Electrocardiographic studies on adult cattle

European Biotechnology Congress

Hilton Hotel, Bucharest, 

May 7 - 9, 2015

Electrocardiographic studies on adult cattle

Brăslașu C.M., Daniela Elena Brăslașu, Simiz Fl., Ghiță M.,

Tudor Poliana, Cotor G.

Faculty of Veterinary Medicine, Bucharest

cbraslasu@gmail.com

The cardiac arrhythmias are affections that can be traced on cardiac and noncardiac diseasses as well. Considering this, it is important to discover the normal values of the ECG components on this specie. Thus this paper will try to establish what are these values. Research was performed on a number of 207 clinically healthy cows (metis breed Holstein; age ranging between 4 to 8 years old and weight between 400 to 450 kgs).The work parameters were: unipolar and bipolar leads proposed by Dubois (the first two exploratory electrodes behind the scapulohumeral joint, the third was placed ventral, behind the xiphoid process, the amplitude, 1 mV=10 mm and the speed was of 25 mm/sec. The bovines’ electrocardiography shows P and T waves on the opposite side of the ventricular complex, the values of the ECG components (II-lead - Average/SD) were: A) the amplitude (mV) of the P wave = 0.177/0.059, the amplitude of the ventricular complex = 1.181/0.27 and the amplitude of the T wave = 0.453/0.15. B), the duration (sec.) of the P wave = 0.085/0.01,  P – R interval = 0.199/0.02, ventricular complex = 0.081/0.01, Q-T interval = 0.383/0.04, T wave = 0.095/0.02, R-R interval = 0.784/0.12, P-T interval = 0.584/0.06, TP segment = 0.195/0.09 and heart rate = 78.43/12.13. Mean electric axes (ventricular complex) was = - 85,17/8,71 degrees.  Compared to the previous studies that examined 82 animals, the values displayed by the ECG components were relatively the same and the duration was similar to those studied before.

The electrocardiography is a method frequently used in the diagnosis of cardiovascular diseases such as arrhythmias, while offering useful information for the diagnosis of the enlargement of the heart cavities, pericardial collection, electrolyte disturbance etc.

However, when performing the electrocardiogram on cattle in three standard limb leads, it does not offer an adequate tracing. Thus, more leads systems were proposed. We studied Dubois system that, compared to the standard limb leads,  provides a “clean” trace, with amplitude waves easy to evaluate, while the practical registration is simply performed.

The present study aimes to estimate the duration and amplitude of the ECG components in adult cows, clinically healthy.

Material  and  Methods

Research was performed on a number of 207 clinically healthy cows, metis breed Holstein; age ranging between 4 to 8 years old and weight between 400 to 450 kg.

The ECG were performed on animals in quadrupedal position, restrained by simple binding.

The work parameters were: the amplitude of the millivolt = 10 mm and the paper speed was 25 mm/sec.

The sites for electrodes application was not sheared but only moisten with alcohol solution. The cable were attached  with alligator clips.

The suitable sites for the attachments of the exploring electrodes were:

-         Red electrode (right anterior limb) – anterior of the right shoulder;

-         Yellow electrode (left anterior limb) – in front of the left shoulder;

-         Green electrode (left posterior limb) – ventral, on the midline, between the xiphoid process and umbilicus;

-         Black electrode (indifferent connection) – outside the triangle formed by the other three exploring electrodes (on the neck side) (figure 1).

Figure 1. Dubois leads system

Results and Discussion

The study analyzed:

-         The values of the ECG components in Dubois leads system;

-         Changes of the ECG values indifferent physiological conditions.

The bovines’ electrocardiography shows P and T waves positive in the opposite side of the ventricular complex (see Figure 2).

Figure 2.  The cattle`s electrocardiogram

.

The values of the components in Dubois system, in adult cows, are shown in table 1 – 3.

Table 1. Amplitude of ECG waves in Dubois system in adult cows

(n. = 207)

mV		I.	II.	III.	“aVR”	“aVL”	“aVF”
P wave	n. Average S. deviation	114 0.029 0.040	199 0.177 0.059	198 0.136 0.044	190 0.106 0.060	186 0.043 0.066	196 0.158 0.044
Ventricular complex	n. Average S. deviation	153 0.179 0.122	204 1.176 0.279	203 1.217 0.286	198 0.535 0.192	199 0.706 0.189	200 1.235 0.282
T wave	n. Average S. deviation	117 0.038 0.050	202 0.453 0.160	203 0.450 0.152	195 0.215 0.070	196 0.215 0.073	198 0.464 0.155

Table 2. Duration of ECG components in Dubois system in adult cows

(n.= 207)

