Detection of subclinical left ventricular dysfunction by tissue Doppler imaging in horses with aortic regurgitation.
Authors: Ven S, Decloedt A, De Clercq D, Vera L, Rademakers F, van Loon G
Journal: Equine veterinary journal
Summary
# Editorial Summary: Tissue Doppler Imaging for Subclinical Left Ventricular Dysfunction in Equine Aortic Regurgitation Aortic regurgitation (AR) is a significant cardiac pathology in horses that can progress to left ventricular failure, yet early detection of functional changes before overt clinical signs emerge remains challenging. Ven and colleagues used tissue Doppler imaging (TDI)—a sensitive echocardiographic technique measuring myocardial wall motion—to compare 34 Warmblood horses with varying degrees of AR against 30 healthy controls, assessing radial wall velocity and deformation across six left ventricular segments during all phases of the cardiac cycle. Horses with AR demonstrated significantly elevated systolic myocardial velocities and increased late diastolic velocities compared with controls across most segments, suggesting compensatory changes in ventricular function that may precede clinical deterioration. Whilst timing intervals between groups showed less consistent variation, these velocity changes potentially represent an objective marker of subclinical dysfunction that could refine clinical decision-making regarding prognosis and exercise restrictions; however, the findings warrant cautious interpretation given the heterogeneous age distribution between groups and the lack of standardised criteria for AR severity grading. Further longitudinal studies are needed to establish whether these TDI parameters predict disease progression and clinical outcomes in affected horses, which would strengthen their clinical utility in monitoring horses with AR before symptoms develop.
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Practical Takeaways
- •TDI can identify subclinical LV dysfunction in horses with aortic regurgitation before overt clinical signs of heart failure develop, enabling earlier intervention
- •Systolic and late diastolic velocity measurements appear more diagnostically useful than timing intervals for detecting AR-related LV changes
- •These findings support using TDI as a complementary diagnostic tool to conventional echocardiography in horses suspected of AR, though clinical prognostic value requires further validation
Key Findings
- •Horses with aortic regurgitation demonstrated significantly higher systolic myocardial velocity compared to healthy controls across most LV wall segments
- •Late diastolic velocity was also elevated in AR horses, though differences were not consistent across all segments
- •Tissue Doppler imaging successfully detected radial myocardial wall motion changes indicative of altered LV function in AR horses
- •TDI timing interval measurements showed less discriminatory value between AR and control groups