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Knops RE, El-Chami MF, Marquie C, Nordbeck P, Quast AFBE, Tilz RR, Brouwer TF, Lambiase PD, Cassidy CJ, Boersma LVA, Burke MC, Pepplinkhuizen S, de Veld JA, de Weger A, Bracke FALE, Manyam H, Probst V, Betts TR, Bijsterveld NR, Defaye P, Demming T, Elders J, Field DC, Ghani A, Golovchiner G, de Jong JSSG, Lewis N, Marijon E, Martin CA, Miller MA, Shaik NA, van der Stuijt W, Kuschyk J, Olde Nordkamp LRA, Arya A, Borger van der Burg AE, Boveda S, van Doorn DJ, Glikson M, Kaiser L, Maass AH, van Woerkens LJPM, Zaidi A, Wilde AAM, Smeding L. Predictive value of the PRAETORIAN score for defibrillation test success in patients with subcutaneous ICD: A subanalysis of the PRAETORIAN-DFT trial. Heart Rhythm 2024; 21:836-844. [PMID: 38336193 DOI: 10.1016/j.hrthm.2024.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/24/2024] [Accepted: 02/03/2024] [Indexed: 02/12/2024]
Abstract
BACKGROUND The PRAETORIAN score estimates the risk of failure of subcutaneous implantable cardioverter-defibrillator (S-ICD) therapy by using generator and lead positioning on bidirectional chest radiographs. The PRospective randomized compArative trial of subcutanEous implanTable cardiOverter-defibrillatoR ImplANtation with and without DeFibrillation Testing (PRAETORIAN-DFT) investigates whether PRAETORIAN score calculation is noninferior to defibrillation testing (DFT) with regard to first shock efficacy in spontaneous events. OBJECTIVE This prespecified subanalysis assessed the predictive value of the PRAETORIAN score for defibrillation success in induced ventricular arrhythmias. METHODS This multicenter investigator-initiated trial randomized 965 patients between DFT and PRAETORIAN score calculation after de novo S-ICD implantation. Successful DFT was defined as conversion of induced ventricular arrhythmia in <5 seconds from shock delivery within 2 attempts. Bidirectional chest radiographs were obtained after implantation. The predictive value of the PRAETORIAN score for DFT success was calculated for patients in the DFT arm. RESULTS In total, 482 patients were randomized to undergo DFT. Of these patients, 457 (95%) underwent DFT according to protocol, of whom 445 (97%) had successful DFT and 12 (3%) had failed DFT. A PRAETORIAN score of ≥90 had a positive predictive value of 25% for failed DFT, and a PRAETORIAN score of <90 had a negative predictive value of 99% for successful DFT. A PRAETORIAN score of ≥90 was the strongest independent predictor for failed DFT (odds ratio 33.77; confidence interval 6.13-279.95; P < .001). CONCLUSION A PRAETORIAN score of <90 serves as a reliable indicator for DFT success in patients with S-ICD, and a PRAETORIAN score of ≥90 is a strong predictor for DFT failure.
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Affiliation(s)
- Reinoud E Knops
- Amsterdam UMC location University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam Cardiovascular Sciences Heart Failure & Arrhythmias, Amsterdam, The Netherlands.
