Electrocardiographic changes induced by physical exercise in the jumper horse

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.