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Malikides O, Simantirakis E, Zacharis E, Fragkiadakis K, Kochiadakis G, Marketou M. Cardiac Remodeling and Ventricular Pacing: From Genes to Mechanics. Genes (Basel) 2024; 15:671. [PMID: 38927607 PMCID: PMC11203142 DOI: 10.3390/genes15060671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 05/17/2024] [Accepted: 05/21/2024] [Indexed: 06/28/2024] Open
Abstract
Cardiac remodeling and ventricular pacing represent intertwined phenomena with profound implications for cardiovascular health and therapeutic interventions. This review explores the intricate relationship between cardiac remodeling and ventricular pacing, spanning from the molecular underpinnings to biomechanical alterations. Beginning with an examination of genetic predispositions and cellular signaling pathways, we delve into the mechanisms driving myocardial structural changes and electrical remodeling in response to pacing stimuli. Insights into the dynamic interplay between pacing strategies and adaptive or maladaptive remodeling processes are synthesized, shedding light on the clinical implications for patients with various cardiovascular pathologies. By bridging the gap between basic science discoveries and clinical translation, this review aims to provide a comprehensive understanding of cardiac remodeling in the context of ventricular pacing, paving the way for future advancements in cardiovascular care.
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Affiliation(s)
- Onoufrios Malikides
- Department of Cardiology, University General Hospital of Heraklion, 71003 Heraklion, Greece; (E.S.); (E.Z.); (K.F.); (G.K.); (M.M.)
| | - Emmanouel Simantirakis
- Department of Cardiology, University General Hospital of Heraklion, 71003 Heraklion, Greece; (E.S.); (E.Z.); (K.F.); (G.K.); (M.M.)
- Medical School, University of Crete, 71003 Heraklion, Greece
| | - Evangelos Zacharis
- Department of Cardiology, University General Hospital of Heraklion, 71003 Heraklion, Greece; (E.S.); (E.Z.); (K.F.); (G.K.); (M.M.)
- Medical School, University of Crete, 71003 Heraklion, Greece
| | - Konstantinos Fragkiadakis
- Department of Cardiology, University General Hospital of Heraklion, 71003 Heraklion, Greece; (E.S.); (E.Z.); (K.F.); (G.K.); (M.M.)
- Medical School, University of Crete, 71003 Heraklion, Greece
| | - George Kochiadakis
- Department of Cardiology, University General Hospital of Heraklion, 71003 Heraklion, Greece; (E.S.); (E.Z.); (K.F.); (G.K.); (M.M.)
- Medical School, University of Crete, 71003 Heraklion, Greece
| | - Maria Marketou
- Department of Cardiology, University General Hospital of Heraklion, 71003 Heraklion, Greece; (E.S.); (E.Z.); (K.F.); (G.K.); (M.M.)
- Medical School, University of Crete, 71003 Heraklion, Greece
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Keiler J, Schulze M, Dreger R, Springer A, Öner A, Wree A. Quantitative and Qualitative Assessment of Adhesive Thrombo-Fibrotic Lead Encapsulations (TFLE) of Pacemaker and ICD Leads in Arrhythmia Patients-A Post Mortem Study. Front Cardiovasc Med 2020; 7:602179. [PMID: 33330664 PMCID: PMC7734031 DOI: 10.3389/fcvm.2020.602179] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/09/2020] [Indexed: 12/13/2022] Open
Abstract
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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Affiliation(s)
- Jonas Keiler
- Department of Anatomy, Rostock University Medical Center, Rostock, Germany
| | - Marko Schulze
- Department of Anatomy, Rostock University Medical Center, Rostock, Germany
| | - Ronja Dreger
- Divisions of Cardiology, Rostock University Medical Center, Rostock, Germany
| | - Armin Springer
- Medical Biology and Electron Microscopy Center, Rostock University Medical Center, Rostock, Germany
| | - Alper Öner
- Divisions of Cardiology, Rostock University Medical Center, Rostock, Germany
| | - Andreas Wree
- Department of Anatomy, Rostock University Medical Center, Rostock, Germany
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Keiler J, Schulze M, Sombetzki M, Heller T, Tischer T, Grabow N, Wree A, Bänsch D. Neointimal fibrotic lead encapsulation - Clinical challenges and demands for implantable cardiac electronic devices. J Cardiol 2017; 70:7-17. [PMID: 28583688 DOI: 10.1016/j.jjcc.2017.01.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 01/16/2017] [Indexed: 01/09/2023]
Abstract
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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Affiliation(s)
- Jonas Keiler
- Department of Anatomy, Rostock University Medical Center, Rostock, Germany.
