Electrodes

Electrodes for electrocardiograms

An electrode is an electrical conductor that captures or releases a single electric current to analyse the activity of the heart in several ways.

The reusable or disposable electrodes are commonly used for resting or short-term ECG and are usually sold by the case or bag. 

What is the role of ECG/EKG electrodes ?

During ECG exams, the general practitioner or cardiologist uses ECG electrodes. The test is very quick and can be carried out in the office, in a hospital or on an outpatient basis.

ECG electrodes transfer electronic signals from the heart to the electrocardiograph. They are placed on the patient and connect the heart to the device. An optimal placement on the patient's body allows for a reliable recording. The placement of the electrodes is painless and safe.

What are the types of electrodes ?

A wide range of electrodes is available on the market, depending on the recordings to be carried out (long or short), it will be necessary to choose the appropriate models of electrodes for the best success of the ECG examination.

Some electrodes are reusable while others are single-use, without forgetting that some ECG electrodes can be gelled beforehand.

Sold in packs or bags, single-use ECG electrodes are often preferred to reusable electrodes as they are disposable and therefore reduce the risk of infection. They can be divided into four main categories :

• Snap electrodes :

This is the classic type of electrode. They have a metal connector that will be used to connect them to the patient cables: it can be in a central or remote position. In some models, they can also be used with electro-stimulation systems to strengthen or rehabilitate muscles.

• Tab electrodes :

Practical and repositionable as required, this type of electrode is suitable even in case of significant hairiness. They can be connected to the patient cable via crocodile clip adapters, if the patient cable requires it.

• Electrodes with jampers :

Used for stress testing ECG, among other things, electrodes with jampers are adapted for patient cables with banana plugs.

• Pre-wired electrodes :

These electrodes are designed for infants, neonates and young children. They eliminate pressure points and false alarms caused by lead disconnections. They do not require adapters and the integrated lead wires provide a safe and durable system.

Cardio Depot also offers a wide range of electrodes depending on the type of use : 

• Resting ECG electrodes :

These are electrodes suitable for short tests (between 5 and 10 minutes for an ECG).

• Electrodes for stress ECG :

Electrodes with jampers are used in particular for stress tests, and in all cases require a high adhesive power. 

• Electrodes for Holter :

Long-term electrodes are also used for Holter ECG. 

How to place the ECG electrodes on patient ?

It is crucial to place the electrodes correctly for an accurate and reliable ECG. The standard used since 1938, defined by Franck Wilson, must be applied and requires that the ECG electrodes be divided into two parts: 

- 6 ECG electrodes should be placed on the chest.

- 4 ECG electrodes are placed on the limbs.

• Electrodes placed on the chest :

V1 electrodes : the red electrode marked V1 will be placed in the right intercostal space in relation to the sternum (between the fourth and fifth rib).

V2 electrodes : In contrast to V1, the yellow electrode marked V1 will be placed in the left intercostal space in relation to the sternum (also between the fourth and fifth rib).

V3 electrode : green electrode should be placed between V2 and V3 accessories on the fifth rib.

Electrode V4 : brown electrode, to be placed on the left between the fifth and sixth ribs.

V5 electrode : this black electrode will be placed between V4 and V6.

V6 electrode : the purple electrode will be aligned horizontally with V4 and V5.

• Electrodes placed on the limbs :

These electrodes are made for the hands and feet. The red R (Right) electrode will be placed on the inner level of the right wrist while the yellow L (Left) electrode will be for the inner part of the left wrist.

The black N (Neutral) and green F (Foot) electrodes will be placed on the right and left ankle respectively.