Published in:
Open Access 01-07-2018 | Invited Review
Left ventricular function and mechanics following prolonged endurance exercise: an update and meta-analysis with insights from novel techniques
Published in: European Journal of Applied Physiology | Issue 7/2018
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Background
The cardiac consequences of undertaking endurance exercise are the topic of
recent debate. The purpose of this review is to provide an update on a growing
body of literature, focusing on left ventricular (LV) function following
prolonged endurance exercise over 2 h in duration which have employed novel
techniques, including myocardial speckle tracking, to provide a more
comprehensive global and regional assessment of LV mechanics.
Methods
Prospective studies were filtered independently following a pre-set criteria,
resulting in the inclusion of 27 studies in the analyses. A random-effects
meta-analysis was used to determine the weighted mean difference and 95%
confidence intervals (CI) of LV functional and mechanical data from
pre-to-post-exercise. Narrative commentary was also provided where volume of
available evidence precluded meta-analysis.
Results
A significant overall reduction in LV longitudinal strain (Ɛ) n = 22
(− 18 ± 1 to − 17 ± 1%; effect size (d) − 9:
− 1 to − 0.5%), strain rate n = 10 (SR;d − 0.9: − 0.1.3 to − 0.5 l/s) and twistn = 5 (11.9 ± 2.2 to 8.7 ± 2.2°,d − 1: − 1.6 to − 0.3°) was observed
following strenuous endurance exercise (range 120–1740 min) (P < 0.01). A smaller number of studies
(n = 4) also reported a non-significant
reduction in global circumferential and radial Ɛ (P > 0.05).
Conclusion
The meta-analysis and narrative commentary demonstrated that a reduction in LV
function and mechanics is evident following prolonged endurance exercise. The
mechanism(s) responsible for these changes are complex and likely
multi-factorial in nature and may be linked to right and left ventricular
interaction.