| | - Marko Schulze
- Department of Anatomy, Rostock University Medical Center, Rostock, Germany
| | - Martina Sombetzki
- Department for Tropical Medicine and Infectious Diseases, Rostock University Medical Center, Rostock, Germany
| | - Thomas Heller
- Institute of Diagnostic and Interventional Radiology, Rostock University Medical Center, Rostock, Germany
| | - Tina Tischer
- Heart Center Rostock, Department of Internal Medicine, Divisions of Cardiology, Rostock University Medical Center, Rostock, Germany
| | - Niels Grabow
- Institute for Biomedical Engineering, Rostock University Medical Center, Rostock, Germany
| | - Andreas Wree
- Department of Anatomy, Rostock University Medical Center, Rostock, Germany
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Zhou L, Vest AN, Peck RA, Sredl JP, Huang X, Bar-Cohen Y, Silka MJ, Pruetz JD, Chmait RH, Loeb GE. Minimally invasive implantable fetal micropacemaker: mechanical testing and technical refinements. Med Biol Eng Comput 2016; 54:1819-1830. [PMID: 27021067 PMCID: PMC5040620 DOI: 10.1007/s11517-016-1470-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 02/15/2016] [Indexed: 11/24/2022]
Abstract
This paper discusses the technical and safety requirements for cardiac pacing of a human fetus with heart failure and hydrops fetalis secondary to complete heart block. Engineering strategies to meet specific technical requirements were integrated into a systematic design and implementation consisting of a novel fetal micropacemaker, a percutaneous implantation system, and a sterile package that enables device storage and recharging maintenance in a clinical setting. We further analyzed observed problems on myocardial fixation and pacing lead fatigue previously reported in earlier preclinical trials. This paper describes the technical refinements of the implantable fetal micropacemaker to overcome these challenges. The mechanical performance has been extensively tested to verify the improvement of reliability and safety margins of the implantation system.
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Affiliation(s)
- Li Zhou
- Medical Device Development Facility, Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, 1042 Downey Way, Los Angeles, CA, 90089, USA.
