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Almehmadi F, Manlucu J. Should Single-Coil Implantable Cardioverter Defibrillator Leads Be Used in all Patients? Card Electrophysiol Clin 2018; 10:59-66. [PMID: 29428142 DOI: 10.1016/j.ccep.2017.11.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The historical preference for dual-coil implantable cardioverter defibrillator leads stems from high defibrillation thresholds associated with old device platforms. The high safety margins generated by contemporary devices have rendered the modest difference in defibrillation efficacy between single- and dual-coil leads clinically insignificant. Cohort data demonstrating worse lead extraction outcomes and higher all-cause mortality have brought the incremental utility of an superior vena cava coil into question. This article summarizes the current literature and re-evaluates the utility of dual-coil leads in the context of modern device technology.
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Affiliation(s)
- Fahad Almehmadi
- Division of Cardiology, Department of Medicine, Western University, PO Box 5339, 339 Windermere Road, Room B6-127, London, Ontario N6A 5A5, Canada
| | - Jaimie Manlucu
- Division of Cardiology, Department of Medicine, Western University, PO Box 5339, 339 Windermere Road, Room B6-127, London, Ontario N6A 5A5, Canada.
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2
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Uyguanco ER, Berger A, Budzikowski AS, Gunsburg M, Kassotis J. Management of high defibrillation threshold. Expert Rev Cardiovasc Ther 2014; 6:1237-48. [DOI: 10.1586/14779072.6.9.1237] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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3
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Comparison of defibrillation efficacy between two pads placements in a pediatric porcine model of cardiac arrest. Resuscitation 2012; 83:755-9. [DOI: 10.1016/j.resuscitation.2011.12.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 12/05/2011] [Accepted: 12/08/2011] [Indexed: 11/21/2022]
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4
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Neuzner J, Carlsson J. Dual- versus single-coil implantable defibrillator leads: review of the literature. Clin Res Cardiol 2012; 101:239-45. [DOI: 10.1007/s00392-011-0407-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 12/23/2011] [Indexed: 11/25/2022]
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5
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Reynolds CR, Nikolski V, Sturdivant JL, Leman RB, Cuoco FA, Wharton JM, Gold MR. Randomized comparison of defibrillation thresholds from the right ventricular apex and outflow tract. Heart Rhythm 2010; 7:1561-6. [DOI: 10.1016/j.hrthm.2010.06.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Accepted: 06/09/2010] [Indexed: 11/28/2022]
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6
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VARMA NIRAJ, EFIMOV IGOR. Right Pectoral Implantable Cardioverter Defibrillators: Role of the Proximal (SVC) Coil. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2008; 31:1025-35. [DOI: 10.1111/j.1540-8159.2008.01130.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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7
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Michael KA, Veldtman GR, Paisey JR, Yue AM, Robinson S, Allen S, Sunni NS, Kiesewetter C, Salmon T, Roberts PR, Morgan JM. Cardiac defibrillation therapy for at risk patients with systemic right ventricular dysfunction secondary to atrial redirection surgery for dextro-transposition of the great arteries. ACTA ACUST UNITED AC 2007; 9:281-4. [PMID: 17383987 DOI: 10.1093/europace/eum001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIM To review techniques of implantable cardioverter-defibrillators (ICD) in patients after Mustard surgery for arterial transposition. METHODS AND RESULTS Retrospective analysis of all Mustard patients receiving ICDs at our institution. Five patients (median age 24 years, range 19-35, 3 male) with systemic right ventricular dysfunction (sRV) dysfunction and New York Heart Association (NYHA) II and III, received ICDs. Implantation was performed transvenously in three patients, epicardial patches and subcutaneous arrays at surgery in two patients. Two patients required lead extraction and baffle stent angioplasty before ICD implantation. Defibrillation vectors incorporating the anterior sRV mass [i.e., sub-pulmonary left ventricle (pLV) to generator can, and between epicardial defibrillator patches], consistently achieved a minimum 10 joule(J) safety margin during defibrillation threshold (DFT) testing. Subcutaneous arrays and endocardial vectors that included a superior vena cava (SVC) electrode were less effective. One patient developed pulmonary oedema post-procedure. At a median 20 months, all patients were alive and in NYHA class II. Follow-up over 24 months documented multiple non-sustained ventricular tachycardia (VT) in the group and one patient had recurrent VT with aborted device therapy. CONCLUSION Defibrillator implantation in Mustard patients is challenging. Sub-optimal defibrillation should be anticipated and can be overcome using vectors which integrate the RV mass and high-energy devices. A staged procedure involving pre-implant interventions or separate DFT tests, where indicated, may be better tolerated by patients.
