Tips for ECG recording in children
Limb electrodes may be placed more proximally on the limbs than the conventional distal placement. This will produce less movement artefacts in children who are less likely to stay quiet during the entire period of record. V3R and V4R should be recorded in addition to the standard 12 leads. Standard paper speed (25 mm/s) and gain (10 mm / mV) are used for paediatric recordings also. Half gain (5 mm / mV) recordings are done if the complexes are large. Recording can be done under sedation or during natural sleep or sometimes even by distraction techniques to keep the child quiet.
Indications for ECG in children
Chest pain is seldom of cardiac origin in children, even though an ECG is often obtained for chest pain in children as in adults. Important indications for ECG in children:
- Exertional symptoms
- Cyanotic episodes
- Heart failure
- Electrolyte disturbance
- Congenital or rheumatic heart disease
- Kawasaki disease
Evolution of ECG with age
Right ventricular dominance is the rule in ECG of neonates and is characterised by right axis deviation, tall R and T inversion in V1. Upright T waves in V1 abnormal after the first 72 hours of life.
Resting heart rate varies with the age, progressively decreasing as age increases: newborn: 140 / min; 1 year: 120 / min; 5 years: 100 / min; adult values being reached by about 10 years of age.
PR interval also progressively increases as age advances. At birth it is 80 – 160 ms; at 1 year : 70 – 150 ms; at 5 years : 80 – 160 ms and at 10 years: 90 – 170 ms.
Maturation of QRS axis in the frontal plane is earlier than in the horizontal plane – dominant R wave in lead I occurs by 6 months while the dominant S wave in V1 develops in all by 5 years.
ECG findings which may be normal in a child, though it may be abnormal in an adult
The following findings may be normal in a child, though it may be abnormal for an adult:
- Heart rate above 100 / min
- QRS Axis more than 90°
- Right precordial T wave inversion (also known as juvenile T wave inversion)
- Dominant right precordial R waves
- Short PR interval
- Short QT interval
- Short P wave duration
- Short QRS duration
- Inferior and lateral Q waves
Peculiarities of ECG of a preterm infant
ECG of a preterm infant can have:
- Lesser amplitude of QRS and T wave in limb leads
- Less RV dominance
- More leftward forces
- More leftward QRS axis
- Higher incidence of deep Q in V6