Regular exercise improves health and leads to cardiac remodeling known as the athlete’s heart.
However, emerging data suggest that exercise-related pressure and volume overload may result in
detrimental remodeling of the right ventricle (RV) or atria. This has been linked to arrhythmias and
sudden death in athletes.
In this project, the horse will be used as an animal model for exercise-induced cardiac remodeling as
this species shows an extremely high cardiac output, with high RV and atrial pressures. Like athletes,
trained racehorses show enlarged RV dimensions and a relatively high prevalence of atrial
fibrillation and sudden death. However, the relationship between echocardiographic evidence of RV
and atrial dysfunction and myocardial damage has not yet been explored.
First, RV function will be characterized in healthy horses at rest and during stress testing.
Next, the influence of acute and chronic pulmonary hypertension on RV function and structure will
be investigated using echocardiography, cardiac biomarkers and myocardial biopsies. Finally, the
impact of a four-month training period and a bout of intense exertion on RV and atrial function and
structure will be examined.
This research will undoubtedly provide new insights into the pathophysiology of athlete’s heart and
pro-arrhythmic remodeling in man and horse. In addition, data from this study can be used as
diagnostic or prognostic parameters in horses with cardiac or pulmonary disease and poor
performance.