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Affiliation(s)
- Kevin A Michael
- Department of Clinical Electrophysiology, Wessex Cardiothoracic Centre, Southampton, UK.
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8
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Eckart RE, Hruczkowski TW, Stevenson WG, Epstein LM. Myopotentials Leading to Ventricular Fibrillation Detection After Advisory Defibrillator Generator Replacement. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2006; 29:1273-6. [PMID: 17100683 DOI: 10.1111/j.1540-8159.2006.00531.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
We present an unusual source of oversensing following an internal cardioverter-defibrillator generator change. The early appearance of reproducible myopotentials in the defibrillator sensing channel is usually due to a technical complication at the time of device implantation. Clues such as abrupt impedance change or reproduction with mechanical stimulation can help to localize a problem. Frequently the complication requires reoperation to examine the system. What do you do when everything seems to be working fine?
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Affiliation(s)
- Robert E Eckart
- Cardiac Arrhythmia Service, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
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9
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Affiliation(s)
- Sumeet K Mainigi
- Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, 19104, USA
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10
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Kirk MM, Shorofsky SR, Gold MR. Comparison of the effects of active left and right pectoral pulse generators on defibrillation efficacy. Am J Cardiol 2001; 88:1308-11. [PMID: 11728363 DOI: 10.1016/s0002-9149(01)02096-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- M M Kirk
- Department of Medicine, Division of Cardiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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11
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Sun SS, Huang JL, Tsai SC, Ho YJ, Kao CH. The higher likelihood of developing cardiomegaly during follow-up in patients with syndrome X and abnormal thallium-201 myocardial perfusion SPECT. Int J Cardiovasc Imaging 2001; 17:271-8. [PMID: 11599866 DOI: 10.1023/a:1011661300903] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
'Syndrome X' describes patients with exertional chest pain and a normal coronary arteriogram. In some patients, acute myocardial ischemia can be demonstrated by regional myocardial perfusion defects on thallium-201 exercise test. However, some patients with typical angina have normal perfusion on thallium-201 heart scintigraphy. It is not clear whether there are different prognoses for patients with normal and abnormal thallium studies. In this study, the clinical features, long term follow-up and clinical results of syndrome X patients with normal and abnormal thallium studies were evaluated to determine the differences between these two groups. Fifty-nine patients (52 males, seven females, mean age 62+/-6 years) with syndrome X were enrolled and divided into two groups on the basis of results of thallium-201 heart scintigraphy. Group I was comprised of 22 patients with normal thallium-201 perfusion scan and group II was comprised of 37 patients with abnormal thallium-201 heart scan. All subjects received coronary arteriography, exercise test, thallium-201 myocardial SPECT, ejection fraction of left ventricle, echocardiography, blood analysis and long term follow-up with questionnaire for 10 years. Lower maximal rate-pressure product and higher angina scores were found in group II. More patients developed cardiomegaly (nine of 33 patients) in group II than in group I (one of 21 patients). Both groups, however, were at low risk for cardiac events (cardiac death or myocardial infarction).
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Affiliation(s)
- S S Sun
- Department of Nuclear Medicine, China Medical College Hospital, Taichung, Taiwan
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12
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Shalaby AA, Demers PA, Sager PT, Bersohn MM. Placement of a defibrillation lead in the left subclavian vein from the right cephalic vein. Pacing Clin Electrophysiol 2000; 23:1318-9. [PMID: 10962762 DOI: 10.1111/j.1540-8159.2000.tb00954.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This case report highlights the feasibility and stability of transvenous placement of a second defibrillation lead in the left subclavian vein from a right cephalic vein approach. This was undertaken in a right-sided implant of an active can cardioverter defibrillator to lower defibrillation thresholds that would have otherwise precluded implant.
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Abstract
We describe a 23-year-old patient with idiopathic dilated cardiomyopathy in whom an implantable cardioverter defibrillator was implanted via the right external iliac vein. Addition of a subcutaneous patch was required to obtain an adequate safety margin for defibrillation.
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Affiliation(s)
- S L Pinski
- Section of Cardiology, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612, USA.
