(a) One-month -old baby boy with mild pulmonary hypertension. Note the right axis deviation (dominant R wave in aVR) and the positive T wave in V1. (b) Close-up

(a) Ten-year-old male with severe primitive pulmonary hypertension (PPH) . Tall R waves in the right precordial leads and reciprocal deep S waves in the left precordial leads can be noticed. According to the Chou classification, this is type A of right ventricular hypertrophy (RVH) due to pressure overload. (b) Ten-year-old male with a large ASD and mild pulmonary hypertension. Note the right intraventricular conduction delay and the ST changes in right precordial leads. According to Chou, this is type B of RVH , due to volume overload. RVH type C is described in chronic lung disease: in this case there are no classic signs of RVH and a pattern like rS in V1–V2 and RS in V5–V6 can be found, due to right ventricle pressure overload, the shift of the heart and to the emphysematous lung

(a) Thirteen-year-old female who underwent surgery for diaphragmatic hernia at neonatal age. She was left with severe pulmonary hypertension on pharmacological treatment. (b) The severe RVH is indicated by the Q wave in V1, as well as by the high right precordial R wave (RVH type A)

Eisenmenger syndrome . (a) Ten-year-old female with unrepaired VSD (late diagnosis). A biventricular hypertrophy can be noted. (b) Seven-year-old male with unrepaired CAVC (late diagnosis). Note the left axis deviation. (c) Fifteen-year-old female with unrepaired CAVC (late diagnosis). Note the left axis deviation and the biventricular hypertrophy.