| | - Mikhael F El-Chami
- Division of Cardiology Section of Electrophysiology, Emory University, Atlanta, Georgia
| | | | - Peter Nordbeck
- Department of Internal Medicine I, University and University Hospital Würzburg, Würzburg, Germany
| | - Anne-Floor B E Quast
- Amsterdam UMC location University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam Cardiovascular Sciences Heart Failure & Arrhythmias, Amsterdam, The Netherlands
| | - Roland R Tilz
- Department of Rhythmology, University Heart Center Lübeck, University Hospital Schleswig-Holstein, Lübeck, Germany
| | - Tom F Brouwer
- Amsterdam UMC location University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam Cardiovascular Sciences Heart Failure & Arrhythmias, Amsterdam, The Netherlands
| | - Pier D Lambiase
- Office of the Director of Clinical Electrophysiology Research and Lead for Inherited Arrhythmia Specialist Services, University College London and Barts Heart Centre, London, United Kingdom
| | - Christopher J Cassidy
- Lancashire Cardiac Centre, Blackpool Teaching Hospitals NHS Trust, Blackpool, United Kingdom
| | - Lucas V A Boersma
- Amsterdam UMC location University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam Cardiovascular Sciences Heart Failure & Arrhythmias, Amsterdam, The Netherlands; Department of Cardiology, St. Antonius Hospital, Nieuwegein, The Netherlands
| | | | - Shari Pepplinkhuizen
- Amsterdam UMC location University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam Cardiovascular Sciences Heart Failure & Arrhythmias, Amsterdam, The Netherlands
| | - Jolien A de Veld
- Amsterdam UMC location University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam Cardiovascular Sciences Heart Failure & Arrhythmias, Amsterdam, The Netherlands
| | - Anouk de Weger
- Amsterdam UMC location University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam Cardiovascular Sciences Heart Failure & Arrhythmias, Amsterdam, The Netherlands
| | - Frank A L E Bracke
- Department of Electrophysiology, Catharina Hospital Eindhoven, Eindhoven, The Netherlands
| | - Harish Manyam
- Department of Cardiology Erlanger Health System, University of Tennessee, Chattanooga, Tennessee
| | - Vincent Probst
- Service de Cardiologie, L'institut du thorax, CHU Nantes, Nantes, France
| | - Timothy R Betts
- Oxford Biomedical Research Centre, Oxford University Hospitals NHS Trust, Oxford, United Kingdom
| | - Nick R Bijsterveld
- Amsterdam UMC location University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam Cardiovascular Sciences Heart Failure & Arrhythmias, Amsterdam, The Netherlands; Department of Cardiology, Flevoziekenhuis, Almere, The Netherlands
| | - Pascal Defaye
- Service de Cardiologie, Centre hospitalier universitaire, Grenoble, France
| | - Thomas Demming
- Department of Internal Medicine III, Cardiology, Angiology, and Critical Care, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Jan Elders
- Department of Cardiology, Canisius Wilhelminahospital, Nijmegen, The Netherlands
| | - Duncan C Field
- Cardiology, Essex Cardiothoracic Centre, Mid and South Essex NHS Foundation Trust, Basildon, United Kingdom
| | - Abdul Ghani
- Department of Cardiology, Isala Heart Centre, Zwolle, The Netherlands
| | | | | | - Nigel Lewis
- Department of Cardiology, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom
| | - Eloi Marijon
- Division of Cardiology, European Georges Pompidou Hospital, Paris, France
| | - Claire A Martin
- Department of Cardiology, Royal Papworth Hospital, Cambridge, United Kingdom
| | - Marc A Miller
- Icahn School of Medicine at Mount Sinai, Mount Sinai Hospital, New York, New York
| | - Naushad A Shaik
- Department of Cardiac Electrophysiology, Advent Health Orlando, Orlando, Florida
| | - Willeke van der Stuijt
- Amsterdam UMC location University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam Cardiovascular Sciences Heart Failure & Arrhythmias, Amsterdam, The Netherlands
| | - Jürgen Kuschyk
- First Department of Medicine, University Medical Center Mannheim, Mannheim, Germany; First Department of Medicine-Cardiology, University Medical Center Mannheim, and the German Center for Cardiovascular Research Partner Site Heidelberg-Mannheim, Mannheim, Germany
| | - Louise R A Olde Nordkamp
- Amsterdam UMC location University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam Cardiovascular Sciences Heart Failure & Arrhythmias, Amsterdam, The Netherlands
| | - Anita Arya
- New Cross Hospital, Heart and Lung Centre, Division of Electrophysiology and Devices, Royal Wolverhampton NHS Trust, Wolverhampton, United Kingdom
| | | | - Serge Boveda
- Heart Rhythm Department, Clinique Pasteur, Toulouse, France
| | - Dirk J van Doorn
- Department of Cardiology, Spaarne Gasthuis, Hoofddorp, The Netherlands
| | - Michael Glikson
- Jesselson Integrated Heart Center, Shaare Zedek Medical Center, Jerusalem, Israel
| | - Lukas Kaiser
- Department of Cardiology and Critical Care Medicine, Asklepios Klinik St. Georg, Hamburg, Germany
| | - Alexander H Maass
- Department of Cardiology, University Medical Center Groningen, Groningen, The Netherlands
| | | | - Amir Zaidi
- Manchester Heart Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, United Kingdom
