Twiddler's Syndrome: An Unusual Cause of Repeated Shocks by Implantable Cardioverter-Defibrillator in an Asymptomatic Patient

Abstract

Twiddler's syndrome refers to malfunction of pacemaker or implantable cardioverter-defibrillator (ICD) resulting from deliberate or unintentional twisting of pulse generator in device pocket, resulting in lead dislodgment. We report a case of a 65-year-old woman with multiple ICD shocks and antitachycardia pacing events on device interrogation, while she was unaware of the ICD discharges. Twiddler's syndrome is rare and mostly occurs in obese or elderly because of loose subcutaneous tissue allowing pulse generator to rotate in its pocket. It can be prevented by patient education against hand manipulating the generator. Smaller device pocket or suturing generator to fascia can also prevent future episodes.

Keywords: Implantable cardioverter-defibrillator (ICD); shock; twiddler's syndrome.

Figure 1

Electrogram from implantable cardioverter-defibrillator showing noise being interpreted as ventricular fibrillation

Figure 2

Electrogram from implantable cardioverter-defibrillator showing attempted antitachycardia pacing

Figure 3

Electrogram from implantable cardioverter-defibrillator showing implantable cardioverter defibrillator shock

Figure 4

Electrogram from implantable cardioverter-defibrillator showing attempt at postshock pacing

Figure 5

Chest X-ray from the time of initial implantable cardioverter-defibrillator implantation with correct lead position in right ventricle

Figure 6

Chest X-ray at the time of presentation with lead retracted into axillary vein and coiled around the generator while the generator itself flipped on its axis

Figure 7

Magnified image of Figure 6