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14
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Gold MR, Olsovsky MR, DeGroot PJ, Cuello C, Shorofsky SR. Optimization of transvenous coil position for active can defibrillation thresholds. J Cardiovasc Electrophysiol 2000; 11:25-9. [PMID: 10695457 DOI: 10.1111/j.1540-8167.2000.tb00731.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Lead systems that include an active pectoral pulse generator are now standard for initial defibrillator implantations. However, the optimal transvenous lead system and coil location for such active can configurations are unknown. The purpose of this study was to evaluate the benefit and optimal position of a superior vena cava (SVC) coil on defibrillation thresholds with an active left pectoral pulse generator and right ventricular coil. METHODS AND RESULTS This prospective, randomized study was performed on 27 patients. Each subject was evaluated with three lead configurations, with the order of testing randomized. Biphasic shocks were delivered between the right ventricular coil and an active can alone (unipolar), or an active can in common with the proximal coil positioned either at the right atrial/SVC junction (low SVC) or in the left subclavian vein (high SVC). Stored energies at defibrillation threshold were higher for the single-coil, unipolar configuration (11.2 +/- 6.6 J) than for the high (8.9 +/- 4.2 J) or low (8.5 +/- 4.2 J) SVC configurations (P < 0.01). Moreover, 96% of subjects had low (< or = 15 J) thresholds with the SVC coil in either position compared with 81% for the single-coil configuration. Shock impedance (P < 0.001) was increased with the unipolar configuration, whereas peak current was reduced (P < 0.001). CONCLUSION The addition of a proximal transvenous coil to an active can unipolar lead configuration reduces defibrillation energy requirements. The position of this coil has no significant effect on defibrillation thresholds.
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Affiliation(s)
- M R Gold
- Department of Medicine, University of Maryland School of Medicine, Baltimore 21201, USA.
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15
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Min X, Mehra R. Finite element analysis of defibrillation fields in a human torso model for ventricular defibrillation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 1998; 69:353-86. [PMID: 9785946 DOI: 10.1016/s0079-6107(98)00015-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In order to optimize defibrillation electrode systems for ventricular defibrillation thresholds (DFTs), a Finite Element Torso model was built from fast CT scans of a patient who had large cardiac dimensions (upper bound of normal) but no heart disease. Clinically used defibrillation electrode configurations, i.e. Superior Vena Cava (SVC) to Right Ventricle (RV) (SVC-RV), left pectoral Can to RV (Can-RV) and Can + SVC-RV, were analyzed. The DFTs were calculated based on 95% ventricular mass having voltage gradient > 5 V/cm and these results were also compared with clinical data. The low voltage gradient regions with voltage gradient < 5 V/cm were identified and the effect of electrode dimension and location on DFTs were also investigated for each system. A good correlation between the model results and the clinical data supports the use of Finite Element Analysis of a human torso model for optimization of defibrillation electrode systems. This correlation also indicates that the critical mass hypothesis is the primary mechanism of defibrillation. Both the FEA results and the clinical data show that Can + SVC-RV system offers the lowest voltage DFTs when compared with SVC-RV and Can-RV systems. Analysis of the effect of RV, SVC and Can electrode dimensions and locations can have an important impact on defibrillation lead designs.
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Affiliation(s)
- X Min
- Medtronic, Minneapolis, MN 55432, USA.
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16
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Winter J, Heil JE, Schumann C, Lin Y, Schannwell CM, Michel U, Schipke JD, Schulte HD, Gams E. Effect of implantable cardioverter/defibrillator lead placement in the right ventricle on defibrillation energy requirements. A combined experimental and clinical study. Eur J Cardiothorac Surg 1998; 14:419-25. [PMID: 9845149 DOI: 10.1016/s1010-7940(98)00215-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
OBJECTIVES The effect of implantable cardioverter/defibrillator (ICD) lead placement in the right ventricle (RV) on defibrillation efficacy has not been thoroughly investigated. Therefore, the goal of this combined experimental and clinical study was to evaluate the effect of a septal and a non-septal position of the right ventricular endocardial spring lead on defibrillation energy. METHODS In 12 isoflurane-anaesthetized swine and subsequently in 8 patients who underwent ICD implantation, two different positions of the distal spring lead in the RV were investigated in randomized order: non-septal position (free wall of the RV) and septal position (interventricular septum). For each position, separate 50% probability determinations of energy (E50), peak voltage (V50) and peak current (A50) were calculated using the three reversal up/down defibrillation procedure. The E50, V50, A50 and impedance (I) were averaged and compared using the two-sided t-test for paired samples. RESULTS Both the experimental study and the clinical study demonstrated that placing the distal defibrillation lead near to the septum rather than near to the ventricular free wall resulted both in the swine and in the patients in significantly lower E50-31.6%/ - 37.1%, V50-16.1%/-20.9% and A50 -10.0%/ - 24.2%, respectively. Defibrillation impedances were significantly reduced only in the experimental study. CONCLUSIONS Defibrillation efficacy depends on the position of the distal spring electrode in the RV. A septal position significantly reduces the energy requirements compared to a non-septal position. The decrease in energy requirements might be explained by an increase in current flow through the septum and the posterolateral wall of the left ventricle. reserved
