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Twiddler syndrome

Case contributed by Dr Eric F Greif


Patient states that his pacemaker/ICD started firing multiple times today. He denies any recent pacemaker revision.

Patient Data

Age: 55 years
Gender: Male

Triple lead left-sided pacemaker with evidence for migration of the leads. The left ventricular lead projects over the right ventricle and the other two leads overly the superior vena cava and left brachiocephalic vein. The proximal wires are curled upon themselves and adjacent to the pulse generator/battery pack.

Lungs demonstrate no pneumothorax, consolidation, vascular congestion, or pleural effusion. The cardiac silhouette is not enlarged. The osseous structures are intact.


With twiddler syndrome the leads become dislodged, as seen on this radiograph. The red arrow points to the left ventricular lead, which has migrated out of the coronary sinus and into the right ventricle. The blue arrow points to the right ventricular lead with has displaced into the mid SVC. The purple arrow points to the right atrial lead which has been pulled back into the left brachiocephalic vein. The black arrow points to the proximal coiled leads secondary to patient manipulating the pacemaker device.


On a prior chest radiograph of the same patient, notice that there is a correctly positioned left sided triple-lead biventricular pacemaker/ICD. One lead at the right atrium, one at the right ventricle and one lead at the left ventricle which goes through the coronary sinus.

No acute cardiopulmonary pathology.

Case Discussion

After much discussion with the ED physicians the patient admitted to "fooling around" with the pulse generator, not being aware that the leads could be dislodged.

A biventricular pacemaker usually has three leads: one is guided to the right ventricle, one to the left ventricle via the coronary sinus, and the third (variably present) is guided to the right atrium.

Twiddler syndrome refers to malfunction of a pacemaker due to the patient's manipulation of the pulse generator or wires. It begins with the patient's deliberate or subconscious spinning of the pacemaker's pulse generator in a spacious pocket. The leads are dislodged, and ventricular pacing ceases 1.

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Case information

rID: 38040
Published: 2nd Jul 2015
Last edited: 14th Aug 2019
System: Cardiac, Chest
Inclusion in quiz mode: Included

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