How to Monitor an Animal's ECG

29/06/2022

Every contraction of a healthy heart is triggered by an electrical impulse, which originates from the sinoatrial node. The changes in electrical activity can be captured on the surface of the animal and recorded on the time axis, forming a repeating pattern. , a morphologically similar pattern of cardiac electrical activity, known as an electrocardiogram.




Significance of monitoring ECG
An abnormal ECG indicates possible underlying primary or secondary cardiovascular disease, and is helpful for the implementation of surgery and assisting physicians in diagnosis.
On the other hand, the ECG of animals with severe heart disease may also be normal (from "Small Animal Cardiology" - De-Ralf Tobias), so relying on the ECG alone is not enough, and must be monitored in combination with other parameters.


Accessories for ECG Monitoring



ECG monitoring steps
1. When the electrocardiogram needs to be recorded: the animal is placed in the right lateral position, and the animal is placed on the right side of the trunk after the forelimb is stretched. Wrong posture will cause the QRS complex and the ECG vector to change.
When only arrhythmia or heart rate needs to be monitored: Doctors can choose other suitable positions.

Skin Treatment:
Remove body hair from where the electrodes are placed.
Gently rub the skin where the electrodes are placed to remove dead skin cells
Wash skin thoroughly with soapy water or medical alcohol (ether and pure alcohol should not be used as this increases skin resistance).
2. Wet the animal skin and attach the ECG clip.
3. Place the electrode on the corresponding part of the animal.
4. Connect the lead wire to the main ECG cable, and then connect the main cable to the ECG interface on the monitor side.

Placement:
five guides
White Upper Right (RA) (Right Arm): Placed on the right upper limb.
Black Upper Left (LA) (Left Arm): Placed on the left upper limb.
Green Lower Right (RL) (Right Leg): Placed on the right lower limb.
Red Lower Left (LL) (Left Leg) : Placed on the lower left extremity.
Brown Chest (V) : It is placed on the chest wall, close to the heart on the left.



Placement:
three guides
White upper right (RA) (Right Arm): placed on the right upper limb.
Black Upper Left (LA) (Left Arm): Placed on the left upper limb.
Red Lower Left (LL) (Left Leg) : Placed on the lower left extremity.



Factors affecting the quality of ECG signals:
1. Breathing: Breathing action can cause changes in the position of the heart, changes in the electrical conductivity of lung tissue, and changes in ventricular congestion;
2. Age, gender, body type: if the heart rate of puppies is faster than that of adult dogs, the duration and interval of each wave will change;
3. Sedation and anesthesia;
Human factors and others:
Inaccurate electrode position; poor electrode contact; improper operation of the monitor, etc. During the measurement, the animal must be placed on an insulating surface, and the metal collar and iron chain of the animal must be removed.