| | - Arthur A M Wilde
- Amsterdam UMC location University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam Cardiovascular Sciences Heart Failure & Arrhythmias, Amsterdam, The Netherlands
| | - Lonneke Smeding
- Amsterdam UMC location University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam Cardiovascular Sciences Heart Failure & Arrhythmias, Amsterdam, The Netherlands
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Vanneman MW. Anesthetic Considerations for Percutaneous Coronary Intervention for Chronic Total Occlusions-A Narrative Review. J Cardiothorac Vasc Anesth 2021; 36:2132-2142. [PMID: 34493436 DOI: 10.1053/j.jvca.2021.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 07/18/2021] [Accepted: 08/01/2021] [Indexed: 11/11/2022]
Abstract
Advancing stent technology has enabled interventional cardiologists to perform percutaneous coronary intervention (PCI) to open chronic total occlusions (CTOs). Because PCI for CTOs improve patient anginal symptoms and quality of life, these procedures have been increasing over the past decade. Compared to standard PCI, these procedures are technically more difficult, with prolonged procedure time and increased risk of complications. Accordingly, anesthesiologists are increasingly being asked to provide sedation for these patients in the cardiac catheterization suite. In CTO PCI, anesthesiologists are more likely to encounter complications such as coronary artery perforation, malignant arrhythmias, non-target vessel ischemia, bleeding and shock. Additionally, CTO PCI may be supported by mechanical circulatory support devices. Understanding the procedural techniques of these complex PCI procedures is important to enable optimal anesthetic care in these patients. This narrative review discusses the pathophysiology, risks, benefits, procedural steps, and main anesthetic considerations for patients undergoing CTO PCI. Despite a growing body of literature, future research is still required to elucidate optimal anesthetic and mechanical support strategies in patients undergoing CTO PCI.
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Affiliation(s)
- Matthew W Vanneman
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA.
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3
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Sanchez DJ, Lozano IF. Implantable cardioverter-defibrillator in hypertrophic cardiomyopathy. Glob Cardiol Sci Pract 2018; 2018:31. [PMID: 30393643 PMCID: PMC6209444 DOI: 10.21542/gcsp.2018.31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Sudden cardiac death (SCD) is the most devastating complication in hypertrophic cardiomyopathy (HCM). The implantable cardioverter–defibrillator (ICD) has proven to be effective in SCD prevention in several clinical scenarios. In HCM population, it has demonstrated to successfully abort life-threatening ventricular arrhythmias despite the extreme morphology characteristic of HCM, often with massive degrees of left ventricular hypertrophy and/or LV outflow tract obstruction. Studies showed a high rate of appropriate intervention in secondary prevention and in primary prevention of patients considered at high risk. This appropriate intervention rate is even more significant considering the young and otherwise healthy patients that compose HCM population. Since SCD incidence in HCM is relatively low, optimal identification of patients at high risk is crucial. Classical strategy of risk stratification based on clinical risk factors has several limitations and has proven to overestimate risk. A new risk prediction model that provides individual 5-year estimated risk appears to be superior to traditional models based on bivariate risk factors. Perioperative complications seem to be similar to those related to the implant of other cardiac devices, while long-term complications have been traditionally in the spotlight. HCM patients are considered more vulnerable to ICD-related complications and inappropriate ICD therapy because of their young age at implant and increased prevalence of atrial fibrillation, but long-term follow-up data on ICD-related complications in general practice is limited. The subcutaneous implantable cardioverter defibrillator seems to be a safe and effective alternative in HCM, although long-term data are scarce.
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Phan K, Ha H, Kabunga P, Kilborn MJ, Toal E, Sy RW. Systematic Review of Defibrillation Threshold Testing at De Novo Implantation. Circ Arrhythm Electrophysiol 2016; 9:e003357. [DOI: 10.1161/circep.115.003357] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 03/14/2016] [Indexed: 11/16/2022]
Abstract
Background—
Recent results from the largest multicenter randomized trial (Shockless IMPLant Evaluation [SIMPLE]) on defibrillation threshold (DFT) testing suggest that while shock testing seems safe, it does not reduce the risk of failed shocks or prolong survival. A contemporary systematic review of DFT versus no-DFT testing at the time of implantable cardioverter–defibrillator implantation was performed to evaluate the current evidence and to assess the impact of the SIMPLE study.
