A long duration race induces a decrease of left ventricular strains, twisting mechanics and myocardial work in trained adolescents

Exercise-Induced Cardiac Troponin I Elevation Is Associated With Regional Alterations in Left Ventricular Strain in High-Troponin Responders

BACKGROUND

The implications of exercise-induced cardiac troponin elevation in healthy individuals are unclear. This study aimed to determine if individuals with a high exercise-induced cardiac troponin I (cTnI) response have alterations in myocardial function following high-intensity endurance exercise compared with normal-cTnI responders.

METHODS AND RESULTS

Study individuals were recruited from previous participants in a 91-km mountain bike cycling race (the North Sea Race) and were classified as high- (n=34) or normal-cTnI responders (n=25) based on maximal cTnI values after the recruitment race. The present study exposed all participants to 2 prolonged high-intensity exercises: a combined lactate threshold and cardiopulmonary exercise test and repeated participation in the North Sea Race. Echocardiography was performed before, immediately after, and 24 hours following exercise. All study individuals (n=59) had normal coronary arteries, and were aged 51±10 years; 46 (74%) were men. There were no differences in baseline characteristics between the high- and normal-cTnI responders. Maximal cTnI levels 3 hours after exercise were significantly higher in the high- compared with normal-cTnI group (P<0.001-0.027). Following exercise, there were no differences in global ventricular function between the 2 groups. In contrast, high-cTnI responders had significantly lower regional strain in the anteroseptal segments following exercise, with more profound changes after the race.

CONCLUSIONS

High-cTnI responders had lower anteroseptal segmental strain shortly after exercise than normal-cTnI responders. However, there were no permanent alterations in myocardial strain, indicating no short- or long-term adverse consequences of these exercise-induced alterations in myocardial function.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02166216.

Anthracycline-induced cardiotoxicity on regional myocardial work and left ventricular mechanical dispersion in adolescents and young adults in post-lymphoma remission

BACKGROUND

Myocardial work (MW) is a new echocardiographic tool with a high sensitivity to detect early and subtle alterations of myocardial function. We aimed to evaluate the late effects of anthracyclines by assessing the global and segmental MW and intraventricular mechanical dispersion from speckle tracking echocardiography in childhood lymphoma survivors (CLS).

METHODS

Thirty-one young adults including CLS and age-matched healthy controls were enrolled. All underwent echocardiography including an evaluation of left ventricular (LV) morphology and regional function. We assessed LV longitudinal (differentiating sub-endocardial and sub-epicardial layers), circumferential strains and twist, global and regional MW index (MWI). LV mechanical dispersion was assessed from the time dispersion of LV longitudinal strain, from myocardial wasted work (MWW) and myocardial work efficiency (MWE).

RESULTS

The longitudinal strains both at the level of the sub-endocardium and sub-epicardium were reduced in CLS compared to controls. The global MWI was also decreased (1668 ± 266 vs 1870 ± 264%.mmHg in CLS patients and controls, respectively, p < 0.05), especially on the apical segments. An increase of LV intraventricular mechanical dispersion was observed in CLS. MWW and MWE remained unchanged compared to controls.

CONCLUSION

Our results strongly support that cardiac remodeling is observed in CLS, characterized by a decrease in MW and an increase in LV mechanical dispersion. The apex is specifically altered, but its clinical significance remains uncertain. MW as a complement to strain seems interesting in cancer survivors to detect myocardial dysfunction at early stage and adapt their follow-up.