ICD Leads:

Abstract

The treatment of ventricular tachyarrhythmias has changed over the last 10 years. Implantable cardioverter defibrillators (ICDs), once used only as a last resort therapy, have now become the treatment of choice. This change occurred before the first results of randomized studies on ICD therapy in patients with life-threatening ventricular tachyarrhythmias were published by the end of 1997. Technological advances of ICD therapy, in particular the development of transvenous leads, were to a large extent responsible for this change. Modern leads are characterized by their multilumen design that incorporates straight wires and coiled conductors into a single electrode body. Conductors and insulation are sheathed with additional insulation layers. The most frequently used insulating materials are silicone, polyurethane, and fluoropolymers. Lead failures are an important complication of ICD therapy. Fractured conductors, compression, creeping, or insulation defects from abrasion can cause such lead dysfunctions. Chronically implanted leads will inevitably have an increased risk of failure due to defects despite all technological advances. In the light of improving survival figures in patients with ventricular tachyarrhythmias and increasing numbers of ICD implantations, lead failures are becoming a clinical problem of ever increasing importance. Therefore, the question of which lead types necessitate extraction when a certain failure occurs and which leads can be left in place. Despite continuous improvements in lead extraction systems and growing experience in their use, the extraction of any pacemaker or ICD lead is associated with some risk of complications.

Dual- versus single-coil implantable defibrillator leads: review of the literature

“…The extraction of dual-coil ICD leads may be associated with an increased risk, compared to the extraction of single-coil leads or pacing leads [1,58,59]. Extraction of dual-coil leads may be more challenging due to the larger lead diameters, nonisodiametric lead designs, positioning of the proximal SVC defibrillation coil at the angulation of the innominate vein and the SVC, and connective tissue ingrown in the defibrillation coil surface.…”

“…Extraction of dual-coil leads may be more challenging due to the larger lead diameters, nonisodiametric lead designs, positioning of the proximal SVC defibrillation coil at the angulation of the innominate vein and the SVC, and connective tissue ingrown in the defibrillation coil surface. Regarding the specific placement of the proximal defibrillation coil in dual-coil ICD lead systems, the presence of a proximal SVC defibrillation coil may add additional risk in transvenous lead extraction [1,58,59]. Several publications describe the proximal coil of dual-coil lead systems as a special technical problem, consuming additional time and increasing risk for serious complications [59][60][61]66].…”

“…Despite numerous technical improvements during the past 20 years [1,2], the rate of implantable cardioverter-defibrillator (ICD) lead failures remains high and still is a major limitation of ICD therapy [3][4][5][6][7]. A retrospective analysis of 990 patients showed lead survival rates of 85% at 5 years and 60% at 8 years [7].…”

Long-term performance of the St Jude Riata 1580–1582 ICD lead family

“…The defibrillator lead is the most fragile component of the ICD system [5]. The number of complications increases with the time that the lead is in place [5,6]. Insulation failure is the most frequent cause of lead failure, but lead fracture, loss of capture, abnormal impedance and sensing failure can also occur [5].…”

Analysis of the Lead Sensitivity Distribution in Implantable Cardioverter Defibrillator

“…Intracardiac leads consist of several electrodes that for the basic functionality of ventricular tachyarrhythmia detection and termination, are inserted transvenously into the right ventricle (Gradaus et al, 2003;Swerdlow et al, 2007). In addition to intracardiac electrodes, ICD also use the casing of the implant as an indifferent, distant electrode.…”