Drug release mechanisms of steroid eluting rings in cardiac pacemaker lead electrodes

Herrlich, Simon; Spieth, Sven; Gerstmann, Hans; Virnich, Astrid; Zipfel, Franz; Kitschmann, Achim; Goettsche, T.; Osypka, P; Zengerle, Roland

doi:10.1109/embc.2012.6346023

Cited by 4 publications

(5 citation statements)

References 19 publications

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“…If the electrical field around the myocardial cells reaches its threshold voltage, voltage-gated sodium channels open on the cell membrane and an action potential is generated 8 . As the amount of myocardial fibrosis increases, increased tissue impedance reduces myocardial conductivity and delays electrical signal propagation, contributing to a higher pacing threshold 6 . Reducing myocardial tissue impedance can therefore decrease the depolarization threshold.…”

Section: Discussionmentioning

confidence: 99%

“…The local stimulation of the pacemaker leads often induces further regional fibrosis 3 , which will require greater stimulation to maintain cardiac rhythm. Therefore, pacemaker threshold is an important parameter for measuring energy consumption and tissue damage 4 - 6 . Alteration of the interface between the myocardium and the stimulator, in order to reduce the threshold, is helpful for pacemaker efficiency.…”

Section: Introductionmentioning

confidence: 99%

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Injectable conductive hydrogel can reduce pacing threshold and enhance efficacy of cardiac pacemaker

et al. 2021

Theranostics

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Background: Pacemaker implantation is currently used in patients with symptomatic bradycardia. Since a pacemaker is a lifetime therapeutic device, its energy consumption contributes to battery exhaustion, along with its voltage stimulation resulting in local fibrosis and greater resistance, which are all detrimental to patients. The possible resolution for those clinical issues is an injection of a conductive hydrogel, poly-3-amino-4-methoxybenzoic acid-gelatin (PAMB-G), to reduce the myocardial threshold voltage for pacemaker stimulation. Methods: PAMB-G is synthesized by covalently linking PAMB to gelatin, and its conductivity is measured using two-point resistivity. Rat hearts are injected with gelatin or PAMB-G, and pacing threshold is evaluated using electrocardiogram and cardiac optical mapping. Results: PAMB-G conductivity is 13 times greater than in gelatin. The ex vivo model shows that PAMB-G significantly enhances cardiac tissue stimulation. Injection of PAMB-G into the stimulating electrode location at the myocardium has a 4 times greater reduction of pacing threshold voltage, compared with electrode-only or gelatin-injected tissues. Multi-electrode array mapping reveals that the cardiac conduction velocity of PAMB-G group is significantly faster than the non- or gelatin-injection groups. PAMB-G also reduces pacing threshold voltage in an adenosine-induced atrial-ventricular block rat model. Conclusion: PAMB-G hydrogel reduces cardiac pacing threshold voltage, which is able to enhance pacemaker efficacy.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Injectable conductive hydrogel can reduce pacing threshold and enhance efficacy of cardiac pacemaker

et al. 2021

Theranostics

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“…Moderate to strong foreign body reactions which are common after implantations (40) can occur at the vessel-lead interface (34) potentially impeding transmural electric impulse transfer by fibrotization of subendocardial myocardial tissue and thus increasing excitation thresholds (41,42).…”

Section: Tfle Formationmentioning

confidence: 99%

Quantitative and Qualitative Assessment of Adhesive Thrombo-Fibrotic Lead Encapsulations (TFLE) of Pacemaker and ICD Leads in Arrhythmia Patients—A Post Mortem Study

Keiler

Schulze

Dreger

et al. 2020

Front. Cardiovasc. Med.

