Electrocardiographic changes induced by physical exercise in the jumper horse

Abstract

The authors conducted an electrocardiographic investigation on eight jumpers of Sella Italiana breed to evaluate cardiovascular changes associated with specific competitions. Electrocardiographic recordings were carried out using an electrocardiograph with a deflection of 10 mm/mV and a paper speed of 25 mm/sec. Recordings were conducted under the following experimental conditions: at rest, after warm up, after a jumping trial, and 15 and 30 minutes after the end of the trial. Significant reductions were observed in the duration of the P wave, of the P-Q interval, and of the R-R intervals immediately after the test. Significant elevations were observed immediately after the test in the range of the T and P waves of the heart rate. The observed changes can be attributed mainly to increase of the sympathetic tone connected with increase of heart rate necessary to satisfy the elevation of the cardiac range. These results are useful to plan and monitor specific training programmes.

Electrocardiographic patterns of Mangalarga Marchador horses before and after implementation of the marcha gait

“…Despite significant reduction in the QT interval after the marcha gait, it was possible to observe a significant increase in QTc, indicating alterations in ventricular repolarization. This significant increase in QTc reported after physical activity was not observed by FAZIO et al (2003), but was also described by PICCIONE et al (2003) and BELLO et al (2012). According to PICCIONE et al (2003), such finding is due to an increase in autonomic tonus.…”

Physical and electrocardiographic evaluation of horses used for wagon traction

“…Sinus arrhythmia and sinus tachycardia may be observed in healthy horses and be consequence of the increase in vagal tone and animal manipulation, respectively (Radostits et al, 2002;Fernandes et al, 2004;Mantovani et al, 2013). On the other hand, sinus tachyarrhythmia, noted in control (10%) and wagon traction (4%) groups (Table 2), has not been described as a normal rhythm for horses and could be related to the cardiovascular conditions of these animals.…”

“…Splitting of second cardiac sound (S2) is a result of asynchronous closure of semilunar valves and is considered common and physiological in healthy horses, occurring after variations in the HR and respiration (Radostits et al, 2002;Schwarzwald, 2013).…”

“…Differences observed between wagon traction and athlete groups were higher amplitude of T (+) (in LII) and S (-) (in base-apex) waves in wagon traction group. T wave amplitude increase was described in healthy horses undergoing physical exercise (Piccione et al, 2003;Pedersen et al, 2013) or as a consequence of HR increase (Bonagura et al, 2010). Dumont et al (2010) reported that higher S (-) amplitude, after prolonged exercise, was probably related to a right ventricular hypertrophy.…”

“…Thereby, ECG can be better tolerated diminishing animal excitement and artifacts during the evaluation (Bonagura et al, 2010). However, the bipolar leads are widely used for the study of electric vector direction in the heart (Radostits et al, 2002).…”