AUTHOR=Ricci Fabrizio , Aquaro Giovanni Donato , De Innocentiis Carlo , Rossi Serena , Mantini Cesare , Longo Francesca , Khanji Mohammed Y. , Gallina Sabina , Pingitore Alessandro 

TITLE=Exercise-induced myocardial edema in master triathletes: Insights from cardiovascular magnetic resonance imaging

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2022.908619

DOI=10.3389/fcvm.2022.908619

ISSN=2297-055X

ABSTRACT=BACKGROUND: Strenuous exercise has been associated with functional and structural cardiac changes due to local and systemic inflammatory responses, reflecting oxidative, metabolic, hormonal, and thermal stress, even in healthy individuals. We aimed to assess changes in myocardial structure and function using cardiovascular magnetic resonance (CMR) imaging in master triathletes early after a full-distance Ironman race.
METHODS: Ten master triathletes (age 45±8 years) underwent CMR within 3 hours after a full-distance Ironman Triathlon race (3.8 km swimming, 180 km cycling, and 42.2 km running) completed with a mean time of 12±1 hours. All triathletes had a 30-day follow-up CMR. Cine balanced steady-state free precession, T2-STIR, tagging, and LGE imaging sequences were performed on a 1.5T MR scanner. Myocardial edema was defined as a region with increased T2 signal intensity (SI) of at least two standard deviations above the mean of the normal myocardium. The extent of myocardial edema was expressed as the percentage of left ventricular (LV) mass. Analysis of LV strain and torsion by tissue tagging included the assessment of radial, longitudinal and circumferential peak systolic strain, rotation, and twist. 
RESULTS: Compared with post-race, biventricular volumes, ejection fraction, and LV mass index remained unchanged at 30-day follow-up. Global T2 SI was significantly higher in the post-race CMR (post-race 10.5±6% vs. follow-up 3.9±3.8%, P=0.004) and presented with a relative apical sparing distribution (P<0.001) matched by reduction of radial peak systolic strain of basal segments (P=0.003). Apical rotation and twist were significantly higher immediately after the competition compared with follow-up (P<0.05). 
CONCLUSIONS: Strenuous exercise in master triathletes is associated with a reversible regional increase in myocardial edema and reduction of radial peak systolic strain, both presenting with a relative apical sparing pattern.