Twiddler’s syndrome in extravascular implantable cardioverter-defibrillator: a case report

Twiddler’s syndrome is caused by rotation of the pulse generator, which could lead to device malfunction. It has been reported in patients with transvenous and subcutaneous defibrillators but not in those with extravascular implantable cardioverter-defibrillators (EV-ICDs).

A 57-year-old man with an extraction for infected transvenous ICD (TV-ICD) underwent an EV-ICD for primary prevention. Device checks pre-discharge and at 6 weeks were unremarkable. However, 3 months post-implant, the patient experienced an inappropriate shock due to oversensing of noise. Chest X-ray revealed lead displacement, with the device rotated nearly 180° with the lead wrapped around it. Surgical revision confirmed lead coiling and torn fascia sutures, consistent with Twiddler’s syndrome.

This is the first reported case of Twiddler’s syndrome in a patient with an EV-ICD, presenting with inappropriate shock due to oversensing of noise. Clinicians should consider Twiddler’s syndrome as a potential cause of lead dislodgment and EV-ICD malfunction. Early recognition is crucial to enable timely intervention, restore device function, and prevent further complications.