Normalization of the QRS Complex by Concealed Conduction in a Patient with Wolff-Parkinson-White Syndrome

In a patient with Wolff-Parkinson-White syndrome, transient normalization of the QRS complex occurred as a result of retrograde concealed conduction into the accessory pathway from an A-V junctional escape beat. This patient also had a bradycardia-tachycardia syndrome.