Electrocardiography of functional changes in the myocardium of young cattle with maternal myocardiodystrophy

Abstract

Analysis of the functional capacity of the heart of cattle in terms of modern veterinary development makes it possible to predict myocardial abnormalities both in adult animals and in the young cattle obtained from them. The aim of the research was to study functional changes in the myocardium of young cattle with myocardiodystrophy of mother cows. The study was carried out under the conditions of Kostroma region. Two groups of young cattle of the Kostroma breed aged 14-21 days were formed: the 1st experimental group consisted of heifers from clinically healthy mother-cows (without myocardiodystrophy symptoms) (n=15), the 2nd experimental group consisted of heifers from mother-cows with myocardiodystrophy symptoms (n=5). ECG was recorded on a free-standing animal according to the method of modified leads using veterinary electrocardiograph "Poly-Spectr-8/V" (Russia). ECG was recorded in three standard leads - I, II, III, as well as in three enhanced leads from the limbs aVR, aVL, aVF. ECG was used to determine: duration (ms) of intervals P-Q, R-R, Q-T, QRS complex, increase in the duration of the P wave, position of ST segment relative to isoelectric line, orientation and amplitude/voltage of P, Q, R, S, T waves (mV), position of EOS. It was found that heifers obtained from mother-cows with symptoms of myocardiodystrophy had longer P wave, shorter P-Q, R-R intervals, more significant deviations in SP indices, voltages of P, Q, R, S, T waves in comparison with young cows from clinically healthy mothercows. Electrocardiodiagnostics of myocardial state of young animals obtained from mother-cows with symptoms of myocardiodystrophy reveals in heifers the signs of changes in the main myocardial functions - excitability, conductivity, contractility, manifested as reduced wave volts and prolongation of cardiogram intervals, characteristic for ischemic processes in the myocardium