| | - Adriana Nicholson Vest
- Medical Device Development Facility, Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, 1042 Downey Way, Los Angeles, CA, 90089, USA
| | - Raymond A Peck
- Medical Device Development Facility, Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, 1042 Downey Way, Los Angeles, CA, 90089, USA
| | - Jonathan P Sredl
- Medical Device Development Facility, Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, 1042 Downey Way, Los Angeles, CA, 90089, USA
| | - Xuechen Huang
- Medical Device Development Facility, Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, 1042 Downey Way, Los Angeles, CA, 90089, USA
| | - Yaniv Bar-Cohen
- Division of Cardiology, Department of Pediatrics, Children's Hospital of Los Angeles, 4650 Sunset, Los Angeles, CA, 90027, USA
- Keck School of Medicine, University of Southern California, 1975 Zonal Ave, Los Angeles, CA, 90033, USA
| | - Michael J Silka
- Division of Cardiology, Department of Pediatrics, Children's Hospital of Los Angeles, 4650 Sunset, Los Angeles, CA, 90027, USA
- Keck School of Medicine, University of Southern California, 1975 Zonal Ave, Los Angeles, CA, 90033, USA
| | - Jay D Pruetz
- Division of Cardiology, Department of Pediatrics, Children's Hospital of Los Angeles, 4650 Sunset, Los Angeles, CA, 90027, USA
- Keck School of Medicine, University of Southern California, 1975 Zonal Ave, Los Angeles, CA, 90033, USA
- Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, 1300 North Vermont Avenue, Suite 710, Los Angeles, CA, 90027, USA
| | - Ramen H Chmait
- Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, 1300 North Vermont Avenue, Suite 710, Los Angeles, CA, 90027, USA
| | - Gerald E Loeb
- Medical Device Development Facility, Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, 1042 Downey Way, Los Angeles, CA, 90089, USA
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Kolodzinska A, Kutarski A, Koperski L, Grabowski M, Malecka B, Opolski G. Differences in encapsulating lead tissue in patients who underwent transvenous lead removal. Europace 2012; 14:994-1001. [DOI: 10.1093/europace/eur384] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Dvorak P, Novak M, Kamaryt P, Slana B, Lipoldova J, Dvorak P. Histological findings around electrodes in pacemaker and implantable cardioverter-defibrillator patients: comparison of steroid-eluting and non-steroid-eluting electrodes. Europace 2011; 14:117-23. [DOI: 10.1093/europace/eur274] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Yamazaki KG, Villarreal FJ. Ventricular pacing-induced loss of contractile function and development of epicardial inflammation. Am J Physiol Heart Circ Physiol 2011; 300:H1282-90. [PMID: 21297025 DOI: 10.1152/ajpheart.01079.2010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Perturbations in the normal sequence of ventricular activation can create regions of early and late activation, leading to dysynchronous contraction and areas of dyskinesis. Dyskinesis occurs across the left ventricular (LV) wall, and its presence may have important consequences on cardiac structure and function in normal and failing hearts. Acutely, dyskinesis can trigger inflammation and, in the long term (6 wk and above), leads to LV remodeling. The mechanisms that trigger these changes are unknown. To gain further insight, we used a canine model to evaluate transumural changes in myocardial function and inflammation induced by epicardial LV pacing. The results indicate that 4 h of LV suprathreshold pacing resulted in a 30% local loss of endocardial thickening. Assessment of neutrophil infiltration showed a significant approximately fivefold increase in myeloperoxidase activity in the epicardium versus the midwall/endocardium. Matrix metalloproteinase-9 activity increased ∼2 fold in the epicardium and ROS generation increased ∼2.5-fold compared with the midwall/endocardium. To determine the effects that electrical current alone has on these end points, a group of animals was subjected to subthreshold pacing. Significant increases were observed only in epicardial myeloperoxidase levels. Thus, the results indicate that transmural dyskinesis induced by suprathreshold epicardial LV activation triggers a localized epicardial inflammatory response, whereas subthreshold stimulation appears to solely induce the trapping of leucocytes. Suprathreshold pacing also induces a loss of endocardial function. These results may have important implications as to the nature of the mechanisms that trigger the inflammatory response and possibly long-term remodeling in the setting of dysynchrony.
