Latent complete atrioventricular block in a patient with Wolff–Parkinson–White syndrome and fast paroxysmal atrial fibrillation

The Wolf–Parkinson–White (WPW) syndrome is very rarely complicated with a complete atrioventricular block (AVB). In this case, the ventricle is activated entirely through the accessory pathway and the QRS complex is wide and exhibits maximum pre-excitation features. This case report describes a history of a 68 years old male with symptomatic WPW syndrome, episodes of rapid atrial fibrillation and complete atrioventricular block. Complete heart block in WPW syndrome should be suspected in the presence of a very wide, torn QRS, PJ interval > 0.27 s and paroxysmal atrial fibrillation without atrioventricular re-entrant tachycardia episodes.