Saturday, August 29, 2020


Hi friends!!!

In our previous blogs, we have discussed about MRI scanner. Please check out for the links below.

MRI scan 

MRI With Contrast

Brain MRI

Types of MRI scanners

In today's blog we are going to discuss about electrocardiogram.

The human heart is the most essential and valuable organ of our body. Electrocardiogram is used to diagnose the disorders in the functioning of heart. Therefore it is important for every healthcare professionals to know about electrocardiogram.


Let's get into the topic. 




The electrocardiogram is a painless procedure used to monitor and measure the electrical activity of the heart. The electrocardiogram is used to record the heart rhythm in a continuous moving sheet of paper or electronically displays it in a monitor. Heart irregularities and other cardiac problems can also be detected using electrocardiogram.

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The electrocardiogram is used to detect the time taken for electrical signal to pass through the heart and how much electrical signal passes through the heart.

The electrocardiogram is used to detect the abnormal heart rhythm (arrhythmia), blockages in the coronary arteries, enlargement of heart, damages in heart muscle and proper functioning of implantable devices like pacemakers. The abnormal amount of electrolytes like potassium and calcium can also be detected using electrocardiogram. The condition of heart after heart attack and heart surgery can also be detected using electrocardiogram.

The electrocardiogram is also used to evaluate the reasons for following problems.

1. Chest pain.

2. Breathing problem.

3. Tiredness.

4. Dizziness.



Our human cells communicate with each other using electrical signals. Likewise, each time when heat beats, the electrical signal travels through the heart. These electrical signals are sent by a group of cells into the right atrium of the heart called as sinoatrial node. These electrical signals spread around the heart and causes atria to contract first and then ventricle. The effects of these signal passage can also be seen on the skin surface, which can be measured using electrocardiogram.

In electrocardiogram procedure at least four electrodes are placed on the chest or four extremities of the patients. Generally, a set of colour codes are used for electrode placement. For right arm – white, left arm – black, right leg – green, left leg – red. Variations in this setup can also be made to have more flexible electrocardiogram procedure.

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These electrodes placed on the patient’s body tracks the electrical signal moving through the heart and records the timing and strength of the signal in a graph called P wave.

The ECG waveform has 3 patterns as following: P wave, QRS complex, T wave.

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Generally wet electrodes are used in ECG procedure which requires a adhesive to increase conductivity between electrode and skin surface.



During electrocardiogram patient’s will be asked to remove any objects from their body that may interfere the ECG recordings like watches, chains etc.

Patient’s will be instructed to remove the clothes from waist up and lie down flat on the bed. Meanwhile the technicians will ensure the privacy of the patient’s by covering the patient’s with bedsheets.

Patients will be instructed to remain still and silent during the procedure so as to not interrupt the ECG signal acquisition.

A gel will be applied on some specific areas of the patient’s body where the electrodes will be connected to improve the adhesiveness between electrode and the patient’s body.

The electrodes will be attached on patient’s legs, arms and chest. The lead wire will be connected to the electrodes.

Now I hope you have acquired some knowledge about electrocardiogram. We will discuss in detail about ECG leads placement, ECG waveform and interpretation, types of ECG machine in our future blogs.

NOTE: Dear friends!!!... Please do comment a topic related to Biomedical, so that we can discuss it in future blogs.

Check out for this blog about Computed Tomography and x ray.

Generations of CT Scanners


x ray machine working principle

components of x ray tube



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