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Affiliation(s)
- Katrina Go Yamazaki
- Departments of 1Pharmacology, University of California-San Diego, La Jolla, 92093-0613, USA
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Nikolaou NI, Spanodimos SG, Tsaglis EP, Antonatos DG, Patsilinakos SP, Fournarakis GM, Tsigas DL. Biochemical Evidence of Cardiac Damage Following Transvenous Implantation of a Permanent Antibradycardia Pacemaker Lead. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2005; 28:1174-81. [PMID: 16359283 DOI: 10.1111/j.1540-8159.2005.50136.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES We tested the hypothesis that transvenous permanent pacemaker lead implantation causes clinically detectable myocardial damage. BACKGROUND Histological evidence of myocardial damage has been reported after antibradycardia pacemaker lead implantation. METHODS We studied 30 patients undergoing implantation of a full antibradycardia pacemaker system (pulse generator plus leads) and 10 patients in whom only a generator was implanted. Blood samples for cardiac troponin-I (CTNI), CK-MB mass, and myoglobin measurement were drawn at baseline, at the end of the procedure, and at 2, 6, 12, 24, 48, and 72 hours thereafter. RESULTS Abnormal CTNI levels were noted only in 24 of the 30 patients undergoing a full system implantation. CTNI levels were already abnormal at the end of the procedure in 16 and became so in all 24 during the next 6 hours. Peak levels were reached within 6 hours in 21 patients and were compatible with "minimal" necrosis (CTNI < 1.5 pg/mL) in 20. Maximum ventricular lead diameter and number of implanted leads were independent predictors of peak CTNI levels. CK-MB mass also increased after the procedure, but exceeded the normal range in only 10 patients. Myoglobin levels increased significantly both in patients undergoing a complete system implantation and in those where only a pulse generator was implanted. CONCLUSIONS Transvenous insertion of endocardial leads for permanent pacing is accompanied in most patients by "minimal" myocardial damage. In this setting CTNI level kinetics are fast, characterized by early elevation and peak.
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Affiliation(s)
- Nikolaos I Nikolaou
- Department of Cardiology, Konstantopoulio-Agia Olga General Hospital, Athens, Greece.
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Esposito M, Kennergren C, Holmström N, Nilsson S, Eckerdal J, Thomsen P. Morphologic and immunohistochemical observations of tissues surrounding retrieved transvenous pacemaker leads. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2003; 63:548-58. [PMID: 12209900 DOI: 10.1002/jbm.10306] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Immunohistochemical and morphologic techniques were employed to evaluate the tissue response around chronically implanted pacing leads. Seventeen leads were retrieved from 12 patients. Leads were extracted by direct manual traction (1), extraction with sheaths and locking stylets (1), or with by a combination of mechanical tools and Excimer laser sheaths (15). Mean lead implantation time was 5.6 years (range 1-8 years). Frozen sections, 6-8 microm thick, were incubated with antibodies against HLA-DR antigen, endothelial cells, macrophages, T cells, plasma cells, fibrinogen, and interleukin-1beta. Prominent morphologic observations were fibrous encapsulations of the leads. Immunohistochemical analysis revealed a tissue generally devoid of inflammatory and immune cells. The fibrous capsule surrounding the lead was partially or completely covered with a monolayer of CD34 expressing endothelial cells. The results from this study provide useful information in design and material selection for pacemaker leads. Endothelialization of the fibrous encapsulation indicates a functionalization of blood-contacting surfaces around pacemaker materials, thus providing a mechanism for long-term persistence of foreign materials in the blood. The laser method allowed an efficient extraction of pacemaker leads without damage to the studied tissues, as suggested by the presence of immunolabeled cells close to the cut surfaces.
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Affiliation(s)
- Marco Esposito
- Department of Biomaterials, The Sahlgrenska Academy at Göteborg University, Göteborg, Sweden.
