Twiddler's syndrome: a rare cause of implantable cardioverter defibrillator malfunction

A 63-year-old female received an implantable cardioverter defibrillator having been resuscitated from an out-of-hospital (ventricular fibrillation) cardiac arrest. She had pre-existent diagnoses of left ventricular dysfunction (ejection fraction 15%) and aortic valve and root replacement surgery; coronary angiography revealed modest, non-flow-limiting coronary artery disease only. She sustained significant hypoxic brain injury which improved during her admission to the extent that she was able to provide written, informed consent prior to device implantation. A St Jude Durata dual-coil active fixation ventricular lead was implanted via the left subclavian vein, attached to a St Jude Ellipse VR pulse generator buried in a pre-pectoral pocket (chest X-ray—Panel A). ... At 4-week review, it was noted that the pacing threshold on the ventricular lead had risen from 0.4 V at implantation to 3.0 V. A repeat chest X-ray revealed rotation and downwards displacement of the generator together with marked twisting and torsion of the lead resulting in displacement of the tip of the ventricular lead hence the increase in threshold, consistent with the phenomenon known as Twiddler's syndrome (Panel B).