An electrocardiogram is a test used to register the heart´s rate, rhythm and electrical signals over a period using electrodes at each moment through the cardiac cycle. Different voltages are made of depolarising and repolarising during each heartbeat.
HOW TO TAKE AN ELECTROCARDIOGRAM?
To take an electrocardiogram in veterinary the animal has to be in lateral decubitus or on its feet.
The first step is clean and sanitises with an alcoholic solution where the electrodes will be placed.
Next step is locating the electrodes on the necessary points for every lead. eKuore digital ECG makes possible to take one lead at the same time. If you need more than one lead, you can obtain three leads changing the position of the electrodes.
HOW TO TAKE LEAD II
To take a lead II with eKuore digital ECG first of all we will put some contact gel or spray to improve the conductivity of the patient skin and gets more precise results.
Next, we´ll find zone without hair or a little quantity of hair on the right armpit and we place the positive electrode there and the negative electrode on the left back leg. This position will allow to trace a lead II and pick up the electronic activity that is produced by the right atrium to the left ventricle. That´s an axis that goes through the heart.
HOW TO TAKE LEAD III
Same way is possible to obtain the lead I and the lead III. This location will get us similar information than the lead II when there´s not possible to receive the lead II for any reason (for an injury, abscess or any other problem).
To obtain the lead III starting from lead II, we should move the negative electrode to the right back leg. This way, we will receive the lead III
HOW TO TAKE LEAD I:
Finally, we can obtain lead I, if we change one more time the negative electrode to the left upper leg of the patient getting the lead I.
We´ll see that the electrodes are correctly located, and we will start monitoring with the eKuore digital ECG.
The three of them will give us similar information, and it is possible to use all of them dependent on which of them is more comfortable.
In ambulatory ECG on the consultation, frequently lead II is the standard, but sometimes on the operating room or emergencies can be better set the back part free or the left and change the electrode.
Is important being rigorous positioning the electrodes to get a correct electrocardiogram.
HOW TO READ AN ELECTROCARDIOGRAM
When we knew that the electrocardiogram was done correctly, we can start to read it. First of all, we are going to see the different intervals and waves that we find in an electrocardiogram.
P is the atrial systole contraction pulse
Q is a downward deflection immediately preceding the ventricular contraction
R is the peak of the ventricular contraction
S is the downward deflection immediately after the ventricular contraction
T is the recovery of the ventricles
1. HEART RATE
First of all is to get the heart rate. eKuore digital ECG doesn´t need to calculate the heart rate manually because it´s made automatically by the APP for ANDROID devices. This is a very useful tool and will help a lot to be used as a monitor.
2. HEART RHYTHM
In the second place, you should discover the heart rhythm. To know it, you have to observe if RR intervals are similar and if every cardiac cycle has a P wave before a QRS complex.
In normal resting hearts is produced the prototypical pattern of P wave, QRS complex, and T wave. It´s called Normal Sinus Rhythm.
3. PR INTERVAL
It is essential to determinate the distance between the beginning of the wave P and the start of the complex QRS. It has to be between 0.12 and 0.20 seconds; if not, there´s an abnormal electrocardiogram.
4. QT INTERVAL
We came back to the beginning of QRS and we measure till the end of wave T, excluding wave U.This interval is very important the heart rate and the value have to be corrected according to the heart rate. When the interval QT is adjusted, it has to be between 350 and 440 ms.
5. HEART AXIS
In this case, we will use the limb leads. It is the most complicated step and we recommend checking it with a specialist. This is very easy with the eKuore digital ECG because you can send the electrocardiogram immediately by email or apps that allows data exchange.
6. ST SEGMENT ABNORMALITIES
This segment is located between the end of complex QRS and the beginning of wave T. It has to be isoelectric, and it has to be compared with PR interval.
7. CHECK ALL WAVES AND INTERVALS
To end our analysis, we have to check every ECG wave and interval (P, Q and T)
This article is a little summary that explains in a simplified way how to read an electrocardiogram. The best option is always to consult with a specialist in cardiology. eKuore helps you to send the electrocardiogram immediately via email, WhatsApp and other Apps that allows data exchange.