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Higashi Y, Sato T, Shimojima H, Takeyama Y, Goto K, Mitsuya T, Sagawa F, Ishikawa R, Ishikawa Y. Mechanism of decrease in the atrial potential after implantation of a single-lead VDD pacemaker: atrial histological changes after implantation of a VDD pacemaker lead in dogs. Pacing Clin Electrophysiol 2003; 26:685-91. [PMID: 12698668 DOI: 10.1046/j.1460-9592.2003.00118.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The single-lead VDD pacemaker system (VDDPS) enables atrial synchronous ventricular pacing with only one lead in patients with an atrioventricular block. There are some cases in which the atrial potential decreases after implantation of a VDDPS, making physiological pacing difficult. The mechanism of this decrease has not been elucidated yet. To elucidate the possible relationship between the decrease of the atrial potential after implantation of a VDDPS and histopathological changes of the atrium. We implanted a VDDPS from the jugular vein under anesthesia in 10 adult dogs. The tip of the pacing lead was fixed in the right ventricular apex of the heart under fluoroscopic guidance. Then, the lead was ligated and fixed to the jugular vein at a point where a favorable atrial potential was obtained. The end of the lead was passed from the neck to the back subcutaneously; then pulled outside and fixed there to measure the atrial potential. The atrial potential was measured using a pacing system analyzer under anesthesia on days 3 (n = 9) and 7 (n = 8), as well as on weeks 2 (n = 6), 3 (n = 4), and 4 (n = 3), after the implantation. The heart was removed from the dogs on day 3 (n = 2), day 7 (n = 2), week 2 (n = 2), and week 4 (n = 4) to examine the atrial histological findings. The atrial potential was 2.7 +/- 0.7 mV at the time of the implantation, 1.7 +/- 1.1 mV (P < 0.05) on day 3, and 1.7 +/- 0.7 mV on week 4 after the implantation. Macroscopically, the pacemaker lead was covered with thrombus, and adhered to the atrial wall in 80% of animals. Microscopically, the endocardium was hypertrophic due to fibrous tissue; besides RBC extravasation, inflammatory cells infiltration and degeneration of myocardial cells, were observed under the endocardium. Inflammatory changes developed in the atrial wall after implantation of the VDDPS, and this seemed to be one of the mechanisms for the decrease of the atrial potential of the VDDPS.
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Affiliation(s)
- Yukei Higashi
- Cardiovascular Division, Showa University Fujigaoka Hospital, 1-30 Fujigaoka Aoba-ku, Yokohama, Japan 227-8501.
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Cox JN. Pathology of cardiac pacemakers and central catheters. CURRENT TOPICS IN PATHOLOGY. ERGEBNISSE DER PATHOLOGIE 1994; 86:199-271. [PMID: 8162711 DOI: 10.1007/978-3-642-76846-0_6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- J N Cox
- Department of Pathology, CMU, Geneva, Switzerland
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12
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Rosenberg PH, Oramas AG, Nelson RL, Hall MH, Tortolani AJ. Epicardial lead failure due to dense scarring: a solution. Ann Thorac Surg 1991; 52:346-7. [PMID: 1863168 DOI: 10.1016/0003-4975(91)91379-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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13
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Radovsky AS, Van Vleet JF. Effects of dexamethasone elution on tissue reaction around stimulating electrodes of endocardial pacing leads in dogs. Am Heart J 1989; 117:1288-98. [PMID: 2658520 DOI: 10.1016/0002-8703(89)90408-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A pair of endocardial pacemaker leads, identical except for the presence or absence of dexamethasone elution from the distal stimulating electrode, was implanted into the right ventricle of each of 12 dogs for either 3 weeks (n = six pairs) or 6 weeks (n = six pairs). Fibrous connective tissue sheaths (0.04 to 0.20 mm thick) formed around the distal porous-surfaced stimulating electrodes because of proliferation of endocardial connective tissue and adherence and organization of thrombus. Connective tissue sheaths were composed of fibroblasts within an abundant collagen matrix and contained scattered macrophages, lymphocytes, plasma cells, and mast cells. Connective tissue sheaths around dexamethasone-eluting leads were thinner (p less than 0.03), less cellular (p less than 0.10), and had fewer mast cells (p less than 0.10) than corresponding nonsteroid leads. There was mild multifocal interstitial fibrosis, myofiber atrophy, and myofibrillar lysis in the adjacent myocardium. Thresholds for electrical stimulation of the myocardium were consistently lower for pacing leads with dexamethasone-eluting stimulating electrodes than for leads without dexamethasone.
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Affiliation(s)
- A S Radovsky
- Department of Veterinary Pathobiology, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907
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