Echocardiographic Evaluation of Myocardial Function in Standardbreds During the First Year of Race Training.

The research article focuses on a study to observe the effect of race training on the heart function of Standardbred yearling horses, through echocardiographic evaluation.

Objective of the Study

• The main aim of this longitudinal study was to conduct an echocardiographic evaluation of myocardial (heart muscle) velocities and deformation in Standardbred yearlings during their first year of race training. The study’s intent is to provide insights on how athletic activity can impact the function and health of the horse’s heart.

Methodology

• Twelve Standardbred yearlings were selected for the investigation and echocardiographic examinations were conducted at two main points – before the beginning of training and after their first races.
• The echocardiographic tools used in the study were tissue Doppler imaging (TDI) and two-dimensional speckle tracking (2D-ST). These were applied to evaluate the left and right ventricular short axis of the horse’s heart.

Results of the Study

• The study found that radial myocardial velocities – speed of contraction and relaxation of the heart muscles – evaluated using color and pulsed-wave TDI in various parts of the heart wall and the interventricular septum significantly increased over the year of training.
• Specifically, the study observed an increase in early diastolic velocity, relating to the speed at which the heart muscle relaxes to allow blood to flow into the chambers, in the left ventricular free wall and interventricular septum.
• The study also found an increased systolic velocity, relating to the speed of contraction of the heart to push the blood out, in the interventricular septum.
• Further analysis using the 2D-ST found significant increases in radial systolic and early diastolic strain rates in the IVS and an increase in the late diastolic strain rate in the left ventricular free wall. This indicates that changes in the heart muscle’s shape and size during contraction and relaxation have been significantly influenced by training activities.

Conclusion of the Study

• The research concluded that both training and growth had substantial impacts on the horses’ echocardiographic results. Thus, athletic training and age-related development in horses greatly influence their cardiac function.