How to connect ECG leads

The heart produces electrical activity that stimulates the pulsing necessary to propel blood through the body. To view the health of the heart and ensure these electrical impulses continue to work as desired, physicians and medical professionals administer ECG testing. An ECG, EKG or electrocardiogram measures and records the heart's electrical activity in the form of a line graph. Several different types of ECG testing exist, including the commonly used 12-lead ECG that produces 12 line graphs of the heart's electrical activity using only 10 wires and electrodes placed on the body.

Prepare electrode attachment sites by shaving away any hair on the electrode sites, wiping the area with alcohol swabs to remove lotions and body powders and drying the areas with a square of gauze. You will place one on each shin, one on each wrist and six across the chest, between both breasts and under the patient's left breast.

Make small marks with a washable marker to mark where to place the centre of each electrode. Start with the wrists and have the patient lie on their back with inner wrists and palms facing upwards. Use two fingers to locate the flattest part of the wrist and draw a small mark in this location on each wrist.

Locate a flat area on the shin, closer to the ankle than the knee. Draw a small mark on each shin in this location to mark where to place the electrodes on the legs.

Locate two flat areas on the interior side of each breast, along the edges of the sternum bone that lies between the two rib cages. Try to place the marks for the electrode on the flat space between the breasts and not on the breasts, as the fat in the breasts reduce conductivity and produce static on the ECG graph. Place the marks between the fourth and fifth ribs, counting down from the top.

Move down and to your right an inch or two and place a mark on a flat area below the breast and directly over the fifth rib down. Move down and to the right another inch or two and place another mark halfway between the fifth and sixth ribs. Move straight over one to two inches and place another mark between the fifth and sixth ribs. Move down and to the right again by another inch or two and place a final mark between the sixth and seventh ribs on the left side of the patient's body.

Peel the backing off ten electrodes and place the metal piece directly over each mark you made in the previous steps. Firmly press the electrodes down to adhere the sticky backing to the patient's skin.

Connect the ECG lead wires to the electrodes. The ends of the lead wires will snap onto the electrode nubs when you apply a bit of pressure. Read the small lettering on the ECG lead heads to determine to which electrodes the leads should attach. RA should attach to the right arm, LA to the left arm, RL to the right leg and LL to the left leg. V1 through V6 will attach to the chest starting at leftmost electrode and moving to the far-right on the patient's side.


Advise patients receiving ECG testing to avoid using body lotions and powders on the day of ECG testing so the electrodes will better adhere to the skin.

Things You'll Need

  • Razor
  • Alcohol swabs
  • Gauze
  • Washable marker
  • Electrodes
  • ECG machine
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About the Author

Penny Porter is a full-time professional writer and a contributor to "Kraze" magazine. She is pursuing a bachelor's degree in journalism at Eastern Kentucky University in Richmond, Kentucky.