Cardiomegaly and CHF do not occur in Fallot's tetrology. No CardiomegalyFirst you should know the following facts : -Pressure overload to ventricles causes concentric hypertrophy without dilatation. Volume overload to ventricles causes hypertrophy with dilatation → Eccentric hypertrophy.Due to pulmonary stenosis, there is pressure overload to right ventricle → Concentric hypertrophy of right ventricle without dilatation → No Cardiomegaly.No CHFThe VSD of TOF is always large enough to allow free exit to the right to left shunt. Since the right ventricle is effectively decompressed by the VSD, CHF never occurs in TOF.