This elderly patient presented 6months after a dual chamber pacemaker was implanted due to symptomatic chronotropic incompetence. They reported recurrence of exertional shortness of breath that was experienced before pacemaker implantation. Device interrogation revealed complete loss of capture in the atrial lead. The top Figure depicts lead orientation before (left) and after (right) patient twiddling resulted in loss of slack in both leads with frank atrial lead dislodgement. Arrows show the dislodged atrial lead and knotted leads. The bottom Figure shows the intraoperative finding of knotted leads in the pocket. The leads were carefully unknotted, stylets placed, and leads repositioned with normal parameters. Originally described in 1968 , twiddling refers to patient manipulation of pacemaker can or leads that may lead to malfunction. It has a reported incidence of 0.07% in a series of 17000 patients.  The patient underwent an uneventful lead revision by repositioning the atrial lead and adding slack to the ventricular lead.
1 Bayliss CE, Beanlands DS, Baird RJ, “The pacemaker-twiddler’s syndrome: a new complication of implantable transvenous pacemakers,” Can Med Assoc J, V. 99 (1968), pp. 371–3.
2 T. Fahraeus and C. J. Hoijer, “Early pacemaker twiddler syndrome,” Europace, Vol. 5 (July 2003), pp. 279-281.