Duration (sec.)
P wave	n. Average S. deviation	204 0.085 0.013
P-R interval	n. Average S. deviation	204 0.199 0.025
Ventricular complex	n. Average S. deviation	206 0.081 0.011
Q-T interval	n. Average S. deviation	206 0.383 0.040
T wave	n. Average S. deviation	205 0.095 0.021
R-R interval	n. Average S. deviation	205 0.784 0.121
P-T interval	n. Average S. deviation	203 0.584 0.068
TP segment	n. Average S. deviation	203 0.195 0.096
Heart rate	n. Average S. deviation	205 78.430 12.131

Table 3. Values of the electrical axes in Dubois system in adult cows

(n. = 207)

Electrical axes (°)
P wave (+)	n. Average S. deviation	200 76.645 14.326
Ventricular complex (-)	n. Average S. deviation	201 85.174 8.716
T wave (+)	n. Average S. deviation	200 89.925 9.523

The electrical axes extreme deviation (changing the sense) were excluded

During the examination we noticed the following situations:

When the animal adopted sternal position, the values of ECG components, especially those of the amplitude, changed as a consequence of changing the heart electrical axes (as the heart topography in the thorax changes when the animal is lying down).

Another situation was noticed when the position of the head and the neck has been changed. Turning the head to the left or right visibly modifies the amplitude of ECG trace and less the heart rate, which can be accounted to the compression of carotid sinuses.

During the examination, the position of the electrodes was changed. They were attached in a lateral or more anterior position, describing a circle of approximate 10 cm diameter. No changes of the wave amplitude were noticed.

When feeding the animal, the heart rate slightly increased as a consequence of the sympathetic system stimulation.

Electrical axes were positive for P and T waves and negative for the ventricular complex. We noticed positive ventricular  complex in 6 animals.

Conclusions

   1.     ECG exam was performed on a number of 207 clinically healthy cows, metis breed Holstein; age ranging between 4 to 8 years old and weight between 400 to 450 kgs.

   2.     The work parameters were: unipolar and bipolar leads proposed by Dubois (the first two exploratory electrodes behind the scapulohumeral joint, the third was placed ventral, behind the xiphoid process, the amplitude, 1 mV=10 mm and the speed was of 25 mm/sec.

    3.     The bovines’ electrocardiography shows P and T waves positive in the opposite side of the ventricular complex.

    4.     The values of the ECG components (II-lead; Average/SD) were: A) the amplitude (mV) of the P wave = 0.177/0.059, the amplitude of the ventricular complex = 1.181/0.27 and the amplitude of the T wave = 0.453/0.15. B) the duration (sec.) of the P wave = 0.085/0.01,  P – R interval = 0.199/0.02, ventricular complex = 0.081/0.01, Q-T interval = 0.383/0.04, T wave = 0.095/0.02, R-R interval = 0.784/0.12, P-T interval = 0.584/0.06, TP segment = 0.195/0.09 and heart rate = 78.43/12.13. Mean electric axes (ventricular complex) was = - 85.17/8.71 degrees.

     5.     Several physiological aspects (such as the cattle turning the head to the left or to the right ), alimentation, the cattle laying on a sterno-abdominal decubitus, etc. lead to minor alterations of the amplitude of the ECG waves that carry no clinical significance.

References

1.     Amory H., Genicot B., Rollin F., Beduin J.M., Lekeux P., 1993 - Normal electro- and vectorcardiographic data in the growing Friesian calf  using a semi-orthogonal lead system. Zentralbl Veterinarmed A., 40, 2, 81 - 92.

2.     Blood D.C.,  Henderson  J.A., 1983 – Veterinary Medicine. Ed. IV., Bailiere Tindall, London.

3.     Brăslaşu M.C., Elena Daniela Brăslaşu, Silvia Joiţa, M. Ghiţă, S. Ionescu, 2008 – Studies regarding the electrocardiogram in cattles in Dubois lead. Buletin USAMV, Veterinary Medicine, Cluj Napoca, 65, 2,  155 – 159.

4.     Brăslaşu Corneliu Mihail, Brăslaşu Elena Daniela, Irinel  Georgeta Verman, Ilinca Săvulescu Fiedler, 2004 - Cardiologie  Veterinară. Examinarea  aparatului  cardiovascular la  animale. Editura Artprint, Bucureşti.

5.     Lefcourt A.M., Erez B., Varner M.A., Barfield R., Tasch U., 1999 - A noninvasive radiotelemetry system to monitor heart rate for assessing stress responses of bovines.  J. Dairy Sci. 82, 6, 1179-1187.

6.     Meli F., Catarsine O., 1980 – Electrocardiographic study in calves with new derivation method. Annali  dela Facolta di Med. Vet. Messina, 17, 81 – 100.

7.     Mendez L.C.N., Camacho A.A., Alves A.L.G., Borges A.S., Souza R.C.A., Ferreira W.L., 2001 – Standard  electrocardiographic  values in  Holstein calves. Arquivo Brasileiro Med. Vet. E Zootecnia, 53, 6, 641 – 644.