Beneath the surface: Complete atrioventricular block combined with Wolff-Parkinson-White syndrome and sick sinus syndrome

The combination of Wolff–Parkinson–White (WPW) syndrome, sick sinus syndrome (SSS), and complete atrioventricular block (AVB) is seldom reported. We present a case of A 61-year-old male who was admitted with syncope and palpitations. His electrocardiogram showed a preexcited QRS pattern consistent with transient cardiac pauses. WPW syndrome with SSS syndrome was diagnosed. The electrophysiologic study demonstrated the preexcitation through the left accessory pathway, but after its blockages, completed atrioventricular block emerged. The patient ultimately required pacemaker implantation, followed by the ablation of the accessory pathway. AVB may be masked by ventricular preexcitation, and atrioventricular node function should be evaluated before ablation.