Late Diagnosis of Residual Major Aortopulmonary Collateral in a Patient with Tetralogy of Fallot.

• Residual MAPCAs result in post-tricuspid shunt and PH. • Distinction between PH and conduit stenosis requires attention to TTE findings. • Management of complex adult CHD should be reserved for centers with expertise. • A multimodal imaging approach is often required to complete this understanding.