[Optimal sites for attaching ECG-telemetry electrodes on cows and calves]

Comparative ECG telemetry studies were carried out on the proper fixation of electrodes with a view to leading biopotentials from the heart with a total of 185 cows and calves. Conductions were made following the pattern of a standard ECG and the known points for telemetric investigations as suggested by various authors. As optimal sites for fixing the electrodes were shown to be the Ist precordial lead after Gabrashanski, the IInd one after Spörri, the IIIrd one (sagittal) after Roshtevskii, Horma and coll., and the sites suggested by us--apex cordis and the front angle of the left scapula. It was found that best information about the work done by the heart could be obtained by placing the electrodes along the axis line of the heart dipole polarity, and this corresponded to the negative electrode (a red one) of apex cordis--Vth and VIst interrib space at the height behind the elbow processus, and to the positive electrode (a yellow one) of the front angle of the right and the left spadebone. At such lead the basic ECG vector--QRS--was positive, and the peak P and the wave T were negative. The negative charge of the heart dipole was fed to the negative input of the amplifier for biopotentials, and the positive charge of the dipole is fed to the positive input.