Methods and Results—
Electronic searches were performed using 6 databases from their inception to March 2014. Relevant studies investigating implant DFT were identified. Data were extracted and analyzed according to predefined clinical end points. Predefined outcomes for interrogation were all-cause mortality, composite end point of implantable cardioverter–defibrillator efficacy (arrhythmic deaths and ineffective shocks), and composite safety end point (the sum of complications recorded at 30 days). Meta-analysis was performed including 13 studies and 9740 patients. No significant differences between DFT versus no-DFT cohorts were found in terms of all-cause mortality (risk ratio, 0.90; 95% confidence interval, 0.71–1.15;
P
=0.41), composite efficacy outcome (risk ratio, 1.24; 95% confidence interval, 0.65–3.37;
P
=0.51), and 30-day postimplant complications (risk ratio, 1.18; 95% confidence interval, 0.87–1.60;
P
=0.29). No significant difference was found in the trends observed when the results of the SIMPLE study were excluded or included.
Conclusions—
This systematic review of contemporary data suggests a modest average effect of DFT, if any, in terms of mortality, shock efficacy, or safety. Therefore, DFT testing should no longer be compulsory during de novo implantation. However, DFT testing may still be clinically relevant in specific patient populations.
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Affiliation(s)
- Kevin Phan
- From the Faculty of Medicine, Sydney Medical School (K.P., M.J.K., R.W.S.), Department of Cardiology, Westmead Clinical School (K.P.), and Department of Cardiology, Royal Prince Alfred Hospital (P.K., M.J.K., E.T., R.W.S.), University of Sydney, Sydney, Australia; and Faculty of Medicine, St. Vincent’s Clinical School, University of New South Wales, Sydney, Australia (H.H.)
| | - Hakeem Ha
- From the Faculty of Medicine, Sydney Medical School (K.P., M.J.K., R.W.S.), Department of Cardiology, Westmead Clinical School (K.P.), and Department of Cardiology, Royal Prince Alfred Hospital (P.K., M.J.K., E.T., R.W.S.), University of Sydney, Sydney, Australia; and Faculty of Medicine, St. Vincent’s Clinical School, University of New South Wales, Sydney, Australia (H.H.)
| | - Peter Kabunga
- From the Faculty of Medicine, Sydney Medical School (K.P., M.J.K., R.W.S.), Department of Cardiology, Westmead Clinical School (K.P.), and Department of Cardiology, Royal Prince Alfred Hospital (P.K., M.J.K., E.T., R.W.S.), University of Sydney, Sydney, Australia; and Faculty of Medicine, St. Vincent’s Clinical School, University of New South Wales, Sydney, Australia (H.H.)
| | - Michael J. Kilborn
- From the Faculty of Medicine, Sydney Medical School (K.P., M.J.K., R.W.S.), Department of Cardiology, Westmead Clinical School (K.P.), and Department of Cardiology, Royal Prince Alfred Hospital (P.K., M.J.K., E.T., R.W.S.), University of Sydney, Sydney, Australia; and Faculty of Medicine, St. Vincent’s Clinical School, University of New South Wales, Sydney, Australia (H.H.)
| | - Edward Toal
- From the Faculty of Medicine, Sydney Medical School (K.P., M.J.K., R.W.S.), Department of Cardiology, Westmead Clinical School (K.P.), and Department of Cardiology, Royal Prince Alfred Hospital (P.K., M.J.K., E.T., R.W.S.), University of Sydney, Sydney, Australia; and Faculty of Medicine, St. Vincent’s Clinical School, University of New South Wales, Sydney, Australia (H.H.)
| | - Raymond W. Sy
- From the Faculty of Medicine, Sydney Medical School (K.P., M.J.K., R.W.S.), Department of Cardiology, Westmead Clinical School (K.P.), and Department of Cardiology, Royal Prince Alfred Hospital (P.K., M.J.K., E.T., R.W.S.), University of Sydney, Sydney, Australia; and Faculty of Medicine, St. Vincent’s Clinical School, University of New South Wales, Sydney, Australia (H.H.)
