ELECTROCARDIOGRAPHIC PARAMETERS IN NEW - BORN CALVES (172 CASES)

Banat's University of agricultural

sciences and veterinary medicine

"King michael i of romania"

from timisoara.

Lucr. Ştiintifice Med. Vet.
Vol. xlvii (4), 2014. p. 14-19.

Electrocardiographic parameters

in new - born calves (172 cases)

BRĂSLAŞU ELENA DANIELA, SILVIA JOIŢA, SIMIZ FL.*, BRĂSLAŞU M.C.

¹University of Agronomic Sciences and Veterinary Medicine of Bucharest, Faculty of Veterinary Medicine, Splaiul Independentei, no. 105, Bucharest, Romania, Post Code 050097, cbraslasu@yahoo.com

Banat’s University of Agricultural Science and Veterinary Medicine Timisoara, Faculty of Veterinary Medicine, 300645, Calea Aradului, no 119, Timisoara, Romania

Summary

172 new - born calves with ages between 1 hour-3-4 weeks have been investigated. The calves were clinically healthy. The examination was realized in standing position and the ECG parameters were: a milivolte amplitude of 10 mm, a rate of ECG tract rolling of 25 mm/sec, unipolar and bipolar legs derivations. The length of ECG component parts (sec): P wave = 0.05±0.013; P-R interval = 0.12±0.027; QRS complex = 0.047±0.012; QT interval = 0.250±0.051; T wave = 0.079±0.016; R-R interval = 0.525±0.015; P-T interval = 0.376±0.074; T-P segment = 0.147±0.1 and cardiac frequency electrocardiographically calculated based on R-R interval was 123.15±33.6. The amplitude of ECG waves in new born calves in D₂ derivation is: P wave=0.154±0.072 mV; ventricular complex = 0.910±0.485 mV; T wave = 0,410±0,244 mV. The values of electric axes are: P wave = 50.02±29.69°; ventricular complex = -95.77±38.67° and T wave= 77.42±30.28°.

Our conclusions were: estimation of ECG values in new born calves is very useful, considering the diverse pathology in this specie at this specific age: cardiomyopathies consecutive to a selenium deficiency, congenital heart malformations and others.

Key words: calves, new-born, electrocardiogram, standard leads.

Electrocardiography is a very important method for the diagnosis of cardiovascular diseases (6).  The study of electrocardiographic  parameters in this specie is useful as cardiovascular diseases (heart congenital defects, cardiomyopathy produced by tocopherol deficiency – selenic cardiomyopathy, pericarditis s.a.) also  influence  the calves (2).

Materials and methods

172  new born calves have been evaluated. They were healthy individuals, aged several hours to 14 days. Animals have been examined awake and in  standing position.

The examination has been done with an electrocardiograph  Nihon-Kohden – Cardiofax. The working parameters were: amplitude 1Mv = 10mm (5 and 20mm) and the speed of the rolling paper 25-50mm/sec.

Bipolar and unipolar limbs leads were  used.

The next statistical values  were estimated:

- arithmetic mean

- standard deviation

- variance

- error of the mean

- variability ratio (%)

Results and discussions

There are a few bibliographical data on characteristic electrocardiographic values in calves. These available data  show only the length of ECG components. There are only a few data available on values of ECG wave amplitude. This fact is due to the lack of a standard system of derivation, but also to a cardiac and non-cardiac pathology (electrolyte disturbances, lack of  acid base balance), which can influence the amplitude of ECG waves (1, 4).

All these factors can modify the amplitude of ECG waves, as there is a large variability of statistical values (variance and variability index)

The estimation of ECG parameters length has been done mainly in D2 lead, because in this lead the amplitude of the ECG wave is the highest and therefore can be easily examined.

The estimation of ECG waves amplitude has been realized in all 6 standard leads (3, 5).

As a first remark, calves electrocardiogram is included in B electrocardiographic group or the equine type: ventricular complex is in an opposite plan to P and T wave (figure 1)(3, 5).

Values of ECG waves amplitude in new born calves are included in tables   1-3.

Values of ECG components  length are included in table 4 and values of electric axis of ECG waves in table 5.

Figure 1

Electrocardiogram aspect in new born calves

Table 1

P wave amplitude values in new born calves

P wave amplitude mV
	n.	Arithmetic mean	Standard deviation	Variance	Variability ratio
D1	122	0.146	0.079	0.006	54.10
D2	148	0.154	0.072	0.005	46.75
D3	142	0.089	0.070	0.004	78.65
aVR	132	0.139	0.069	0.004	49.64
aVL	124	0.084	0.068	0.004	80.95
aVF	140	0.094	0.090	0.008	95.74

Table 2

Ventricular complex amplitude values in new born calves

Amplitude of ventricular complex mV
	n.	Arithmetic mean	Standard deviation	Variance	Variability ratio
D1	140	0.626	0.384	0.147	61.34
D2	157	0.910	0.485	0.901	53.29
D3	154	0.874	0.484	0.234	55.37
aVR	147	0.612	0.416	0.173	67.97
aVL	142	0.618	0.342	0.117	55.33
aVF	151	0.832	0.451	0.203	54.20

Table 3

T wave amplitude

T wave amplitude mV
	n.	Arithmetic mean	Standard deviation	Variance	Variability ratio
D1	126	0.225	0.196	0.038	87.11
D2	155	0.410	0.244	0.059	59.51
D3	147	0.327	0.227	0.051	69.41
aVR	141	0.270	0.184	0.034	68.14
aVL	133	0.204	0.157	0.024	76.96
aVF	148	0.339	0.204	0.041	60.17

Table 4

ECG components length (I.)

