R/S-wave (10%), Q-waves (9%). Remarkably, no J athlete showed deeply T-wave inversion, in contrast to 6% of AC (p<0.05). Occasionally, J showed J-point upward/domed ST-elevation with inverted/ biphasic T-wave (6% versus 16.5% in AC, p<0.01). J demonstrated larger left ventricular (LV) cavity compared with AC and C players (55.2±3.3 versus 52.2±3.8 and 53.9±3.7 mm, respectively, p<0.01), with an important subset (≥4%) presenting a markedly enlarged cavity (≥60 mm), in the presence of normal systolic/diastolic function and no segmental abnormalities. Therefore, J showed a more eccentric remodelling compared with AC and C (relative wall thickness: 0.31±0.05, 0.38±0.06 and 0.36±0.06, respectively, p<0.01). Conclusion: J players show the most eccentric LV remodelling compared with C and AC players. In association, certain training-related ECG patterns, i.e. sinus bradycardia and isolated increase in R/S-wave voltage, are present in a larger proportion of J players than previously described in C players. Conversely, no J athlete showed deeply T-wave inversion, as commonly found in AC and occasionally in C.