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5
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Ohlow MA, Roos M, Lauer B, Geller JC. Incidence of ineffective safety margin testing (<10 J) and efficacy of routine subcutaneous array insertion during implantable cardioverter defibrillator implantation. Indian Pacing Electrophysiol J 2016; 16:47-52. [PMID: 27676160 PMCID: PMC5832618 DOI: 10.1016/j.ipej.2016.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 02/19/2016] [Indexed: 11/30/2022] Open
Abstract
The purpose of this study was to assess (1) the incidence of safety margin testing <10 J (SMT) and (2) the efficacy/safety of routinely adding a subcutaneous array (SQA) (Medtronic 6996SQ) for these patients. Patients with SMT smaller than a 10-J safety margin from maximum output were considered to have very high readings and underwent SQA insertion. These patients were compared with the rest of the patients who had acceptable SMT (≥10 J). A total of 616 patients underwent ICD implantation during the analysis period. Of those, 16 (2.6%) had SMT <10 J. By univariate analysis, younger age, and non-ischemic cardiomyopathy, were all significant predictors of SMT <10 J (p < 0.05). In all 16 cases, other methods to improve SMT prior to array insertion were attempted but failed for all patients: reversing shock polarity (n = 15), removing the superior vena cava coil (n = 14), reprogramming shock waveform (n = 9), and repositioning right ventricular lead (n = 9). Addition of the SQA successfully increased SMT to within safety margin for all patients (32 ± 2 versus 21 ± 3 J; p < 0.001). Follow-up (mean 48.1 ± 21 months) was available for all patients with SQA, only 2 cases with inappropriate shocks due to atrial fibrillation had to be noted. None of the patients experienced complications due to SQA implantation. SMT <10 J occur in about 2.6% of patients undergoing ICD implantation. SQA insertion corrects this problem without procedural/mid-term complications.
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Affiliation(s)
- Marc-Alexander Ohlow
- Department of Cardiology, Zentralklinik, Robert-Koch-Allee 9, 99437 Bad Berka, Germany.
| | - Marcus Roos
- Clinic for Electrophysiology, Heart Center, Salzburger Leite 1, 67616 Bad Neustadt, Germany
| | - Bernward Lauer
- Department of Cardiology, Zentralklinik, Robert-Koch-Allee 9, 99437 Bad Berka, Germany
| | - J Christoph Geller
- Department of Invasive Electrophysiology, Zentralklinik, Robert-Koch-Allee 9, 99437 Bad Berka, Germany
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Iijima K, Chinushi M, Saitoh O, Hasegawa K, Sonoda K, Yagihara N, Sato A, Izumi D, Watanabe H, Furushima H, Aizawa Y, Minamino T. Frequency characteristics and associations with the defibrillation threshold of ventricular fibrillation in patients with implantable cardioverter defibrillators. Intern Med 2015; 54:1175-82. [PMID: 25986253 DOI: 10.2169/internalmedicine.54.3113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE The dominant frequency (DF) in frequency analyses is considered to represent the objective cycle length and complexity of activation under conditions of ventricular fibrillation (VF). However, knowledge regarding the mechanisms determining the DF in human VF is limited. We studied the characteristics of the DF of human VF and relationship between DF and the defibrillation threshold. METHODS Seventy-two implantable cardioverter-defibrillator patients and 211 VF were studied. Using defibrillation tests, we performed a frequency analysis with fast Fourier transformation. The correlations between DF and clinical characteristics, including the defibrillation threshold, were assessed. RESULTS The mean DF of all induced VFs was 5.2±0.8 Hz. The patients were divided into two groups according to DF: the low-DF (DF <5.2 Hz, n=32) and high-DF (DF ≥5.2 Hz, n=40) groups. The frequency of structural heart disease was significantly higher in the low-DF group. In addition, the QRS duration, QT interval and effective refractory period of the right ventricle (RV-ERP) were significantly longer in the low-DF group. A multivariate analysis showed RV-ERP to be the only independent predictor of DF. Excluding patients receiving group III anti-arrhythmic drugs, which are known to have potent defibrillation threshold effects, the defibrillation threshold was significantly lower in the low-DF group (p=0.026). CONCLUSION We found that the DF of human VF is associated with underlying heart disease, the cardiac function, cardiac conduction, ventricular refractoriness and defibrillation threshold. Our findings may be useful for identifying and managing patients with a high defibrillation threshold.