ECG components length (sec.)
	P	P-R	QRS	Q-T	T
n.	165	166	170	169	169
Arithmetic mean	0.05	0.12	0.047	0.25	0.079
Standard deviation	0.013	0.027	0.012	0.051	0.016
Variance	0.0001	0.0007	0.0001	0.002	0.0002
Variability ratio	26	22.5	25.53	20.4	20.25

ECG components length (II.)

	R-R	P-T	TP	F.C.
n.	167	164	164	167
Arithmetic mean	0.525	0.376	0.147	123.15
Standard deviation	0.150	0.074	0.100	33.607
Variance	0.022	0.005	0.010	1129.5
Variability ratio	28.57	19.68	68.02	27.28

Table 5

Value of electric axis (⁰)

Value of electric axis of ECG wave(0)
	n.	Arithmetic mean	Standard deviation	Variance	Variability ratio
P wave	145	50.02	29.69	882.04	59.35
QRS	143	- 95.77	38.67	1485.47	40.37
T wave	148	77.42	30.28	917.41	39.11

   Remarks on statistical data

A.      Amplitude of ECG wave

P wave is the representation of atrial electric activity and P wave amplitude is in most of the situations low. P waves had a monophasic aspect, on the same side with T wave.

Ventricular complex is on the opposite side to P and T waves (B electrocardiographic group) and the highest amplitude is seen in D2 lead.

As mentioned before, there are a lot of physiological and pathological factors (without any clinical signs) that modify the amplitude of ECG waves. As an example of phisiological factors there is the stress induced increase of ventricular contraction strength that can increase the amplitude of ventricular complex.

 There is also an evidence in this specie and at this age that a head deviation towards the left or the right side can cause significant changes of ECG waves amplitude in different leads. These are physiological changes as they are produced by compression of carotidian sinus.

All these factors are increasing the statistic index regarding variability and variability ratio

B.      The length of ECG components

The estimation of ECG components has a particular importance as the significance is as it follows:

P wave = atrial depolarisation

P-T = atrial systole

QRS = ventricular depolarization

Q-T = ventricular systole

R-R = length of a cardiac cycle, used to estimate cardiac frequency

TP = general diastole

P-T = general electric activity (atrial and ventricular systole)

Statistical index are homogenous, excepting TP segment, RR interval and cardiac frequency. The index above are influenced by different physiological and/or pathological factors (without clinical signs in these situations).

C.      Cardiac electric axis

Cardiac electric axis is positive for P and T wave and negative for ventricular complex. There is an increased variability of these index following the variability of ECG wave amplitude.

Conclusions

Electrocardiogram is one of the main methods to evaluate the heart in animal species. It is used to study arrhythmia, changes of cardiac cavities volume and indirect information of acid base imbalance or electrolytic imbalance.

New born calves electrocardiogram is included in B electrocardiographic group, with   a ventricular complex on an opposite side to P and T wave.

We used the next parameters: the milivolt amplitude =10 mm and the speed of rolling paper 25 or 50mm/sec. We used legs leads (derivations)

The length of ECG component parts (sec): P wave = 0.05±0.0001; P-R interval = 0.12±0.0007; QRS complex = 0.047±0.0001; QT interval = 0.250±0.002; T wave = 0.079±0.0002; R-R interval = 0.525±0.022; P-T interval = 0.376±0.005; T-P segment = 0.147±0.01 and cardiac frequency electrocardiographically calculated based on R-R interval was 123.15±1129.49.

The amplitude of ECG waves in new born calves in D₂ derivation is: P wave = 0.154±0.005 mV; ventricular complex = 0.910±0.235 mV; T wave = 0,410±0,059 mV.

The values of electric axes are: P wave = 50.02°; ventricular complex = -95.77° and T wave = 77.42°.

Our conclusions were: estimation of ECG values in new born calves is very useful, considering the diverse pathology in this specie at this specific age: cardiomyopathies consecutive to a selenium deficiency, congenital heart malformations and others.

References

1. Brăslaşu M.C., Cercetări electrocardiografice la viţeii nou - născuţi. Rev. Rom. Med. Vet., 2000, 10, 4, 401 – 405.

2. Brăslaşu Elena Daniela, Stavarache Anişoara, Popescu Al., L. Ioniţă, Dinu Cristina, Brăslaşu M.C., Roşu Petronela,  Standardizarea electrocardiografiei la bovinele adulte. Simpozion la 140 de ani Alma Mater Veterinaria Bucurescensis. Rev. Rezumate, 2001,  p. 98.

3. Brăslaşu M.C., Elena Daniela Brăslaşu, Iuliana Neagu, Silvia Joiţa, Huber M., Parametrii electrocardiografici la viţeii nou-născuţi. Rev. Rom. Med. Vet., 2004, 14, 3, 155 – 166.

4. Shekidef M.H.,  AL-Akraa A. M., M. M. Ghanem M.M., Studies on the effect of Medetomidine versus Romifidine in Buffalo calves. Assiut Vet. Med. J., 2007,  53, 291 – 309.

5. Brăslaşu M.C.- coordonator - Cardiologie veterinară. Examinarea aparatului cardiovascular la animale. Ediţia a II-a. Editura Artprint, Bucureşti, 2008.

6. Falcă Ctin., Mircean M., Moţ Th., Brăslaşu M.C., Giurgiu G., Vlăgioiu Ctin., Pop C., Papuc I., Solcan Gh., Vulpe V., Medicina internă a animalelor. Editura Eurostampa, Timişoara. Vol. 1., 2011.