Learning Radiology xray montage

Twiddler's Syndrome

  • Rare occurrence
    • Shape and weight of pacemakers today
  • Subconscious, inadvertent or deliberate rotation of pacemaker in its subcutaneous pocket
  • Older women may be at particular risk
    • Loose subcutaneous tissue
  • Lead retracts and begins to wrap around the pacemaker itself
    • Dislodging lead from endocardium and causing
    • Malfunction of device
    • Pacemaker may begin to stimulate diaphragm, vagus or phrenic nerve, pectoral muscles or brachial plexus
  • Imaging findings
    • Chest x-ray shows looping of wires around pacer
    • Retraction and change in position of tip if wire or catheter
  • May result in sudden cardiac arrest due to conduction disturbances
  • Also occurs with automatic implantable cardiac defibrillators (AICDs)


 twiddler's syndrome

Twiddler's Syndrome: Frontal chest radiograph in top photo demonstrates pacemaker lead extending into right ventricle (blue arrows); bottom photo, one year later, shows wire lead is wound around pacer and tip of ventricular lead has retracted into the left subclavian vein (red circle)