Clinical History
An 80-year-old man attended hospital with chest pain. He had a dual chamber pacemaker inserted 19 years before for complete heart block. On three occasions subsequently he had revisions of his pacemaker. A left-sided ventricular lead was previously cut and the proximal end was secured into the pacemaker pocket.
Imaging Findings
At the time of this admission he had a right-sided VVIR system in place and working normally. His chest X-ray (Fig 1) showed that the redundant ventricular lead was no longer secured proximally in the pacemaker pocket. D-Dimer was elevated and a CTPA was performed (Fig 2). This revealed that the redundant ventricular lead had become detached and had migrated down through the right ventricle and into the pulmonary artery. The distal end remained anchored and the proximal end was lodged in the right main pulmonary artery and associated with thrombus.
Discussion
Non-traumatic chest pain accounts for 2-3% of A&E visits [1, 2]. The immediate priority is to exclude life-threatening causes, especially acute coronary syndromes which are relatively common, and pulmonary embolism and aortic dissection which occur less frequently [2]. Pacemaker insertion is widely used in the treatment of bradyarrhythmias. The most common complications of pacemaker insertion are lead displacement and pacemaker infection [3]. Rarely a displaced lead may migrate beyond the ventricle and this may result in presentation to A&E with symptoms less obviously related to the pacemaker.
Pacemaker complications are well documented in the literature, either as case reports or case series. However, there is relatively little discussion of how these complications may present. In most cases, such as erosion and infection, the problem and its relationship with the pacemaker device is obvious. Similarly, if syncope occurs after pacemaker insertion then lead dislodgement or fracture will be suspected and confirmed by interrogating the device. If, however, a lead becomes dislodged in a patient who is not dependent on that lead, then syncope may not necessarily follow. Should the lead then migrate, the clinical presentation of pacemaker system failure may result from trauma caused by the lead tip.
In our case, the problem was caused by a redundant lead which had been left in place and secured with a suture which subsequently failed. The pacemaker continued to work normally. The distal attachment had dislodged and migrated past the ventricular attachment into the pulmonary artery where it triggered thrombus formation. The patient therefore presented with chest pain, which did not have the character of myocardial ischaemia or infarction. Pulmonary embolism was considered and CTPA revealed the diagnosis. He was treated with heparin and warfarin. The lead was not explanted and he has remained well on anticoagulation.
Complications of pacemaker implantation usually occur early [4] and linking symptoms and recent procedures is therefore straightforward. In a case series of ‘delayed’ complications [5] all patients presented with chest pain within 4 weeks of implantation. In the two cases described, one patient presented at 5 months, and the other at 2 years after the procedure. The message for clinicians attending any patient who has a pacemaker and presents with chest pain, is to consider the possibility that detachment or migration of the pacemaker lead may be the cause of the pain. Prompt diagnosis and treatment can be life-saving.
Differential Diagnosis List
Migration of the redundant pacemaker lead into the pulmonary artery.
Myocardial ischaemia
Pulmonary embolism
Final Diagnosis
Migration of the redundant pacemaker lead into the pulmonary artery.
