Electrocardiographic parameters in the normal lactating Holstein cow.

Abstract

Electrocardiographic parameters in the normal lactating Holstein cow have been measured, computed and analyzed. The study was conducted on 32 animals of a mean age of 4.7 years. The recordings of the 12 leads (I, II, III, aVR, aVL, aVF, CV(6)LU, CV(6)LL, CV(6)RL, CV(6)RU, V(10) and base-apex) were made with a three channel electrocardiograph calibrated at 20 mm/mV and 25 mm/s. Conduction parameters, waves, intervals and segments have been measured. The recordings were analyzed as to shape, polarity and amplitude of the P and T waves and the components of the QRS complex. The results are discussed in respect to the morphophysiological characterestics of the bovine heart.