Abstract
Acute exercise promotes transient exercise-induced cardiac fatigue, which affects the right ventricle and to a lesser extent the left ventricle. Hypoxic exposure induces an additional increase in right ventricular (RV) afterload. Therefore, exercise in hypoxia may differently affect both ventricles. The aim of this study was to investigate the acute effects of a bout of high-intensity exercise under hypoxia versus normoxia in healthy individuals on right- and left-sided cardiac function and mechanics. Twenty-one healthy individuals (mean age, 22.2±0.6years; 14 men) performed 45-min high-intensity running exercise under hypoxia (fraction of inspired oxygen 14.5%) and normoxia (fraction of inspired oxygen 20.9%) in a randomized order. Pre- and post-exercise echocardiography, at rest and during low-to-moderate intensity recumbent exercise ("stress"), was performed to assess RV and left ventricular (LV) cardiac function and mechanics. RV structure, function, and mechanics were assessed using conventional two-dimensional, Doppler, tissue Doppler, speckle-tracking echocardiographic, and novel strain-area loops. Indices of RV systolic function (RV fractional area change, Tricuspid annular plane systolic excursion, RV s', and RV free wall strain) and LV function (LV ejection fraction and LV global longitudinal strain) were significantly reduced after high-intensity running exercise (P<.01). These exercise-induced changes were more pronounced when echocardiography was examined during stress compared with baseline. These responses in RV and LV indices were not altered under hypoxia (P>.05). There was no impact of hypoxia on the magnitude of exercise-induced cardiac fatigue in the right and left ventricles after a 45-min bout of high-intensity exercise. This finding suggests that any potential increase in loading conditions does not automatically exacerbate exercise-induced cardiac fatigue in this setting.
Highlights
Acute exercise promotes transient exercise-induced cardiac fatigue, which affects the right ventricle and to a lesser extent the left ventricle
heart rate (HR) during exercise was matched between exercise under hypoxia and normoxia (172 6 1 and 173 6 2 beats/min, respectively, P = .23)
Mean distance covered during exercise was significantly higher in normoxia (6,655 6 351 m) compared with hypoxia (5,797 6 308 m; P < .001), while there was no significant difference in subjective ratings of perceived exertion
Summary
The aim of this study was to investigate the acute effects of a bout of high-intensity exercise under hypoxia versus normoxia in healthy individuals on right- and left-sided cardiac function and mechanics. The aim of our study was to investigate the impact of a bout of highintensity exercise under hypoxia versus normoxia on EICF on both ventricles
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the American Society of Echocardiography
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
