An electrocardiogram (ECG) is a simple and painless test used to measure the level of electrical activity and rhythm in your heart. Sensors are attached to the skin on the chest, arms and legs to detect the electrical signals produced by your heart each time it beats. ECG is used to quickly detect heart problems and monitor your heart’s health:

  • Check abnormalities, such as thickened heart muscle
  • Check your heart rhythm
  • Diagnose a heart attack
  • See if you have poor blood flow to your heart muscle

Before an ECG, you may need to have your hair shaved or skin cleaned so the electrodes stick on your body properly. Also, if you are wearing an underwire bra, you might be asked to take it off as it could affect the readings of the ECG.

Stress ECG

A stress test, also called an exercise stress test, shows how your heart works during physical activity

A stress test or exercise stress test can determine your risk of having heart disease. It assesses how your heart works during physical activity since exercise makes your heart pump harder and faster this test may reveal blood flow problems within the heart.

A doctor performs the test. The doctor will learn how much your heart can manage before an abnormal heart beat rhythm kicks in or blood flow to your heart muscle drops. During an exercise stress test you will be asked to walk on a treadmill. The level of exercise will become increasingly difficult. Your ECG, heart rate, and blood pressure will be tracked throughout to enable the doctor to assess and it lets your doctor know how your heart responds to being under stress.


Ten small sticky patches called electrodes are put on your arms, legs and chest. These are connected by wires to an ECG machine which picks up the electrical signals that make your heart beat. This electrical activity is recorded and printed onto paper.
The whole test takes a few minutes and is completely painless. You will need to lie still as moving can affect the results.
An ECG can help detect problems with your heart rate or heart rhythm. It can help doctors tell if you’re having a heart attack or if you’ve had a heart attack in the past. An ECG is usually one of the first heart tests you will have. It does have some limitations, so often you will have one or more other tests too. An abnormal ECG reading doesn’t always mean there is something wrong with your heart.