The trapped endocardial electrode. Removal by prolonged graded skin traction

Cardiac device infections: getting to the heart of the matter

PURPOSE OF REVIEW

Use of electrophysiologic devices (permanent cardiac pacemaker and implantable cardioverter/defibrillator) has been increasing. Infection of these cardiac devices is a devastating complication, and medical treatment alone without device removal is often unsuccessful and frequently leads to infection relapse. This article reviews recent publications that address the diagnosis and management of infected electrophysiologic devices.

RECENT FINDINGS

Recent studies have shed new light on the incidence, risk factors, management, and outcome of cardiac device infection. Rates of both cardiac device implantation and infection have been increasing, although the rate of increase of cardiac device infection has outdistanced that of implantation and this has had enormous economic and clinical consequences.

SUMMARY

The large majority of cardiac device infections are likely due to pocket site contamination at the time of device placement. Hematogenous seeding from a distant focus of infection, particularly due to Staphylococcus aureus, can account for late-onset infection. Although no prospective studies have been conducted to date, management with parenteral antibiotics and complete device removal is the current standard of care. Further study is needed to better define optimal diagnostic and management interventions, particularly in patients with bloodstream infection and no local chest wall or echocardiographic evidence of cardiac device infection.

Myocardial Rupture After Pulling Out a Tined Atrial Electrode with Continuous Traction

Transvenous traction for the removal of retained pacemaker electrodes is common practice with few reported complications. This case reports a patient with a DDD pacemaker with extruded electrodes, who died of a myocardial rupture at the atrial lead site after prolonged (i.e., after 24 hours) traction was applied.

Permanent transvenous pacemaker implantation in forty dogs

Permanent transvenous cardiac pacemakers were implanted in 40 dogs. Electrocardiographic diagnoses included persistent atrial standstill (3 dogs), sick sinus syndrome (8 dogs), and high-grade second-degree or third-degree atrioventricular (AV) block (29 dogs). Thirteen dogs were alive and well 4 to 42 months after pacemaker implantation (mean, 16.9 months). The mean and median survival times of the 26 dogs that died or were euthanatized during the study were 17.9 months and 13 months, respectively. Most of these dogs succumbed to problems unrelated to the arrhythmia and pacemaker implant. One dog was lost to follow-up. Complications associated with permanent transvenous pacemaker implantation included lead dislodgement, infection, hematoma formation, skeletal muscle stimulation, ventricular arrhythmia, migration of the pulse generator, and skin erosion. Lead dislodgement was the most common complication, occurring in 7 of 9 dogs paced using untined electrode leads and in 6 of 30 dogs paced using tined leads. Lead dislodgement did not occur in the only dog paced using an actively fixed endocardial lead. It was concluded that permanent transvenous cardiac pacing is a feasible, less traumatic alternative to epimyocardial pacing in dogs, but that successful use of this technique requires careful implantation technique and anticipation of the potential complications.

Extraction of implanted transvenous pacing leads: a review of a persistent clinical problem

Within a few months of implantation, permanent pacemaker leads become ensheathed in fibrocollagenous tissue. This tissue may anchor the lead so that it is difficult, dangerous, or impossible to remove it. Leads with bulbous or finned tips are particularly resistant to extraction. The risks of applying traction to an entrapped lead include induction of bradycardia or ventricular tachycardia and fibrillation, invagination of the right ventricle, avulsion of the right ventricular myocardium or tricuspid valve, hemopericardium, and cardiac tamponade. Forceful traction may result in uncoiling of the conductor, disruption of the insulation, or complete fracture, leaving an intravascular remnant that may embolize or be a source for thrombosis. Although fixation and abandonment of an inactive chronically implanted lead is frequently appropriate and is known to pose little long-term risk, the retained inactive lead may interact adversely with a new active lead and then increase the risk of venous thrombosis, serve as a potential nidus for infection, or produce spurious electrical sensing signals that may be sensed by the pulse generator. Absolute indications for lead removal are those in which there would be a life-threatening situation if the lead were to remain in situ. In the absence of an absolute indication, the decision to proceed with extraction must be made by weighing the potential for serious morbidity or mortality against risks of the extraction technique. Techniques for lead removal include traction and open cardiotomy operations. When a portion of the lead is intravascular, forceps, snares, baskets, countertraction, or lead-transection devices may be used to retrieve the fragment.

Functionless retained pacing leads in the cardiovascular system. A complication of pacemaker treatment

Twenty one patients with retained endocardial pacemaker leads were followed during a total observation period of 1097 months to assess the incidence of complications. Two patients developed thrombosis and occlusion of the superior vena cava, which was relieved by the development of a collateral venous circulation. In one patient the broken tip of the lead migrated to a pulmonary artery but did not cause overt complications. The remaining patients were free of symptoms. One patient died for reasons unconnected with pacemaker treatment. The good toleration of retained pacemaker leads by most patients indicates that major surgical procedures to remove the lead should be reserved for patients with life threatening complications, such as persistent infection or dangerous migration of the lead or both.

Venous obstruction. A potential complication of transvenous pacemaker electrodes

Pervenous endocardial pacing using a self-contained, totally implantable system was popularized in this country by Chardack in 1965 and subsequently has become the established mode of permanent pacing. Although this intervention may be lifesaving, it is not without risk. Occlusion of major vessels incited by the presence of a pacing electrode is an extremely rare occurrence. We describe four patients who had occlusion of the axillary or subclavian veins or of the superior vena cava due to pervenous pacing electrodes. We review the literature of previous observation of venous occlusion and thromboembolic complications due to pervenous pacemakers, describe the clinical features accompanying venous obstruction, and review pathophysiology and proposals for treatment. The use of noninvasive radionuclide venography serves as a useful adjunct in the diagnosis of venous obstruction from pacing catheters.

Cardiovascular alterations induced by chronic transvenous implantation of an automatic defibrillator electrode catheter in dogs

Six dogs (three large, three small) had defibrillator electrode catheters implanted transvenously via the right jugular vein for 17 weeks. The dogs remained healthy throughout the study. At necropsy, the lead-induced cardiovascular alterations were characterized by (1) formation of a thin white fibrous sheath over portions of the lead along its course in the veins, right atrium and right ventricle; (2) adhesion of parts of the sheathed segments of the lead to the adjacent venous intima or endocardium of the right atrium, tricuspid valve and right ventricle; (3) endocardial fibrosis with foci of cartilaginous metaplasia in areas traumatized by the lead; (4) thrombus formation at ends of sheathed segments of the lead but lack of pulmonary embolism; and (5) partial penetration of the myocardium at the apex of the right ventricle by the end of the lead in two of the small dogs. The lead-induced lesions were similar in type and severity to those produced by chronically-implanted pacemaker leads.

Pulmonary embolisation of retained transvenous pacemaker electrode

When removal of an endocardial pacemaker electrode became necessary in a patient with congestive myocardiopathy, it proved to be incarcerated. Therefore, a portion of it had to be left in site after cutting the external end of the pacing catheter. During follow-up examinations the electrode was seen to migrate in the large veins and finally was found embolized into a pulmonary artery. While there have been publications on the migration of retained pacemaker electrodes before, to our knowledge this represents the first case reported with pulmonary embolization of the migrating fragment.