Normal Electro‐ and Vectocardiographic Data in the Growing Friesian Calf Using a Semi‐Orthogonal Lead System

Abstract

Summary This study derives normal values for electro‐ and vectocardiographic parameters, as generated by the Holmes semi‐orthogonal lead system, in healthy growing calves. Sixty‐four electrocardiograms were recorded from healthy Friesian calves aged from one week to one year. Waveform and duration were analysed and compared in the X‐, Y‐ and Z‐leads. The modal P, QRS and T tridimensional vectors were graphically constructed and their magnitude and orientation were calculated. The duration of waves and intervals were similar to data previously reported in the bovine species. Differences from data reported in other species were attributed to heart rate. The duration of waves and QT and ST intervals significantly lengthened with the decrease in heart rate which occurred during growth. PR interval significantly lengthened with physical maturation, and this change was independent of the decrease in heart rate. The magnitude and the orientation of the spatial modal vectors were approximately similar to the few data previously reported in cattle and in other ungulates and were not affected by somatic growth.

Standard electrocardiographic values in Holstein calves

“…The values for electrocardiographic parameters in calves are similar to those reported by Amory et al (1993). In contrast, the duration of interval segments (PR, QRS and QT) and P waves of normal Holstein cows (DeRoth, 1980) and Jersey cattle (Upadhyay et al, 1976) were longer than calf values in this study.…”

“…In contrast, the duration of interval segments (PR, QRS and QT) and P waves of normal Holstein cows (DeRoth, 1980) and Jersey cattle (Upadhyay et al, 1976) were longer than calf values in this study. This can be explained by the cardiac area enlargement and by the heart rate decreasing that naturally occurs during the animal growth, because these studied parameters, except PR interval, were dependent on heart rate (Amory et al, 1993).…”

“…The potential use of electrocardiography in cattle is well recognized (De Roth, 1980) and limited information exists regarding to the evolution of the electrocardiogram in calves (Amory et al, 1993) because most ECG studies in young animals have been carried out in horses (Lombard et al, 1984;Ayala et al, 1998).…”

Parámetros Electrocardiográficos en Terneros Holstein Criados en la Altura y a Nivel del Mar

“…Las variaciones se justifican porque la actividad eléctrica debe ser significativa para llegar al vértice del corazón durante la activación del complejo QRS (Amory et al, 1993), pero también se asocian a las características anatómicas y fisiológicas del corazón del bovino (Ghiñã et al, 2008a,b). El complejo de Purkinje esté más desarrollado en animales mayores en relación a animales jó-venes (Cunningham, 2003).…”