Obtaining a pediatric ECG: beyond the standard 12-lead ECG

Most clinicians are familiar with the standard 12-lead ECG, but pediatric ECG acquisition routinely includes three additional leads. The 15-lead ECG can provide valuable information about cardiac position, anatomy, and electrical activity, supporting a more comprehensive cardiovascular assessment in children.

In this lesson from our Pediatrics ECG course, you'll learn how to:

• Differentiate a pediatric 15-lead ECG from a standard 12-lead ECG
• Position V3R, V4R, and V7 leads in preparation for pediatric ECG 
• Explain the role of right-sided ECG leads in identifying dextrocardia
• Describe the role of V7 in assessing the lateral wall of the left ventricle
• Recognize the value of a 15-lead ECG in the cardiovascular assessment in children

[0:00]
In another Medmastery lesson, we discussed the physiological differences between the pediatric and adult hearts, as well as the cardiopulmonary changes that occur in the pediatric patient. Now let's discuss the differences in preparing to perform an ECG on a child, as the process of collecting the ECG is also slightly different.

The standard 12-lead ECG

[0:22]
We are familiar with the conventional ECG used for adults, which consists of six limb leads, I, II, III, aVR, aVL, and aVF, and six precordial leads, V1 through V6, placed on the chest, for a total of 12 leads captured by 10 electrodes.

Pediatric ECG: using a 15-lead ECG

[0:41]
But the standard approach for obtaining an ECG in pediatric patients less than 18 years is to use 15 leads captured by placing an additional three electrodes on the chest. The three additional electrodes correspond to three leads, V3R, V4R, and V7.

Placement of V3R, V4R, and V7 leads

[1:02]
V3R and V4R are right-sided precordial leads that are placed on the right side of the chest, mirroring the positions of their counterpart leads, V3 and V4, which are located on the left side. V7 is placed in the fifth intercostal space along the left posterior axillary line, just to the left and behind V6.

Why right-sided ECG leads are used

[1:25]
These additional leads are meant to provide ECG information from the right side of the chest. But why would we need ECG information on the right side of the chest when the heart is located on the left side? Well, because the heart isn't always on the left side, known as levocardia. In some patients, the heart is located on the right side of the chest, or dextrocardia. Congenital conditions like this are often identified during childhood, where establishing a baseline can be helpful for future assessments and management. 

Detecting dextrocardia on ECG

[1:56]
Right-sided leads ensure a comprehensive assessment of the heart's electrical activity when it's positioned atypically. Though dextrocardia is uncommon, occurring in about one in every 12,000 patients, patients with congenital heart disease are much more likely to have dextrocardia. Placing leads on the right side of the heart makes it much easier to identify this variant on a conventional ECG.

How V7 improves cardiovascular assessment in children

[2:23]
The third additional ECG lead for pediatric patients is V7, recorded by an electrode placed on the left side. V7 provides information on the far left side of the heart, specifically the electrical activity on the lateral wall of the left ventricle, helping to identify electrical abnormalities that standard leads might miss.

The clinical value of V7 in pediatric ECG

[2:45]
This is particularly valuable in pediatric patients with unique or developing cardiac physiology, including those with congenital heart defects, suspected arrhythmias, or conditions such as right ventricular hypertrophy or ischemia. These additional leads provide a more comprehensive view, helping to detect subtle abnormalities in the posterior or lateral walls that might otherwise be overlooked.

When to use a 15-lead ECG in children

[3:11]
You may be wondering when it is appropriate to use a 15-lead ECG. As a pediatric electrophysiologist, I would say on every child requiring an ECG, as we cannot assume a patient will have normal left-sided heart positioning.

Benefits of using 15-Lead ECG in pediatrics

[3:26]
Acquiring a 15-lead ECG requires minimal additional time and can provide useful information in detecting right ventricular strain, congenital heart defects, or subtle ischemic changes in the pediatric setting.