Lead dislodgement, also known as twiddler syndrome, is a complication of implanted cardiac conduction devices due to patient manipulation of the pulse generator, typically diagnosed on plain chest radiograph.
A variation of this complication can also occur with implantable ports, deep brain stimulators, and other devices.
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Epidemiology
The incidence of lead dislodgement of cardiac conduction devices is relatively infrequent at 1-8% and there is a female predominance 1. It is also more prevalent in the elderly, in obese patients, and in patients with multiple cardiac leads 1.
Radiographic features
Plain radiograph
Lead dislodgement can be divided into various subtypes based on the appearance on plain radiograph 1. These mechanisms may occur independently or in combination.
fixation release type: simple dislodgement of one or more leads with no change in the position of the pulse generator; there is a lack of lead slack
twiddler type: due to rotation of the pulse generator in a craniocaudal direction; all leads retract and are twisted around each other
flip type: due to rotation of the pulse generator in a transverse direction; all leads retract and wrap around the generator
reel type: due to rotation of the pulse generator in a clockwise/counterclockwise direction; all leads retract and wrap around the generator in a coil-like fashion
ratchet type: (most common subtype) due to stepwise one-way retraction of the lead towards the pulse generator; one or more leads retract and accumulate within the subcutaneous pocket
Treatment and prognosis
Dislodgement of the leads renders the device non-functional and requires revision by the cardiologist. The consequences are life-threatening if left untreated.
History and etymology
"Pacemaker-twiddler's syndrome" was first described in 1968, referring to a case of permanent malfunction of a pacemaker due to the patient's manipulation ("twiddling") of the pulse generator 4,5.