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Affiliation(s)
- J Winter
- Department of Thoracic and Cardiovascular Surgery, Heinrich-Heine-University, Duesseldorf, Germany
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17
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Gold MR, Olsovsky MR, Pelini MA, Peters RW, Shorofsky SR. Comparison of single- and dual-coil active pectoral defibrillation lead systems. J Am Coll Cardiol 1998; 31:1391-4. [PMID: 9581739 DOI: 10.1016/s0735-1097(98)00103-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES The purpose of this study was to compare defibrillation thresholds with lead systems consisting of an active left pectoral electrode and either single or dual transvenous coils. BACKGROUND Lead systems that include an active pectoral pulse generator reduce defibrillation thresholds and permit transvenous defibrillation in nearly all patients. A further improvement in defibrillation efficacy is desirable to allow for smaller pulse generators with a reduced maximal output. METHODS This prospective study was performed in 50 consecutive patients. Each patient was evaluated with two lead configurations with the order of testing randomized. Shocks were delivered between the right ventricular coil and either an active can alone (single coil) or an active can with the proximal atrial coil (dual coil). The right ventricular coil was the cathode for the first phase of the biphasic defibrillation waveform. RESULTS Delivered energy at the defibrillation threshold was 10.1+/-5.0 J for the single-coil configuration and 8.7+/-4.0 J for the dual-coil configuration (p < 0.02). Moreover, 98% of patients had low (<15 J) thresholds with the dual-coil lead system, compared with 88% of patients with the single-coil configuration (p=0.05). Leading edge voltage (p < 0.001) and shock impedance (p < 0.001) were also decreased with the dual-coil configuration, although peak current was increased (p < 0.001). CONCLUSIONS A dual-coil, active pectoral lead system reduces defibrillation energy requirements compared with a single-coil, unipolar configuration.
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Affiliation(s)
- M R Gold
- Department of Medicine, University of Maryland School of Medicine, Baltimore, USA.
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Flaker GC, Tummala R, Wilson J. Comparison of right- and left-sided pectoral implantation parameters with the Jewel active can cardiodefibrillator. The World Wide Jewel Investigators. Pacing Clin Electrophysiol 1998; 21:447-51. [PMID: 9507547 DOI: 10.1111/j.1540-8159.1998.tb00070.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A total of 1,207 patients received a Medtronic Jewel active can ICD (models 7218C, 7219C), with a Transvene lead in 97 centers in Europe and North America. Nineteen implants were from the right pectoral region. Patients with right-sided ICDs did not differ in terms of mean age, % male, left ventricular ejection fraction, New York Heart Association Functional Class, antiarrhythmic drug therapy, indication for the implantable cardioverter defibrillator, and R wave values at implantation, but tended to have slightly higher pacing thresholds (1.2 +/- 0.5 V vs 1.0 +/- 0.6 V, P = 0.012) and higher defibrillation thresholds (14.7 +/- 6.4 J vs 11.5 +/- 6 J, P = 0.11) compared with patients with left sided implants. Patients with right-sided implants had a longer implantation time compared with patients with left-sided implants (118 +/- 70 minutes vs 91 +/- 46 minutes, P = 0.074). In follow-up, 5 patients with right-sided implantation received successful therapy for either ventricular fibrillation, (8 episodes) or ventricular tachycardia (5 episodes). No ineffective therapy from the device was delivered in any patients with right-sided implantation. Right-sided pectoral implants are feasible with the Medtronic Jewel active can ICD.
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Affiliation(s)
- G C Flaker
- University of Missouri Hospital, Division of Cardiology, Columbia, USA
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19
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Abstract
Lead systems that include an active pectoral shell reduce defibrillation thresholds and permit transvenous defibrillation in nearly all patients. A further improvement in defibrillation efficacy is desirable to allow for smaller pulse generators with a reduced maximum output. Accordingly, the purpose of this study was to compare defibrillation thresholds with multiple transvenous lead systems including those with an active pectoral shell to determine which system would optimize defibrillation energy requirements. This prospective study was performed on 21 consecutive patients. Each subject was evaluated with 3 lead configurations with the order of testing randomized. The configurations were a dual coil transvenous lead (lead), the distal right ventricular coil and pectoral pulse generator shell (unipolar), and all 3 components (triad). The right ventricular coil was the cathode for the first phase of the biphasic defibrillation waveform. Delivered energy at defibrillation threshold was 11.2 +/- 3.4 J for the lead configuration, 10.1 +/- 5.2 J for the unipolar configuration, and 7.8 +/- 3.6 J for the triad configuration (p <0.01). Leading edge voltage (p <0.01) and shock impedance (p <0.001) were also decreased for the triad configuration compared with the lead or unipolar configurations, whereas peak current was minimized with the unipolar configuration (p <0.01). We conclude that the combination of a dual coil, transvenous lead and an active pectoral shell reduces defibrillation energy requirements compared with either the lead alone or unipolar configuration. Moreover, the defibrillation thresholds were < or =15 J in all patients using the triad lead system.
