Which one of the following congenital hea diseases has cyanosis without cardiomeglay and/ or congestive hea failure -

Ans. is 'b' i.e., Fallot's Tetralogy Cardiomegaly and CHF do not occur in Fallot's tetrology. No Cardiomegaly o First you should know the following facts : ? i) Pressure overload to ventricles causes concentric hyperophy without dilatation. ii) Volume overload to ventricles causes hyperophy with dilatation --> Eccentric hyperophy. o Due to pulmonary stenosis, there is pressure overload to right ventricle --> Concentric hyperophy of right ventricle without dilatation - No Cardiomegaly. No CHF o The 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.