Lead fracture: a rare cause of symptomatic bradycardia in patient with permanent pacemaker

Introduction: Electrode fracture is a rare complication, but known in patients who have a permanent cardiac pacemaker or an implantable cardiac defibrillator. This complication occurs with an incidence which range from 0.1 to 4.2% of patients implanted per year, and the incidence progressively increases with implant time.

Methods: We present the case of a 60-year-old patient with VVIR single-chamber pacemaker type, implan-ted 2 years ago for complete atrioventricular block and atrial fibrillation, subsequently lost from our evidence, now, he comes for dizziness, fatigue and palpitations. The patient declares reappereance of the symptoms shortly after implantation, but has not provided the reasons for did not came for follow up of the device. Patient’s physical exam is significant for bradycardia, 36 bpm, with regular pulse, and signs of heart failure decompensation. The electrocardiogram shown total atrioventricular block with, approximate 40 / min junc-tional escape rhytm with atrial fibrillation and pacing failure failure; correct sensing, but the spike it is not followed by capture. The chest X-ray shows a partial interruption of ventricular electrode continuity at the subclavicular level. Interrogation of the pacemaker shown failure to pace and an impedance > 2500 ohms, thus confirming diagnosis of electrode fracture. The electrode impedance trend shows a sudden increase of impedance shortly after patient discharge, which coin-cides with the moment of reappearance of patient-related symptoms.

Results: We decide to insert a new ventricular lead and the old electrode was abandoned. Parameters obtai-ned with the new electrode were: sensing 15 mV, sti-mulation threshold: 0.8 V with 0.4 ms and impedance 637 ohms, being programmed VVIR 75-120 bpm. The patient’s symptom was almost completely resolved af-ter the introduction of standard heart failure treatment. The 1 month control reveal that patient’s device works appropriate, and the patient’s symptoms fully remitted. Conclusions: Symptomatology caused by electrode fracture may vary significantly depending largely on the degree of pacemaker dependence and include fa-tigue, dizziness, presyncope and syncope. The integrity of the electrode can be evaluated by measuring impedance which range from 200 to 1500 ohms. A sudden increase rather than a gradual increase of the impedan-ce value above the normal limit, associated with the pacing/sensing failure is a clear evidence of fracture. The fracture of the electrode can occur at the point of entry in the subclavian vein at the ligature and fixation site or at any point of excessive electrode angulation. In our patient, a new lead was implanted without compli-cations.

ISSN – online: 2734 – 6382
ISSN-L 1220-658X
ISSN – print: 1220-658X
The Romanian Journal of Cardiology is indexed by:
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CODE: 379
CME Credits: 10 (Romanian College of Physicians)