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Affiliation(s)
- Kenichi Iijima
- Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Japan
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Mizukami K, Yokoshiki H, Mitsuyama H, Watanabe M, Tenma T, Matsui Y, Tsutsui H. Predictors of high defibrillation threshold in patients with implantable cardioverter-defibillator using a transvenous dual-coil lead. Circ J 2014; 79:77-84. [PMID: 25391259 DOI: 10.1253/circj.cj-14-0860] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Defibrillation testing (DT) is considered a standard procedure during implantable cardioverter-defibrillator (ICD) implantation. However, little is known about the factors that are significantly related to patients with high defibrillation threshold (DFT) using the present triad system. METHODS AND RESULTS We examined 286 consecutive patients who underwent ICD implantation with a transvenous dual-coil lead and DT from December 2000 to December 2011. We defined patients who required 25 J or more by the implanted device as the high DFT group, and those who required less than 25 J as the normal DFT group. For each patient, assessment parameters included underlying disease, comorbidities, NYHA functional class, drugs, and echocardiographic measures. The high DFT group consisted of 12 patients (4.2%). Multivariate analysis identified 3 independent predictors for high DFT: atrial fibrillation (odds ratio (OR) 4.85, 95% confidence interval (CI) 1.24-22.33, P=0.023), hypertension (OR 4.01, 95% CI 1.08-15.96, P=0.039), thickness of interventricular septum (IVS) >12 mm (OR 4.82, 95% CI 1.17-20.31, P=0.030). CONCLUSIONS Atrial fibrillation, hypertension and IVS hypertrophy were significantly associated with high DFT. Identification of such patients could help to lower the risk of complications with DT.
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Affiliation(s)
- Kazuya Mizukami
- Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine
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9
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Russo AM, Chung MK. Is Defibrillation Testing Necessary for Implantable Transvenous Defibrillators? Circ Arrhythm Electrophysiol 2014; 7:337-46. [DOI: 10.1161/circep.113.000371] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Andrea M. Russo
- From the Cooper Medical School of Rowan University, Camden, NJ (A.M.R.); and Cleveland Clinic Foundation, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (M.K.C.)
| | - Mina K. Chung
- From the Cooper Medical School of Rowan University, Camden, NJ (A.M.R.); and Cleveland Clinic Foundation, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, OH (M.K.C.)
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10
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How to Manage a High Defibrillation Threshold in ICD Patients: and Does it Really Matter? CURRENT TREATMENT OPTIONS IN CARDIOVASCULAR MEDICINE 2013; 15:497-505. [DOI: 10.1007/s11936-013-0244-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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11
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Chronic oral amiodarone but not dronedarone therapy increases ventricular defibrillation threshold during acute myocardial ischemia in a closed-chest animal model. J Cardiovasc Pharmacol 2012; 59:523-8. [PMID: 22330675 DOI: 10.1097/fjc.0b013e31824d89fe] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Dronedarone, a recently approved antiarrhythmic drug, has been shown to have fewer side effects than amiodarone, particularly with regard to thyroid and neurologic events. Since the effects of either drug on ventricular defibrillation threshold during ischemia are unknown, the aim of this study was to compare the effects of dronedarone and amiodarone on defibrillation efficacy during ischemia in a closed-chest animal model. Dronedarone (30 mg·kg·d) and amiodarone (20 mg·kg·d) were administered orally for 3 weeks to 19 and 21 pigs, respectively. A control group (no treatment) comprised 19 pigs. A 2-lead endovascular defibrillation system was used. Each biphasic shock was delivered after 8 seconds of ventricular fibrillation. A step-up/step-down protocol was used to calculate mean defibrillation threshold before and 10 minutes after coronary artery occlusion using an angioplasty balloon in the left descending artery. At basal state, defibrillation threshold did not differ between the control (20.8 ± 4.8 J), amiodarone (21.2 ± 2 J), and dronedarone (19.5 ± 3 J) groups. After ischemia, the amiodarone group had a significantly higher defibrillation threshold than the control group (29.6 ± 3 J vs. 21.8 ± 5 J, respectively; P = 0.015), but the dronedarone (22.8 ± 4 J) and control groups had similar defibrillation threshold values. These data indicate that oral dronedarone treatment, unlike oral amiodarone, does not affect defibrillation threshold during ischemia in pigs.
