Commentary: An Unusual Case of Leadless Pacemaker Implantation in a Patient with Wolff–Parkinson-White Syndrome: Just Because We Can, Does That Mean That We Should?

In the case presented by Drs. Tanaka-Esposito and Cantillon, a patient deemed to be at risk of developing unpredictable atrioventricular (AV) block based on electrophysiology findings and a catheter ablation procedure is chosen for the implantation of a leadless pacemaker that will provide permanent, prophylactic ventricular pacing. Briefly, this case involved a patient with a midseptal accessory pathway (AP) who had undergone a prior catheter ablation procedure for Wolff–Parkinson–White syndrome (WPW) 2 decades earlier. During the current procedure, anterograde AV conduction was seen over the accessory pathway with moderate (but not excessively rapid) conduction properties. A short application of low-energy radiofrequency (RF) current delivered in the midseptum transiently eliminated both pre-excitation and AV conduction. The authors concluded from these unexpected observations that anterograde AV nodal-His-Purkinje conduction was markedly impaired (perhaps even absent), possibly due to permanent injury to the compact AV node incurred during the previous ablation procedure. This challenging and unusual case raises several questions that may have implications for clinical practice, including whether septal AP ablation remains a highrisk procedure; when to ablate or not ablate these APs; what is the natural history of unablated accessory pathways; and whether prophylactic pacemaker implantation was warranted in this case and, if so, what strategy would best provide the needed protection from symptomatic bradycardia