Author(s): BERRYMAN, B., DOROBANTU, D.M., FRIEDBERG, M.K., PIELES, G.E., WILLIAMS, C.A., Institution: UNIVERSITY OF EXETER, Country: UNITED KINGDOM, Abstract-ID: 1356

INTRODUCTION:
The athletes right ventricle (RV) undergoes remodelling secondary to training, characterised by enlarged end-diastolic volume and augmented myocardial reserve, allowing for increased cardiac output during exercise. Global RV function is determined mainly by transverse and longitudinal function, with transverse proposed to have a greater contribution to global function[1], and this could be of importance during physical activity. This study investigated the relationship between RV function components and exercise intensity in adolescent athletes. It was hypothesised that RV transverse function would increase more than longitudinal function during exercise.
METHODS:
A total of 30 elite male adolescent footballers (mean age 14.9 ± 1.0 y) underwent combined cardiopulmonary exercise test (CPET) and stress echocardiography. Fractional area change (FAC – global function), tricuspid annular plane systolic excursion (TAPSE – longitudinal function) and fractional septal free-wall distance (F-SFD – transverse function) [1] were measured at rest, 0 W, then 50 W increments during exercise. Exercise steps were classified by intensity domain based on the gas exchange threshold (GET) in low (50 W), moderate (below the GET) and high (above the GET). Changes in CPET parameters, RV function and RV cardiac reserve (relative difference in RV function to rest) were analysed using linear mixed models.
RESULTS:
All mean RV function parameters increased from rest to high intensity (FAC: 41 vs. 62.3%, TAPSE: 25 vs 33.5 mm, F-SFD: 20.8 vs 41.4%, p<0.001 for all). Transverse function reserve at high intensity exercise was significantly higher than longitudinal function reserve (mean F-SFD reserve: 126.9%, 95% CI [89.8-164.1] vs TAPSE reserve: 38.4%, 95% CI [27.6-49.3], p<0.05). Mean FAC reserve at high intensity was 54.1%, 95% CI [45.2-63.1]. The absolute difference between TAPSE and F-SFD reserve increased from low to high intensity exercise (p<0.05), while the TAPSE to F-SFD ratio decreased (p<0.05). FAC, TAPSE and F-SFD all demonstrated linear relationships with HR, VO2 and O2 pulse (p<0.05), FAC demonstrated the strongest relationship with each parameter.
CONCLUSION:
As hypothesised, transverse function increased more than longitudinal function during exercise, but FAC correlated best with oxygen uptake. These findings reflect the complex, three-dimensional nature of RV function augmentation in response to exercise. Therefore, assessing only TAPSE and FAC, as commonly conducted in practice, does not fully characterise the global RV exercise response in athletes. A multi-parametric approach should be used, including transverse function reserve.

References
[1] Kind, T, et al., Right ventricular ejection fraction is better reflected by transverse rather than longitudinal wall motion in pulmonary hypertension, J of Cardiovascular Magnetic Resonance, 2010, 12, p.1-11.