# ECG Recording

## Overview

This module describes how to record an electrocardiogram (ECG).

## Indications

1. Patients presenting with

   signs or symptoms of heart disease
   signs or symptoms of heart disease

   This may include chest pain, shortness of breath, palpitations, dizziness, syncope, or oedema.

2. Evaluating a patient’s cardiac function:

   1. Before a surgical procedure
   2. After an overdose, poisoning, drowning or electrocution
   3. After discovering tachycardia or bradycardia

3. Evaluating the effectiveness of therapy such as:

   1. Pacemakers
   2. Cardiac medication

## Contraindications

1. None

## Patient information and consent

Always verify your patient’s identity and obtain informed consent before proceeding.

### How do I explain this procedure?

“I am doing a test called an ECG. It is used to check the rhythm of your heart.”

### What can my patient expect?

“I will put a few stickers on your chest and attach wires from the machine. These wires monitor how your heart is beating. It is not painful, and the wires will not shock you.”

### What is my patient’s role?

“While I do the test, I need you to stay still and not talk, otherwise I’ll need to repeat the test.”

## Preparation

###

### Documentation

1. Patient notes

2. Patient labels

### Equipment

1. Alcohol-based hand rub

2. ECG machine (usually on a trolley with ECG leads attached)

3. ECG electrode stickers

4. Razor for shaving body hair if necessary

## Site & Positioning

Recline the patient at a 45° angle on a stretcher or bed. To minimise muscle tremor artefact, ensure that the patient is relaxed, comfortable and warm. Improperly grounded equipment in the room may also cause artefact.

Check whether the patient has a pacemaker in situ as this will explain the pacing mark on the ECG.

The ECG leads usually have a colour-coded diagram attached to show where to place each lead.

### Precordial leads

### Limb leads

## Procedure

Follow medical asepsis without gloves.

1. Perform hand hygiene.

2. Switch on the ECG machine.

3. Set the ECG paper speed at 25 mm per second.

4. Set the calibration or standardisation, to ensure that 10mm equals 1mV so that you can convert wave height into a meaningful voltage.

5. If the patient has excessive body hair, shave the areas of electrode attachment.

6. Stick the electrodes on the patient according to the diagram.

7. Attach the correct ECG lead to each sticker.

8. Check that the ECG machine shows a good reading for each lead on the screen. There should be no flat lines, which indicates that the corresponding electrode is not securely attached, or the lead is malfunctioning. Check for

   interference
   interference

   appears as irregular, sometimes broad ECG markings or "artefact". Press the interference button on the machine once to check for improvement.

   and if present, press the interference button on the machine once to check for improvement.

9. Remind the patient to remain still. Press the button to print the ECG, which differs on each device, but is usually easy to find.

10. Tear off the printed ECG and check that it has recorded accurately and includes all 12 leads, with no sudden jumps in the lines, and no flat lines. You may want to print a second copy if the patient is going to be transferred to another facility.

11. Switch off the ECG machine.

12. Detach the ECG leads and remove the electrode stickers.

13. Attach a patient sticker to the ECG and write down your name and the date and time of recording. Number the ECG if you plan to do serial ECGs.

14. When you have non-disposable electrodes, keep them clean and free of corrosion through regular maintenance.

## Troubleshooting

My patient has excessive breast tissue or breast implants.

When you reach the breast tissue, it is best to lift it up and stick the electrodes to the chest under the breast. Sticking over the breast can interfere with readings.

My patient is very sweaty.

Wipe the patient’s sweat down with a dry paper towel and stick on the electrodes immediately.

My patient has body hair and I can’t find a razor.

If absolutely necessary, you can use an ECG electrode sticker to “wax” body hair off a patient’s chest. As this is very painful, try to find a razor first.

The ECG has come out with jagged, irregular lines.

Patient movement may cause artefact. Try to encourage the patient to lie still.

There is one area of flat line on the ECG.

One of the leads may have gotten detached while you recorded, or that lead is broken.

The tracings are indistinct.

Check that there is sufficient ink or if the stylus has malfunctioned.

## Risks

1. Allergy or skin reactions to the electrode stickers

2. Skin damage when removing electrode stickers roughly

## References

1. Menzies-Gow E. How to record a 12-lead electrocardiogram. Nurs Stand. 2018;33(2):38-42. doi:10.7748/ns.2018.e11066

2. Hill P. How to record an electrocardiogram. In: Mash B, Blitz-Lindeque J, eds. South African Family Practice Manual. 2nd ed. Pretoria: Van Schaik Publishers; 2010:66-67.