High-Intensity Prolonged Endurance Activity Correlation to Abnormal Cardiac Strain as Measured by Speckle Tracking...

To assess whether there is a dose-dependent relationship between burden of exercise and myocardial strain in endurance runners.

In total, 48 runners were selected based on an exercise questionnaire and after excluding individuals based on preexisting cardiovascular risk factors. Data collection was performed between November 9, 2020 and March 18, 2021. Runners were divided into 2 categories: group A consisted of individuals who had participated in at least 10 ultramarathons and/or Ironman competitions in 10 years (extreme-distance runners); and group B consisted of individuals who have competed in at least 10 marathons over 10 years (marathon-distance runners). Global and regional myocardial strain imaging was performed. Linear regression models were used to assess the relationship between runner groups and global as well as regional myocardial strain.

There was no difference in mean global longitudinal strain between both cohorts. However, there was a statically significant difference in regional myocardial strain in the apical lateral (P =.0027) and apical septal (P=.0022) segments.

Ultramarathoners and Ironman athletes had evidence of regional differences in myocardial strain when compared with runners participating in shorter events, but no difference in global longitudinal strain. The clinical significance of this is not yet clear and additional studies are required.