The position of ground electrode affects electrocardiographic parameters in horses

Abstract

Background and Aim: Improper attachment of the grounding lead is one of the artifacts and causes difficulty in interpretation of ECG. This study aimed to examine the effects of the position of a ground electrode on electrocardiographic (ECG) parameters in horses. Materials and Methods: Sixteen Arabian horses without any cardiac problems were included in this study. The animals were divided into two groups, the base-apex lead method 1 (BA1 method) and the base-apex lead method 2 (BA2 method) with the reposition of the ground limb electrode to the xiphoid. ECG recordings (paper speed=25 mm/s and calibration=10 mm/ mV) were performed to obtain six limb leads (leads I, II, III, aVR, aVL, and aVF). The amplitude and duration of P waves and QRS complexes, PR interval, QT interval, and T duration were analyzed. T wave morphology was observed. Heart rate was evaluated by using R-R interval in each recording. Results: Heart rate, P duration and amplitude, PR interval and T duration, and QRS duration and amplitude were not significantly different between the BA1 and the BA2 method, except that the BA2 method had a significantly higher QT interval than did the BA1 method (p<0.05). A higher significance of the percentage of coefficient of variation was seen on the P wave amplitude and the ORS amplitude in the BA1 method when compared to BA2 method (p<0.05). Conclusion: These data indicated that base-apex lead method with reposition of the ground limb electrode to the xiphoid can decrease variation of ECG configuration and might be useful for routine ECG evaluation and monitoring in horses. The limitation of this study was the evaluation of cardiac morphology and function by echocardiography to exclude cardiac problems. In further, the studies should examine the effect of breed, age, body weight, and sex on electrocardiography parameters in horses.

Evaluation of vasovagal tonus index and electrocardiographic parameters in horses using a new modified base apex lead method

“…Atrial activity may not be optimally recorded using these electrode positions. The other ECG parameters of the modified base apex lead method, identical to previous reports [ 14 , 16 , 17 ], were all normal. Despite the trend of rising QRS duration variation in the modified base apex lead method, the duration proved insignificant for determining ventricular size and, thus, unnecessary for diagnosing equine cardiac hypertrophy.…”

“…This is due to the widespread Purkinje network extending throughout the ventricular myocardium, resulting in multiple points of depolarization across the myocardium, which is different from that observed in humans and small animals [ 12 ]. Optimal electrode positions for good quality ECG recordings have been extensively researched, decreasing movement artifacts and facilitating effortless interpretation [ 16 – 19 ]. The QRS complex amplitude and duration are unrelated to ventricular size.…”

Electrocardiographic Reference Values in Clinically Healthy Lusitano Horses

“…However, to the best of our knowledge, this is the first study describing in detail the electrocardiographic reference values in resting Lusitano horses. In this discussion, we compare our results only with studies where the electrodes’ placement was similar to ours since electrode placement can affect ECG parameters, as previously reported [ 31 ].…”

Effects of pregnancy on electrocardiographic, vasovagal tonus index, and echocardiographic variables in horses

“…For the forelimb, The right atrium (RA) (white) electrode was positioned on the right jugular furrow or in front of right scapula spine and the left atrium (LA) (black) electrode was positioned on 5 th intercostal space, just behind the point of the elbow of the left forelimb. For the hindlimb, the LF (red) electrode was positioned on the loose skin at the left stifle in the region of the patella and the RF (green or grounding) electrode was placed on the skin at the xiphoid as described previously [ 30 ]. Alcohol was applied to improve electrical contact.…”