Superior cardiac mechanics without structural adaptations in pre-adolescent soccer players

Abstract

Aims: This study aimed to evaluate left ventricular (LV) structure, function and mechanics, in highly-trained, pre-adolescent soccer players (SP) compared to age- and sex-matched controls (CON).

Design: The study design was a prospective, cross-sectional comparison of LV structure, function and mechanics.

Methods: Twenty-two male SP from two professional youth soccer academies (age: 12.0±0.3 years) and twenty-two recreationally active CON (age: 11.7±0.3 years) were recruited. Two-dimensional conventional and speckle tracking echocardiography were used to quantify LV structure, function and peak/temporal values for LV strain and twist, respectively.

Results: End-diastolic volume index was larger in SP (51 ± 8 mm/(m2)1.5 vs. 45 ± 6 mm/(m2)1.5; p=0.007) and concentricity was lower in SP (4.3 ± 0.7 g/(mL)0.667 vs. 4.9 ± 1.0 g/(mL)0.667; p=0.017), without differences in mean wall thickness between groups (6.0 ± 0.4 mm vs. 6.1 ± 0.5 mm; p=0.754). Peak circumferential strain at the base (-22.2 ± 2.5% vs. -20.5 ± 2.5%; p=0.029) and papillary muscle levels (-20.1 ± 1.5% vs. -18.3 ± 2.5%; p=0.007) were greater in SP. Peak LV twist was larger in SP (16.92 ± 7.55º vs. 12.34 ± 4.99 º; p=0.035) and longitudinal early diastolic strain rate was greater in SP (2.22 ± 0.40 s -1 vs. 2.02 ± 0.46 s -1; p=0.025).

Conclusions: Highly-trained SP demonstrated augmented cardiac mechanics with greater circumferential strains, twist and faster diastolic lengthening in the absence of differences in wall thickness between SP and CON.