Related Experiment Video
Updated: Jun 23, 2026

Surgically Induced Cardiac Volume Overload by Aortic Regurgitation in Mouse
Published on: August 30, 2022
Effects of exercise in volume overload: insights from a model of aortic regurgitation
Dominic Lachance1, Serge Champetier, Eric Plante
1Research Group in Heart Valve Diseases, Laval Hospital Research Center, University Laval, Quebec, Canada.
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 x s(-1) for 24 wk. 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+. beta(1)-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.
More Related Videos
Related Concept Videos
Aortic Regurgitation I: Introduction
Aortic Regurgitation II: Clinical Features and Diagnostic Tests
Aortic Regurgitation III: Medical Management
Mitral Regurgitation I: Introduction
Aortic Regurgitation IV: Nursing Management
Regulation of Stroke Volume
Preload refers to the degree of stretch on the heart before it contracts. It's analogous to the stretching of a rubber band; the more it's stretched, the more forcefully it snaps back. This concept is encapsulated in the Frank-Starling law of the...

