Evaluation of electrocardiograms on Polish ponies

Polish ponies are an endemic Polish breed of horses, revived from the small population, which survived the World War II. This breed is raised in such a way as to reduce the negative influence of inbreeding, but also to streng then the advantageous characteristics of the breed. The experimental group consisted of 28 healthy Polish ponies. After collecting the anamnesis and t he clinical examination electrocardiography was performed after rest and st ress, the latter induced by a half-hour of trotting or galloping. Electroca rdiography was performed with the aid of a Multicard E-30 machine with 9 le ads. Neither force (nose twitch) nor pharmacological sedation were used. Pa thological arrhythmias were not noted in any of the examined horses. Statis tically important differences were observed between the stress and rest ele ctrocardiographs of the Polish Denies. A heart rate increase from 50 to 80 per minute was observed after the effort. Considering the frequencies of oc currence, the following types of the P waves were noted in the Polish ponie s: positive, negative, double-phased, isoelectric, variable. They were repr esented as the shortened P wave (statistically significant only in the II, aVR i CV4), PQ and QT intervals and ST segment. The P wave in the stress el ectrocardiography altered from the double-phased wave to the positive one. The times and amplitude of Q, R, S complex were not significantly different while the ST segment and QT decreased significantly. In conclusion, it can be claimed that the stress electrocardiogram for the Polish ponies is sign ificantly different fr om the rest one on account of an increase in heart a ction shortening the P wave, PQ and QT intervals and ST segment.