Electrocardiogram (ECG) is a non – invasive and harmless test used to assess the heart’s electrical activity. Contraction of the different regions of the heart to facilitate blood flow is maintained by the natural electrical impulses. These impulses are recorded as waves and intervals in the ECG. It gives information about the heart rhythm, the size and functioning of the heart chambers, and the heart rate.
An ECG abnormality could either indicate a variation of the heart’s rhythm or a medical emergency.
How is ECG performed? :
The patient is asked to remove the clothes covering his upper half and change into a gown. He will then be instructed to lie on his back on the examination table or bed for the test. The patient needs to lie entirely still throughout the procedure to avoid false results due to altered tracing. False results may arise due to interference by the impulses generated by the other muscles. The technician may shave or clip small patches of hair on the patient’s chest, arms, or legs if they are very hairy.
This action is performed if needed, provided the electrodes do not stick closely to the skin. Small, sticky electrodes are then attached to the patient’s chest, wrists, and ankles. These are connected to a machine by the lead wires. After this, the technician enters some information into the machine’s computer and starts the ECG. During this time, the machine converts the heart’s electrical signals into wavy lines. It is then printed on an ECG paper. Once the tracing is completed, the leads are disconnected, and the skin electrodes are removed.
Are there any risks involved in it? :
The entire procedure is safe and painless. While sticking the electrodes on the skin, the patient may feel a cooling sensation, but this is harmless. Some people may develop rashes or irritation to the patches, but this is very rare.
What are preparations required from the patient?
Fasting is not necessary before the test. The patient must notify the doctor about the medications taken by him. He must also inform the doctor if he has a pacemaker. It is generally advised to not drink cold water or exercise immediately before the ECG as these may give rise to false results. 
How long does it take?
An ECG generally gets over in about 5 to 10 minutes.
Who performs ECG?
It is generally done by a nurse or an electrocardiograph technician.
How much does it cost?
An ECG generally costs around Rs. 150 to Rs. 300.
When can I go home after the procedure?
The patient can resume his normal activities and return home immediately after the test.