How to Apply Leads for EKG

Updated May 10, 2017

An electrocardiogram (EKG or ECG) is a test which measures cardiac activity and provides a snapshot look at the electrical activity of your heart. EKGs are obtained by placing electrodes and leads on a patient's chest, which send electrical signals to the EKG machine. Proper EKG lead placement is essential for an accurate cardiac reading, and depends on whether a 3-lead, 5-lead or 12-lead EKG is being performed. The steps, however, are the same for each.

Remove your patient's shirt to bare the chest. A female patient will need to remove her bra; however, have her wear a gown with the opening in the front for modesty as well as accessibility to the chest.

Prepare the patient's skin by using alcohol pads to remove any oils, lotions or powders. Wipe over the clavicles, the sternum and around the left breast to the armpit. You may also cleanse a small area on both upper arms as well as the calves, about three inches above the ankle if performing a 12-lead EKG. Male patients who have copious amounts of chest hair may need to be shaved over the sternum and around the left breast to ensure the EKG pads adhere properly.

Determine what type of EKG you are to perform a 3-lead, 5-lead or 12-lead, and select the appropriate leads and number of electrode pads.

Place electrodes, adhesive side down, onto the patient. Most EKG machines come with diagram cards which show correct electrode placement for the type of EKG you are performing. Press each electrode firmly and make sure each is adhering well, without any gaps or lifting up from the skin.

Secure the EKG leads to the electrodes. Leads are colour-coded and contain abbreviations that indicate correct placement on the body, such as "RC" for right clavicle. Or, the EKG diagram may indicate where leads should be placed based on their colour for the type of EKG you are performing. Clip one lead to each electrode. Once all leads have been placed, the EKG machine will be able to read cardiac activity.


Be sure to apply leads correctly, or the EKG will not provide an accurate reading. If you must shave a man's chest in order to get electrodes to stick, wipe the areas of the chest to be shaved with several alcohol pads before shaving. This prevents burning associated with cleansing the skin after shaving. If you must remove an electrode from the skin while preparing the test, do not reuse it. Instead, replace it with a new electrode.

Things You'll Need

  • EKG machine
  • Electrodes
  • EKG leads
  • Razor
  • Alcohol pads
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About the Author

Elizabeth Otto has been writing professionally since 2003. She is a licensed emergency medical technician-intermediate with over 10 years of experience in the field. She has worked as a clinical assistant in family health and emergency medicine since 1995. Otto is a freelance writer for various websites and holds an Associate of Science in medical assisting from Commonwealth College.