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Affiliation(s)
- M R Gold
- Department of Medicine, University of Maryland School of Medicine, Baltimore, USA
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20
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Block M, Hammel D, Breithardt G. [Influence of waveform and configuration of electrodes on the defibrillation threshold of implantable cardioverter-defibrillators]. Herzschrittmacherther Elektrophysiol 1997; 8:15-31. [PMID: 19495674 DOI: 10.1007/bf03042474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/1996] [Accepted: 12/16/1996] [Indexed: 05/27/2023]
Abstract
The defibrillation threshold (DFT) is no threshold in the true sense. Between energy levels which defibrillate in all cases and energy levels which never defibrillate, a broad range of energies exists which might or might not defibrillate. Thus, the value of the DFT is dependant on the protocol used for its determination. Usually the DFT presents an energy at which the implantable cardioverter-defibrillator (ICD) will defibrillate successfully at a rate of approximately 75%. To achieve a 100% success rate the energy has to be programmed 15 J above the DFT or twice the DFT.Using DFT measurements the energy needed for internal defibrillation could be gradually reduced in the last years. Major break throughs have been the introduction of the biphasic defibrillation waveform and the use of pectorally implanted ICD shells as defibrillation electrodes. The shortening of the defibrillation impulse by the use of lower capacitances could not improve DFTs but allowed to construct ICDs of smaller volume. Addition of a superior vena cava electrode or a subcutaneous array electrode at the left lateral chest to the standard bipolar electrode system (right ventricle, pectoral ICD can) allowed for tri- and quadripolar lead configurations which reduced DFTs on average only slightly but reduced the standard deviation of DFTs significantly and thus helped to avoid high DFTs. Besides building smaller ICDs, reduction of DFTs and thus programming of lower defibrillation ICD energies allows for improved battery longevities and reduced capacitor charging times and thus a lower incidence of syncopes.
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Affiliation(s)
- M Block
- Medizinische Klinik und Poliklinik Innere Medizin C, Westfälische Wilhelms-Universität Münster, 48129, Münster
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Gold MR, Foster AH, Shorofsky SR. Effects of an active pectoral-pulse generator shell on defibrillation efficacy with a transvenous lead system. Am J Cardiol 1996; 78:540-3. [PMID: 8806339 DOI: 10.1016/s0002-9149(96)00361-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Transvenous lead systems have become routine for defibrillator implantation. A reduction of pulse generator size has made pectoral placement possible and enabled the pulse generator shell to become an active part of the defibrillation pathway. To directly assess the effect of the addition of an active generator on defibrillation thresholds to a transvenous lead system, we prospectively measured paired, randomized defibrillation thresholds (DFTs) in 21 patients undergoing defibrillator implantation. A dual coil lead (Endotak C, Cardiac Pacemakers, Inc., Guidant Corp., St. Paul, Minnesota) was used with the distal coil as the cathode for all shocks. The DFT was 8.4 +/- 3.2 J with the active shell, compared with 13.1 +/- 6.9 J with the lead alone (p < 0.01). This reduction was greatest in those patients with higher thresholds with the lead-alone configuration and resulted in DFT < or = 15 J with the active shell configuration in all patients. Shock impedance was reduced from 49 +/- 5 to 42 +/- 4 ohms (p < .001), but peak current at defibrillation threshold was unaffected by the addition of the active pectoral shell. We conclude that the addition of an active pectoral shell to a 2-coil transvenous lead system resulted in a marked reduction of defibrillation energy requirements. The uniformly low DFT ( < or = 15 J) observed suggests that an active pulse generator with a 25 J maximum output could be implanted in most patients while maintaining an adequate defibrillation safety margin.
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Affiliation(s)
- M R Gold
- Department of Medicine, University of Maryland, Baltimore, USA
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Pathways for Defibrillation Current. ACTA ACUST UNITED AC 1996. [DOI: 10.1007/978-1-4615-6345-7_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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