Assessment of cardiac variables using a new electrocardiography lead system in horses

Abstract

<jats:p>Aim: The objective of this study was to assess a new lead system method to improve electrocardiographic measurement in horses. Materials and Methods: Twenty-two horses with an average age of 8.8±0.8 years were enrolled in this study. Horses were divided into two groups, consisting of a control group (n=11) and athlete group (n=11). Electrocardiography (ECG) and echocardiography were performed to provide information on the structure and function of the heart. Two lead systems, base apex and modified precordial leads, were used for the electrocardiogram to assess the cardiac electrophysiological functions. Results: PR interval, QT interval, and QRS-T angle presented significant differences between the control and athlete groups when the modified precordial lead system was used. However, significant variations in the mean electrical axis were found when the base apex lead system was used. The modified precordial lead system resulted in more significant differences in cardiac electrophysiological parameters than the base apex lead system. In the athlete group, echocardiography showed cardiac adaptations such as increases in the left atrial and left ventricular dimensions and stroke volume and a decrease in heart rate in response to exercise and training. The observed differences in cardiac morphology and function between groups suggested differences in health performance in the athlete group. Conclusion: These data provided the first evidence that the modified precordial lead system improved statistical variation in ECG recording and provided the most reliable method for health screening in horses.</jats:p>

Electrocardiographic characteristics of trained and untrained standardbred racehorses

“…Previously it has been shown that the QT interval is prolonged in trained horses similar to findings in human athletes 12,54 . We, on the contrary, observed a shortening of the QTc in the trained horses that mostly had monophasic positive T wave deflections whereas the untrained horses primarily had biphasic T waves.…”

The position of ground electrode affects electrocardiographic parameters in horses

“…It was possible that muscle tremors, shivering, and restlessness may be minimized with a ground electrode attached in an unobtrusive place such as the xiphoid position. The P wave was the dominant bifid configuration in the base-apex lead method, similar to previous studies [ 12 , 18 ]. The bifid P wave in horses revealed first the depolarization of the right atrium and subsequently the depolarization of the left atrium.…”

“…The different ECG parameter values in this study are found to be in agreement with previous study conducted by Cherdchutham et al . [ 18 ]. We found that the repositioning of the ground electrodes did not affect the amplitude or duration of P waves and QRS complexes, T duration, and PR interval but did influence the QT interval.…”

“…In this study, P, QRS, T duration, PR and QT interval were within the normal ranges, as reported by Cherdchutham et al . [ 18 ]. The QT interval was significantly lower in the BA1 method than the BA2 method (BA1=0.46±0.04 s and BA2=0.49±0.04 s).…”

“…The second, a modified precordial lead system, was described by some authors like Cherdchutham et al . [ 18 ]. Both of these methods repositioned the limb electrodes to the thorax.…”