Pitfalls in electrogram interpretation: Subcutaneous cardioverter defibrillator malfunction in Brugada syndrome.

A patient with Brugada syndrome implanted with subcutaneous implantable cardioverter defibrillator (S-ICD) had oversensing episodes treated with S-ICD shocks. Comparable artifacts were not evocable with S-ICD pocket manipulation. The fluoroscopy excluded S-ICD macroscopic damage. The device extraction revealed undamaged pulse generator and connector, but the lead was inappropriately tunneled under the sixth rib. Then the S-ICD malfunction was due to lead microscopic damage caused by the lead rubbing the rib surface.