Evaluation of age-dependent changes of myocardial velocity using pulsed wave and colour tissue Doppler imaging in adult warmblood horses.

The research article investigates how the ageing process affects the heart muscles of warmblood horses, specifically looking at myocardial velocity (the speed of muscle movement in the heart), using two echocardiography techniques known as pulsed wave tissue Doppler (PW-TDI) and colour tissue Doppler imaging (cTDI). The study found that age significantly influences myocardial velocity in horses and that this influence is detectable with both echocardiographic techniques used.

Research Methodology

• A total of 60 healthy warmblood horses, ranging from 3 to 30 years old, were included in the research. The horses were segmented into five age groups for analysis.
• The researchers measured myocardial velocities in three different areas of the horses’ hearts: the right ventricular free wall (RVFW), the interventricular septum (IVS), and the left ventricular free wall (LVFW).
• These measurements were obtained using two different echocardiography methods: pulsed wave tissue Doppler (PW-TDI) and colour tissue Doppler imaging (cTDI).

Findings

• Age significantly affects radial myocardial velocity, the speed of muscle movement in different regions of the heart.
• The left ventricular free wall (LVFW) shows a decrease in the speed of systolic contraction and early diastolic relaxation as horses age, whereas the velocity of late-diastolic contraction increases.
• Meanwhile, the interventricular septum (IVS) shows significant increases in early and late diastolic contraction velocities.
• The right ventricular free wall (RVFW) also experiences an increase in the velocities of systolic and late-diastolic contraction as ageing occurs.
• Both echocardiographic assessment methods — PW-TDI and cTDI — detected these age-dependent changes, but PW-TDI showed a lower intraindividual variation coefficient, suggesting higher reproducibility.

Implications

• The research suggests that the heart’s contraction ability decreases and myocardial relaxation reduces in the left ventricle while the diastolic function alters in the right ventricle as horses age.
• Such functional changes may point to age-related structural changes in heart muscles or cardiac remodelling, such as increased myocardial stiffness.
• It is therefore essential to account for these age-dependent physiological changes when assessing a horse’s heart’s radial myocardial velocities using tissue Doppler imaging (TDI).
• While the two echocardiography techniques used yielded comparable findings, PW-TDI provided relatively higher values than cTDI.