Evaluation of age-dependent changes of myocardial velocity using pulsed wave and colour tissue Doppler imaging in adult warmblood horses.
Authors: Gehlen Heidrun, Bildheim Lisa-Marie
Journal: Journal of animal physiology and animal nutrition
Summary
# Editorial Summary: Age-Related Changes in Equine Myocardial Function Gehlen and Bildheim used tissue Doppler imaging to investigate how ageing affects heart muscle velocity in 60 healthy warmblood horses across five age groups (3–30 years), measuring contractility and relaxation in three distinct regions: the right ventricular free wall, interventricular septum, and left ventricular free wall. Pulsed wave tissue Doppler imaging (PW-TDI) proved more reproducible than colour tissue Doppler imaging (cTDI), though both techniques detected significant age-related changes. The left ventricle showed declining systolic contraction velocity and early diastolic relaxation velocity with age, whilst the right ventricle and septum demonstrated compensatory increases in systolic and diastolic velocities—changes consistent with myocardial stiffening and altered diastolic function rather than frank pathology. For practitioners evaluating equine cardiac performance via echocardiography, these findings underscore the critical importance of applying age-appropriate reference ranges when assessing myocardial velocities, particularly in older competition horses or geriatric patients where physiological remodelling may be misinterpreted as disease if baseline age-related norms are not considered.
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Practical Takeaways
- •Cardiac ultrasound interpretation using tissue Doppler must account for physiological age-related changes in myocardial velocity; what appears abnormal in a young horse may be normal in an older horse
- •Older horses show progressive deterioration in left ventricular function with aging, which may explain reduced exercise tolerance and stamina in geriatric animals
- •When performing echocardiographic evaluations, PW-TDI offers better measurement reproducibility than cTDI for assessing myocardial velocities and should be preferred for serial monitoring of cardiac function
Key Findings
- •Systolic contraction velocity and early diastolic relaxation velocity in the left ventricular free wall decreased significantly with age (p≤0.01 and p≤0.001 respectively)
- •Late diastolic contraction velocity increased with age in both interventricular septum and right ventricular free wall (p≤0.001)
- •Pulsed wave tissue Doppler imaging (PW-TDI) showed higher reproducibility than colour tissue Doppler imaging (cTDI) with lower intraindividual variation coefficients
- •Age-related changes suggest decreased left ventricular contractility, reduced myocardial relaxation, and possible myocardial stiffness in aging horses