Effects of exercise in volume overload : insights from a model of aortic regurgitation

Authors: Lachance, DominicChampetier, SergePlante, ÉricBouchard Thomassin, Andrée-AnneRoussel, ÉliseCouët, JacquesArsenault, Marie
Abstract: Background : Aortic valve regurgitation (AR) imposes a pathologic volume overload to the left ventricle (LV), whereas aerobic exercise causes physiologic volume overloading. The impact of combining both LV volume overloads (pathologic and physiologic) is unknown. Considering the known beneficial effects of aerobic training on the cardiovascular system, we hypothesized that the positive effects would outweigh the negative ones and that exercise would improve the tolerance of the LV to AR. Methods : Forty female adult Wistar rats were randomly divided in the following groups: 1) sham sedentary (SS), 2) sham trained (ST), 3) AR sedentary (ARS), and 4) AR trained (ART). Training consisted in treadmill running for 30 min five times per week at 20 m·s−1 for 24wk. In vivo follow-up was made by echocardiography and invasive intracardiac pressure measurements. Hearts were harvested for tissue analysis. Results : Echocardiography revealed less LV dilation and hypertrophy in ART versus ARS as well as improved myocardial performance index. LV ejection fractions remained similar and within normal range in ART versus ARS. Invasive cardiac pressures yielded improved dP/dt− in ART versus ARS but similar dP/dt+. β1-Adrenergic receptor mRNA expression was improved in the ART group versus ARS. Conclusion : Our data suggest that a moderate aerobic exercise program helps minimize LV dilation and hypertrophy and improves diastolic cardiac performance in heart submitted to chronic volume overload due to severe aortic valve regurgitation in this animal model.
Document Type: Article de recherche
Issue Date: 1 June 2009
Open Access Date: 14 November 2017
Document version: AM
Permalink: http://hdl.handle.net/20.500.11794/15826
This document was published in: Medicine and science in sports and exercise, Vol. 41 (6), 1230–1238 (2009)
https://doi.org/10.1249/MSS.0b013e318195b938
Lippincott Williams & Wilkins
Alternative version: 10.1249/MSS.0b013e318195b938
19461544
Collection:Articles publiés dans des revues avec comité de lecture

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