Physiological assessment of left ventricular size indexed by peak oxygen uptake across sporting disciplines

Left ventricular (LV) enlargement is a common training-induced adaptation in athletes, particularly in endurance sports. Previous research indicates that indexing LV volumes and mass to absolute peak oxygen uptake (VO₂_peak) better reflects physiological adaptation than traditional indexing to body surface area (BSA). Therefore, we investigated whether indexing LV end-diastolic volume (LVEDV) and mass to VO_2peak could eliminate differences in LV size among athletes from different sport categories (endurance, mixed, power, and technical).

This analysis included 70 athletes from the multicenter COSMO-S in Germany and 15 elite endurance athletes from Norway. All participants (29 ± 8 years, 52 male) underwent echocardiography and cardiopulmonary exercise testing. In regression analyses, VO_2peak (L/min) accounted for a significantly greater proportion of the variance in LVEDV than BSA (R² 0.64 vs. 0.19, P < 0.001), while this difference was not significant for LV mass (R² 0.54 vs. 0.36, P = 0.06). When indexed to BSA, both LVEDV and LV mass revealed significant differences across sports (both P ≤ 0.019), that disappeared when indexed to VO₂_peak (all P ≥ 0.40). In a cohort of 12 dilated cardiomyopathy (DCM) patients serving as a pathological reference group, indexing LVEDV and LV mass to VO_2peak better differentiated DCM patients from athletes than indexing to BSA.

Indexing LV size to VO₂_peak may provide a more physiological interpretation of cardiac adaptations in athletes and reduce sport-specific differences due to better consideration of training-induced adaptations. These findings should be replicated in larger cohorts and tested for the ability to detect subtle pathologies.