What is the correct placement for electrocardiogram (ECG) leads?

From the Guidelines

The correct placement for electrocardiogram (ECG) leads involves specific anatomical positions for both limb and chest leads, as outlined in the American Heart Association's recommendations 1. For limb leads, the recommended placement is on the arms and legs distal to the shoulders and hips, but not necessarily on the wrists and ankles.

• The RA (right arm) electrode should be placed below the right clavicle.
• The LA (left arm) electrode should be placed below the left clavicle.
• The RL (right leg) electrode should be placed below the right ribcage.
• The LL (left leg) electrode should be placed below the left ribcage. For chest leads, the correct placement is:
• V1 at the fourth intercostal space at the right sternal border.
• V2 at the fourth intercostal space at the left sternal border.
• V3 midway between V2 and V4.
• V4 at the fifth intercostal space in the midclavicular line.
• V5 in the horizontal plane of V4 at the anterior axillary line.
• V6 in the horizontal plane of V4 at the midaxillary line. Proper lead placement is crucial for accurate ECG interpretation, as incorrect positioning can mimic pathological conditions like myocardial infarction or lead to misdiagnosis, as noted in studies 1. When placing leads, ensure the skin is clean and dry, and consider shaving areas with excessive hair to improve electrode contact, as recommended by the American Heart Association 1. Proper lead placement allows for the accurate recording of electrical activity from different perspectives of the heart, providing comprehensive information about cardiac function and potential abnormalities. It's also important to note that alternative lead placements, such as the Mason-Likar lead position, can be used in certain situations, such as ambulatory and exercise electrocardiography, to reduce noise and improve the quality of the recorded ECG 1.

From the Research

ECG Lead Placement

The correct placement of electrocardiogram (ECG) leads is essential for accurate and reliable interpretation of the ECG trace. The following are key points to consider:

• The 12-lead ECG records the electrical activity of the heart from 12 different viewpoints or 'leads' by attaching ten cables to the patient's limbs and chest 2.
• Correct positioning of the electrodes using anatomical landmarks is essential to ensure an accurate and high-quality ECG recording 3.
• The procedure for recording a standard 12-lead ECG includes preparation of the patient and of the equipment, and guidance is given on how to accurately locate the intercostal spaces to ensure correct positioning of the chest leads (V1-V6) 2.
• Skin preparation is essential, as suboptimal electrode contact or electrodes being placed where there is a significant amount of dry or dead skin cells, grease, sweat or hair, can negatively affect the quality of the ECG recording 3.

Challenges in ECG Lead Placement

There are certain challenges in ECG lead placement, including:

• In patients with burns to the chest, accurate lead placement may be compromised or impossible, and modification of the standard approach may be required 4.
• Numerous modified ECG lead configurations are used for continuous patient monitoring, and they often produce waveforms substantially different from the standard 12-lead ECG, which can lead to misdiagnosis and inappropriate therapy 5.

Importance of Standardization

Standardization of the procedure for recording a 12-lead ECG is important to achieve comparable results 2.

• An assessment tool has been proposed to compare the clinical utility of various lead configurations, which weighs factors such as equivalency to the standard ECG, patient comfort, noise immunity, noninterference with clinical interventions, and identifiable anatomical landmarks for accurate electrode placement 5.