ABSTRACT
RV preferentially channeling through the VSD into the LV, rather than through the stenosed RVOT. The EKG typically shows patterns of RV hypertrophy and strain. Chest x ray reveals a classical ‘boot-shaped’ heart due to RA and RV enlargement with pulmonary oligemia. The subvalvular muscle of the RVOT can constrict as when the child gets upset, causing more right-to-left shunting, increasing cyanosis and thus causing a ‘blue spell’. Many children with TOF remain acyanotic beyond the first year of life, but then become progressively more cyanosed, whilst others with more severe early cyanosis may die prematurely.
