Demonstration of regional differences in equine ventricular myocardial velocity in normal 2-year-old Thoroughbreds with Doppler tissue imaging.
Authors: Sepulveda M F, Perkins J D, Bowen I M, Marr C M
Journal: Equine veterinary journal
Summary
# Editorial Summary Doppler tissue imaging (DTI) enables direct assessment of regional myocardial velocity rather than global cardiac function, offering a more nuanced evaluation of ventricular performance than conventional echocardiography. Sepulveda and colleagues examined five distinct regions of the ventricles in 20 clinically normal 2-year-old Thoroughbreds using spectral (SDTI) and colour (CDTI) Doppler techniques, with repeatability testing performed on a single horse across six separate occasions. The left ventricular wall and interventricular septum demonstrated the fastest myocardial velocities, and significant regional differences in peak velocities emerged during systole and early diastole (P<0.05), though not during late diastole; notably, SDTI proved substantially more repeatable than CDTI, particularly for systolic and early diastolic measurements. For equine practitioners, these findings establish baseline velocity parameters in normal young racehorses and demonstrate that SDTI offers a reliable, non-invasive window into regional myocardial function—particularly valuable for detecting early diastolic dysfunction before clinical signs manifest. This technique holds practical promise for both clinical assessment of horses with suspected cardiac disease and for research into how training and athletic demands affect regional myocardial mechanics in performance animals.
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Practical Takeaways
- •Doppler tissue imaging using SDTI modality can be used as a non-invasive clinical tool to assess regional myocardial function and detect early diastolic dysfunction in horses
- •Standardized SDTI examination technique should be developed and validated before clinical implementation for cardiac assessment in individual horses
- •This technique has potential value for research applications and evaluating myocardial dysfunction cases, though further validation in diseased populations is needed
Key Findings
- •Regional differences in myocardial velocity exist within equine ventricles during systole and early diastole but not late diastole (P<0.05)
- •Left region of left ventricle and interventricular septum demonstrate the most rapid myocardial movement
- •Spectral DTI (SDTI) produces repeatable estimates of maximal myocardial velocity in systole and early diastole, while colour DTI (CDTI) shows poor repeatability
- •SDTI and CDTI velocity estimates are not interchangeable and require standardized technique for clinical application