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The demand for cardiac implantable electronic devices for arrhythmia therapy is still unabated and rising. Despite onward optimizations, lead-related problems such as infections or fractures often necessitate lead extraction. Due to adhesive thrombo-fibrotic lead encapsulations (TFLE) transvenous lead extraction is challenging and risky. However, knowledge on TFLEs and possible correlations with technical lead parameters and dwelling time (DT) were hitherto insufficiently studied. Therefore, we analyzed TFLEs of 62 lead from 35 body donor corpses to gain information for a potential lead design optimization. We examined both TFLE topography on the basis on anatomical landmarks and histo-morphological TFLE characteristics by means of histological paraffin sections and scanning electron microscopy of decellularized samples. The macroscopic analysis revealed that all leads were affected by TFLEs, mainly in the lead bearing veins. Half (47.2%) of the right-ventricular leads possessed adhesions to the tricuspid valve. On average, 49.9 ± 21.8% of the intravascular lead length was covered by TFLE of which 82.8 ± 16.2% were adhesive wall bindings (WB). The discrete TFLEs with at least one WB portion had a mean length of 95.0 ± 64.3 mm and a maximum of 200 mm. Neither sex, DT nor certain technical lead parameters showed distinct tendencies to promote or prevent TFLE. TFLE formation seems to start early in the first 1–2 weeks after implantation. The degree of fibrotization of the TFLE, starting with a thrombus, was reflected by the amount of compacted collagenous fibers and likewise largely independent from DT. TFLE thickness often reached several hundred micrometers. Calcifications were occasionally seen and appeared irregularly along the TFLE sheath. Leadless pacemaker systems have the advantage to overcome the problem with TFLEs but hold their own specific risks and limitations which are not fully known yet.

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“…1) [9,15,[37][38][39][40][41][42]. Moreover, it is believed that the newly formed tissue sheath at the lead coils in ICDs can also result in an unfavorable higher threshold [43,44].…”

Section: Lead Issuesmentioning

confidence: 99%

“…Steroideluting sections on lead tips are particularly beneficial for actively anchored leads reducing the initial fibrotic reaction and thereby preventing a higher pacing or defibrillation threshold [157]. The glucocorticosteroid derivatives used most commonly for siliconized pacemaker leads are dexamethasone acetate (DexA) and dexamethasone sodium phosphate (DexP) [43]. The incorporation of drug-eluting systems into the insulation sheath might be a possible strategy to suppress neointimal and fibrotic formation around the lead in being similar to systems already used in coronary stents [158] or stented vascular grafts [159] to reduce neointimal and medial thickening.…”

Section: Strategies To Avoid Lead Issuesmentioning

confidence: 99%

Neointimal fibrotic lead encapsulation – Clinical challenges and demands for implantable cardiac electronic devices

Keiler

Schulze

Sombetzki

et al. 2017

Journal of Cardiology

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Every tenth patient with a cardiac pacemaker or implantable cardioverter-defibrillator implanted is expected to have at least one lead problem in his lifetime. However, transvenous leads are often difficult to remove due to thrombotic obstruction or extensive neointimal fibrotic ingrowth. Despite its clinical significance, knowledge on lead-induced vascular fibrosis and neointimal lead encapsulation is sparse. Although leadless pacemakers are already available, their clinical operating range is limited. Therefore, lead/tissue interactions must be further improved in order to improve lead removals in particular. The published data on the coherences and issues related to lead associated vascular fibrosis and neointimal lead encapsulation are reviewed and discussed in this paper.

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Drug release mechanisms of steroid eluting rings in cardiac pacemaker lead electrodes

Cited by 4 publications

References 19 publications

Injectable conductive hydrogel can reduce pacing threshold and enhance efficacy of cardiac pacemaker

Injectable conductive hydrogel can reduce pacing threshold and enhance efficacy of cardiac pacemaker

Quantitative and Qualitative Assessment of Adhesive Thrombo-Fibrotic Lead Encapsulations (TFLE) of Pacemaker and ICD Leads in Arrhythmia Patients—A Post Mortem Study

Neointimal fibrotic lead encapsulation – Clinical challenges and demands for implantable cardiac electronic devices

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