An unusual source of electromagnetic interference.

A 62-year-old male presented to his treating cardiologist for routine interrogation of his implantable cardiac defibrillator on the background of severe ischemic cardiomyopathy and end-stage kidney disease on hemodialysis. The device log revealed multiple paroxysms of atrial fibrillation; however, upon scrutinizing these episodes it was evident that they always corresponded to episodes of hemodialysis while dialyzing through a chronic dialysis catheter, but not while dialyzing via an arteriovenous fistula. We report the novel finding of inappropriate sensing of current leak from the catheter by a lead with a floating atrial dipole.