Electrocardiogram (ECG)

What is an ECG?

An ECG is a graphical representation of the electrical activity of the heart. It is the most commonly performed cardiac examination. This is because it is quick and simple to perform and can be useful in screening for a number of cardiac conditions.

Why am I having an ECG?
  • To determine heart rate and rhythm
  • Evaluate electrical conduction
  • Previous heart attacks
  • Coronary artery disease
  • Abnormal electrolyte (blood salt) levels
  • Effects of drugs or devices (pacemakers) that regulate the heart
  • Prior to surgery
What are the risks involved with this test?

There are no significant risks associated with an ECG. Because the leads only detect electrical impulses emitted from the heart and do not emit electricity themselves so there is no risk of electrical shock.

Electrodes (stickers) that are attached to the body may cause a slight redness or mild discomfort when they are removed, similar to a band-aid.

What do I need to do to prepare for my test?
  • ┬áThe more relaxed you are during an ECG the better the result. Therefore, it is best to arrive a few minutes early so that you have time to relax before the beginning of the examination.
  • You do not need an appointment or referral
  • There are no restrictions on food or fluid intake prior to the test.
  • Please inform the scientist of any previous heart related conditions (eg. heart attacks, rhythm abnormalities, pacemaker, etc.).
  • You will be asked to remove all clothing from above the waist and may be asked to wear a hospital gown.
What happens?

You will be asked to lie face up on a bed. Electrodes (stickers) are then applied to your chest, arms and legs (see picture). This may require shaving of excessive chest hair or the rubbing of alcohol so that the electrodes remain attached throughout the test.

How long does the test take?

An ECG takes around 5 minutes to perform.