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12
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Incidence and clinical predictors of low defibrillation safety margin at time of implantable defibrillator implantation. J Interv Card Electrophysiol 2012; 34:93-100. [DOI: 10.1007/s10840-011-9648-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Accepted: 11/15/2011] [Indexed: 11/27/2022]
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13
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Quin EM, Cuoco FA, Forcina MS, Coker JB, Yoe RH, Spencer WH, Fernandes VL, Nielsen CD, Sturdivant JL, Leman RB, Wharton JM, Gold MR. Defibrillation thresholds in hypertrophic cardiomyopathy. J Cardiovasc Electrophysiol 2010; 22:569-72. [PMID: 21091965 DOI: 10.1111/j.1540-8167.2010.01943.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Defibrillation threshold (DFT) testing is performed in part to ensure an adequate safety margin for the termination of spontaneous ventricular arrhythmias. Left ventricular mass is a predictor of high DFTs, so patients with hypertrophic cardiomyopathy (HCM) are often considered to be at risk for increased defibrillation energy requirements. However, there are little prospective data addressing this issue. OBJECTIVE To assess DFTs in patients with HCM and evaluate the clinical predictors of elevated DFTs. METHODS Eighty-nine consecutive patients with HCM and 600 control patients with ischemic or nonischemic cardiomyopathy underwent a uniform modified step-down DFT testing protocol. DFT was compared between the control and HCM populations. Predictors of elevated DFT were evaluated in the HCM group. RESULTS There was no difference in DFT between HCM and control groups (10.4 ± 5.8 J vs 11.2 ± 5.6 J, respectively). Among patients with HCM, clinical parameters such as left ventricular ejection fraction, interventricular septal thickness, left ventricular mass, and QRS duration were not predictive of an elevated DFT. Only 3 patients (3.4%) with HCM had a DFT >20 J. CONCLUSION Patients with HCM do not have elevated DFTs as compared to more typical populations undergoing implantable cardioverter-defibrillator implant; high-energy devices or complex lead systems are not needed routinely in this population.
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Affiliation(s)
- Ernest M Quin
- Division of Cardiology, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
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ROBERTS BRETTD, HOOD ROBERTE, SABA MAGDIM, DICKFELD TIMMM, SALIARIS ANASTASIOSP, SHOROFSKY STEPHENR. Defibrillation Threshold Testing in Patients with Hypertrophic Cardiomyopathy. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2010; 33:1342-6. [DOI: 10.1111/j.1540-8159.2010.02843.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
Intraoperative ICD-testing is traditionally performed in many hospitals in order to ensure reliable sensing, detection, and defibrillation of induced ventricular fibrillation. The technical progress of defibrillators allows rapid detection and delivery of high energy shocks which defibrillates effectively in the vast majority all patients at implant. This review describes arguments pro and contra of systematic testing of the defibrillation threshold in all patients. Many reasons argue against testing in all patients: experimental considerations, patients' specific and nonspecific factors, e.g., underlying severity of cardiac disease, ischemia, and medication, as well as factors specific to the ICD system, e.g., implanted type and location of electrodes and active cans. Finally, the testing method is very important, since it bears the risk of false negative test results because the a priori probability of a positive test result is >95%. Therefore, data from prospective randomized studies are necessary in order to abandon the tradition of ICD-testing on an evidence-based background.
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Walcott GP, Melnick SB, Killingsworth CR, Ideker RE. Comparison of low-energy versus high-energy biphasic defibrillation shocks following prolonged ventricular fibrillation. PREHOSP EMERG CARE 2010; 14:62-70. [PMID: 19947869 DOI: 10.3109/10903120903349838] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Since the initial development of the defibrillator, there has been concern that, while delivery of a large electric shock would stop fibrillation, it would also cause damage to the heart. This concern has been raised again with the development of the biphasic defibrillator. OBJECTIVE To compare defibrillation efficacy, postshock cardiac function, and troponin I levels following 150-J and 360-J shocks. METHODS Nineteen swine were anesthetized with isoflurane and instrumented with pressure catheters in the left ventricle, aorta, and right atrium. The animals were fibrillated for 6 minutes, followed by defibrillation with either low-energy (n = 8) or high-energy (n = 11) shocks. After defibrillation, chest compressions were initiated and continued until return of spontaneous circulation (ROSC). Epinephrine, 0.01 mg/kg every 3 minutes, was given for arterial blood pressure < 50 mmHg. Hemodynamic parameters were recorded for four hours. Transthoracic echocardiography was performed and troponin I levels were measured at baseline and four hours following ventricular fibrillation (VF). RESULTS Survival rates at four hours were not different between the two groups (low-energy, 5 of 8; high-energy, 7 of 11). Results for arterial blood pressure, positive dP/dt (first derivative of pressure measured over time, a measure of left ventricular contractility), and negative dP/dt at the time of lowest arterial blood pressure (ABP) following ROSC were not different between the two groups (p = not significant [NS]), but were lower than at baseline. All hemodynamic measures returned to baseline by four hours. Ejection fractions, stroke volumes, and cardiac outputs were not different between the two groups at four hours. Troponin I levels at four hours were not different between the two groups (12 +/- 11 ng/mL versus 21 +/- 26 ng/mL, p = NS) but were higher at four hours than at baseline (19 +/- 19 ng/mL versus 0.8 +/- 0.5 ng/mL, p < 0.05, groups combined). CONCLUSION Biphasic 360-J shocks do not cause more cardiac damage than biphasic 150-J shocks in this animal model of prolonged VF and resuscitation.
