Valvular regurgitations, heart murmers and cardiac dimensions in elite eventing horses.

Abstract

OBJECTIVE: To assess the characteristics of heart adaptation and the prevalence of valvular regurgitation and heart murmurs in elite eventing horses. ANIMALS: 14 fit elite (competing at CIC2* level and higher) eventing horses and 15 untrained warmblood horses. METHODES: All horses underwent a physical examination, cardiac auscultation and B-Mode, M- Mode and Colour Flow Doppler echocardiography. Eventing horses were further classified by training intensity and competition level to determine possible intensity effects. RESULTS: Healthy and fit eventing horses had a higher prevalence of valvular murmurs of the aorta, mitral and tricuspid valve than horses that were not trained. Also the prevalence of valvular regurgitations of all the valves detected with Doppler echocardiography was higher in the eventing group than in the control group. Right ventricle diameter (RVD), interventricular septum in diastole (IVSd), calculated left ventricle mass (LVmass) and mean wall thickness (MWT) were significantly higher in eventing than control horses. Competition level groups (control, CIC2* and CCI2*) differed in IVSd, LVmass and MWT while training level groups differed in RVD, IVSd and MWT. CONCLUSION: This group of eventing horses did not show left sided heart adaptations characteristic for volume load. However, the increase in IVSd could be due to strength training or volume load of the right ventricle.