ECG leads and recording ECGs in pediatric patients (children)
Principles of ECG leads, lead anatomy and electrical vectors have been discussed in the chapter The ECG Leads. Acquisition of ECGs in pediatric patients is slightly different from adults, due to obvious anatomical differences. There are, however, no differences regarding the ECG grid. As in adults, the x-axis represents time (the paper speed is typically 25 mm/s or 50 mm/s) and the y-axis represents amplitude (millivolts, mV). Please refer to Figure 1.
Figure 1. The ECG grid. The x-axis represents time and y-axis represents amplitude of the electrical signals generated in the myocardium. The same ECG grid is used in children and adult patients.
Recommendations for ECG recording in children
Pediatric patients frequently have difficulties being still during clinical examinations. The youngest children often display spontaneous movements of limbs, neck and trunk, which may cause disturbances and thus reduce the quality of the ECG recording. Moreover, the reason for recording an ECG may itself cause distress. Fortunately, most children (even the youngest) can be distracted by a parent or other personnel. Distracting the child during ECG recording may be recommended to reduce muscle disturbances. To further reduce muscle disturbances it can be advised to place the limb electrodes more proximally (closer to the trunk): leg electrodes are placed proximally on the thighs and arm electrodes are placed proximally on the upper arm.
Placement of chest (precordial) electrodes are not changed but additional leads may be attached in children under the age of 5 years. These additional leads are V3R, V4R and V7. V3R and V4R are used in children under the age of 5 years due to the fact that their right ventricle is located to the right of sternum. The anatomical location for V3R and V4R are identical to V3 and V4, but on the right side of the chest wall. Refer to Figure 2.
Figure 2. Placement of chest leads in children
Placement of chest electrodes (precordial leads) in children
- V1: placed in the fourth intercostal space, to the right of the sternal border.
- V2: placed in the fourth intercostal space, to the left of the sternal border.
- V3: placed diagonally between V2 and V4.
- V4: placed on the left medioclavicular line between rib 5 and 6.
- V5: placed on the anterior axillary line, on level with V4.
- V6: placed on level with V4 and V5, in the mid axillary line.
- V4R: placed on the right medioclavicular line between rib 5 and 6.
- V3R: placed diagonally between V2R and V4R.
- V7: placed on the back, directly inferior to scapula.