Continuous ‘twiddling’ or manipulation of the pulse generator within its skin pocket, by the patient, leads to a painless dislodgment of device: subsequent coiling of the lead causes lead dislodgement, ultimately resulting pacemaker malfunction [1]. Variations of the phenomenon, leading to fatal device failure has also been reported with implantable cardioverter-defibrillators [2, 3] and cardiac resynchronisation therapy [3].
The pacemaker-twiddler’s syndrome has an estimated frequency of around 0.07–7 % [4–6]. The majority of cases are diagnosed within the first year of implant [2, 3], although it can occur at any time after device implantation. More recently a late Twiddler’s syndrome has also been described [7]. Our patient presented after 7 weeks of PPM implantation.
Manifestations of Twiddler’s syndrome vary, depending on the degree of entanglement, subsequent retraction of the electrode and final site of the dislodged lead. Leads that get dislodged further up may stimulate the ipsilateral phrenic nerves causing diaphragmatic contractions, occasional spasms of involuntary respiration or hiccups [1, 3, 4]. Further coiling and withdrawal of the lead, leads to stimulation of the brachial plexus, resulting in rhythmic arm twitching [1, 3, 4, 8]. Our patient did not experience these symptoms, as the retracted lead in our patient was confined to the right atrium.
The risk factors for the condition include female gender, obesity, elderly age group, impaired cognition and a smaller-sized implanted device relative to its pocket [4, 5, 9]. An associated increased laxity of the subcutaneous tissues, particularly in elderly patients facilitates further dislodgement of device [2, 3, 5]. Additionally, the smaller sizes of newer devices easily permit their rotation within the skin pocket [3.7].
The majority of patients with the syndrome deny manipulating the device [3, 4], although the syndrome encompasses deliberate manipulation as well [8, 9]. Our patient admitted to deliberate twiddling of the device, an unfortunate phenomenon which could possibly have been prevented with better patient education.
The chest X-ray is the simplest and most vital diagnostic tool to diagnose Twiddler’s syndrome [3], as it is rapid and gives a clear image of the lead coiling and device rotation. However, chest X-rays are frequently overlooked, and the focus is very often more directed at Holter monitoring. Admittedly, although Holter sheds light on the nature of the arrhythmia, the exact pinpointing of the cause of pacemaker failure in such cases, cannot be reached without X-ray imaging.
Treatment of diagnosed cases include uncoiling of the lead (done in our patient), implantation of a new lead and repositioning of the pulse generator [3, 8, 9]. As lax subcutaneous tissues permit device rotation, minimizing the pocket size, and suture fixation of the pulse generator with a ligature during implantation can prevent the occurrence of Twiddler’s syndrome [3–5, 7, 8].
A smaller and tightly fitting pocket without redundant space around the generator could also achieve better device fixation [5, 7]. Some authors advocate active fixation of the transvenous leads with non-absorbable suture [1, 4] or the use of a Dacron patch to promote tissue growth around the device and promote better fixation [1, 4, 10]. In their article, Fahraeus and Hoijer reserved the option of suturing the device to the fascia for patients with mental disorders, confusion and lax subcutaneous tissue [5].
Despite more stringent suturing procedures, proper patient education and counselling to care-givers, especially in elderly patients, remains the single most important means for avoiding PPM manipulations and preventing such fatal consequences [3].