The Electrocardiogram (ECG / EKG) Lab Test is suggested by the doctor when he wishes to study the heart and see if the person is suffering from any heart-related disease. A lab technician attached small electrode patches to the skin of the chest, arms and legs. These electrode patches help record the electrical activity of the heart.

The ECG test is very quick, safe and painless. This test helps the doctor in the diagnosis of the following –

• Diagnose a heart attack

• See if there is any improper blood flow to the heart (this is called ischemia)

• Check the rhythm of the heart

• Check on things that may be abnormal as far as the heart is concerned.

An ECG test doesn’t show if there are blockages in the heart nor can it predict a heart attack that can occur in the future. Additionally, it’s important to understand that there is a difference in the resting ECG and cardiac imaging test or exercise ECG or stress.

In case, there are no high-risk factors for heart diseases like high blood pressure or some other symptoms of heart disease; there is no need for this test as a part of the routine checks. Even then there are many people who have the ECG test conducted as part of the regular check-ups, which is not needed. Though the ECG doesn’t cause any harm, it might be a reason for unnecessary panic, due to an irregular heartbeat.

An electrocardiogram monitors and documents the electrical activity of the heart. It detects any issues with the heart's rhythm and is therefore utilized for the investigation and detection of heart disease like heart enlargement, heart inflammation and coronary heart disease.

ECGs from healthy hearts have a characteristic shape. Any irregularity observed changes the electrical activity of the heart and hence changes the shape of the ECG.

An ECG would probably be done, in case of high blood pressure or if any heart disease symptoms are displayed, like heavy or irregular heartbeats, chest pain or shortness of breath. A person may consider getting test done in case of occupational or screening requirements, or if there is a family history of diabetes, heart disease, or other ailments and the individual wants to begin exercising.

An ECG is ordered in certain conditions like:

• In persons displaying symptoms of a heart disease

• To check whether a patient has suffered a heart attack or evidence of a previous heart attack

• To monitor treatment for coronary artery disease

• To assess the function of artificial pacemakers

• To determine the size and position of the chambers of the heart

• Persons who may be at risk of heart disease due to:

• A family history of heart disease, Smoking habits

• Overweight

• Diabetes

• High cholesterol

• High blood pressure

When the heart function needs to be assessed, that’s where the ECG comes into the picture. If a person complains of chest pain or shortness of breath, the first thing a doctor would suggest is to get an ECG done. This would probably be the first test among the series of test which would help the doctor understand if there is an acute myocardial infarction or heart attack present. However, even if the heart attack is not determined in the test, it would still help the doctor understand whether there is narrowing in any of the blood vessels close/connected to the heart, known as atherosclerosis. It is a possibility that heart disease might not be picked up in the first ECG/EKG. It might involve a series of tests or some ECGs before the problem is diagnosed.

An ECG is ordered when a patient is experiencing symptoms such as:

• Chest pain

• Discomfort in other areas of the upper body

• Shortness of breath or difficulty in breathing

• Dizziness

• Fainting

• Irregular heartbeats

• Breaking out in a ‘Cold Sweat’

The patient might face some discomfort while the bandage or the patches are removed from the skin. Further, there might be some swelling or redness of the skin.

Preparatory instructions before the test :

Some medications like a few beta-blockers may interfere with the test results. Hence it is advised to check with the doctor before the test.

Also, avoid exercising or drinking cold water immediately before the ECG test since it may cause false results.

Avoid having a meal or having a caffeinated drink two hours before the test, as these can affect the rhythm of the heart.

Diagnostic procedure:

Small patches called electrodes are stuck to the skin in different areas of the body such as the arms, legs, and chest.

Typically, the chest area may be cleaned, i.e. some hair might be clipped or shaved to ensure that the patches stick to the skin easily.

Wires connect the patches to a machine that converts the electrical signals of the heart into wavy lines, which may be printed on paper to show a typical graphical pattern.

Usually, the ECG is taken while the patient is resting. However sometimes, while investigating the cause of heart disease, the ECG may be done when the patient is exercising or under minimal stress, to monitor changes in the heart. This type of ECG is often called a stress test.

The stress test may be done while the patient is on an exercise bike or treadmill. Immediately before the ECG test since it may cause false results.

Mostly, the doctors can explain the results of the test right after the test is conducted. Logically, if the results are normal, no further tests would be required. However, if the results show some problems with the heart, the patient might need to repeat the ECG test, or the doctor may even request for additional tests to be conducted, like an echocardiogram.

Most often, the ECG assessment includes the following:

• Heart rate determination,

• Assessing the rhythm of the heart,

• Evaluating the electrical conduction patterns. When the heart muscle is irritated, the way the electricity is conducted is very different than a normal heart muscle would behave. It's during ventricular contraction and recovery that the abnormal conduction may be apparent.