Inappropriate implantable cardioverter defibrillator shocks due to atrial far-field on the tip-to-ring channel for lead dislodgement.

We reported a case of inappropriate implantable cardioverter defibrillator shocks, due to atrial far-field on the tip-to-ring channel of the fast electrical activity during atrial fibrillation, caused by lead dislocation in the right ventricle outflow tract. During these episodes the can-to-right ventricle coil signal correctly recorded the ventricular activity. The shock storm stopped when an antitachycardia pacing restored sinus rhythm.