ECG obtained in a 3 year-old child with pulmonary hypertension. Findings include:
- Right atrial enlargement (arrow): The P wave in lead II is >2.5 mm. This is sometimes referred to as "P pulmonale."
- Right ventricular hypertrophy: Tall R waves in V1 and deep S waves in V5 and V6 suggest RVH. R wave amplitude in V1 is 30 mm (upper limit of normal for this age is 20 mm).
- Rightward axis deviation: QRS axis in this child is 125 (upper limit of normal for this age is 110).
