Background EKG analysis investigating the impact of the ethnicity on cardiac adaptation to exercise has shown a higher presence of abnormalities, including marked repolarization changes, and signs of left ventricular (LV) hypertrophy in black compared to white athletes. Despite the wide availability of EKG analysis, echocardiographic studies on young black and white athletes is lacking in literature.

Objective Assess the effect in the secondary LV remodelling to load training in young black players compared to matched white players.

Design 4 years longitudinal study.

Setting Sport Medicine outpatients clinic.

Patients 49 young black soccer players (BP) and 50 white matched soccer players (WP) at the first evaluation: BP=13.3±0.58 and WP=13.9±0.50 years.

Interventions Echocardiography and EKG.

Main Outcome Measurements Interventricular septum (IVS) and posterior wall (PW) thickness.

Results No differences in weight, height, blood pressure in maximal ergometry test.

Electrocardiographic repolarization changes were significantly more frequent in BP compared to WP (55% in BP vs 7% of WP). In BP we observed higher level of LV remodelling, consisted in higher LV wall thickness, i.e. higher interventricular septum (IVS) and posterior wall (PW) thickness (IVS: BP=9.99±0.17, WP=9.07±0.14, p<0.001. PW: BP=9.61±0.25, WP=8.85±0.3 mm, p<0.001). At the beginning, BP showed a significantly higher left ventricular remodelling (IVS: BP=9.14±0.6, WP=8.54±0.21 mm, p<0.001. PW: BP=8.98±0.6, WP=8.4±0.26, p<0.001). Afterwards we observed an increase in LV wall thickness and chambers diameters proportionally with the increase in body-size and LV mass. (IVS: BP=10.87±0.23, WP=9.09±0.28 mm, p<0.001. PW: BP=11.69±1.32, WP=9.02±0.24 mm, p<0.001).

Conclusions Also in young blacks athletes we can find an higher cardiac wall thickness compared to their Caucasian peers. This differences remained after 5 years giving probably reason of the fact that those remodelling events happened in the first years of life by genetic factors.