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Affiliation(s)
- Gregory P Walcott
- Department of Medicine-Division of Cardiovascular Diseases, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.
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FAHEEM OSMAN, PADALA ARUN, KLUGER JEFFREY, ZWEIBEL STEVEN, CLYNE CHRISTOPHERA. Coronary Sinus Shocking Lead As Salvage In Patients with Advanced CHF and High Defibrillation Thresholds. Pacing Clin Electrophysiol 2010; 33:967-72. [DOI: 10.1111/j.1540-8159.2010.02726.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Nagai T, Kurita T, Satomi K, Noda T, Okamura H, Shimizu W, Suyama K, Aihara N, Kobayashi J, Kamakura S. QRS prolongation is associated with high defibrillation thresholds during cardioverter-defibrillator implantations in patients with hypertrophic cardiomyopathy. Circ J 2009; 73:1028-32. [PMID: 19359812 DOI: 10.1253/circj.cj-08-0744] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND Although high defibrillation threshold (DFT) is a major and unavoidable clinical problem after implantation of an implantable cardioverter defibrillator (ICD), little is known about the cause and management of a high DFT in patients with hypertrophic cardiomyopathy (HCM). The purpose of this study was to assess the predictors of a high DFT in patients with HCM. METHODS AND RESULTS Twenty-three patients with non-dilated HCM who underwent ICD implantation were included. The DFT at the time of the device implantation was measured in all patients. The patients were divided into 2 groups, a high DFT group (DFT >or=15J, n=13) and a low DFT group (DFT <15J, n=10); and their baseline characteristics were compared. The QRS duration was longer in the high than in the low DFT group (128 +/-31 vs 103 +/-12 ms, respectively; P=0.02). QRS duration, left ventricular (LV) end-systolic diameter, and LV ejection fraction were significant predictors of DFT in univariate analysis. However, in multivariate analysis, the only factor significantly associated with DFT was QRS duration (P=0.002). CONCLUSIONS QRS duration is the most consistent predictor of a high DFT in HCM patients undergoing ICD implantation.
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Affiliation(s)
- Takayuki Nagai
- Division of Cardiology, Department of Internal Medicine, National Cardiovascular Center, Suita, Japan
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Ripplinger CM, Li W, Hadley J, Chen J, Rothenberg F, Lombardi R, Wickline SA, Marian AJ, Efimov IR. Enhanced transmural fiber rotation and connexin 43 heterogeneity are associated with an increased upper limit of vulnerability in a transgenic rabbit model of human hypertrophic cardiomyopathy. Circ Res 2007; 101:1049-57. [PMID: 17885214 PMCID: PMC2366809 DOI: 10.1161/circresaha.107.161240] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Human hypertrophic cardiomyopathy, characterized by cardiac hypertrophy and myocyte disarray, is the most common cause of sudden cardiac death in the young. Hypertrophic cardiomyopathy is often caused by mutations in sarcomeric genes. We sought to determine arrhythmia propensity and underlying mechanisms contributing to arrhythmia in a transgenic (TG) rabbit model (beta-myosin heavy chain-Q403) of human hypertrophic cardiomyopathy. Langendorff-perfused hearts from TG (n=6) and wild-type (WT) rabbits (n=6) were optically mapped. The upper and lower limits of vulnerability, action potential duration (APD) restitution, and conduction velocity were measured. The transmural fiber angle shift was determined using diffusion tensor MRI. The transmural distribution of connexin 43 was quantified with immunohistochemistry. The upper limit of vulnerability was significantly increased in TG versus WT hearts (13.3+/-2.1 versus 7.4+/-2.3 V/cm; P=3.2e(-5)), whereas the lower limits of vulnerability were similar. APD restitution, conduction velocities, and anisotropy were also similar. Left ventricular transmural fiber rotation was significantly higher in TG versus WT hearts (95.6+/-10.9 degrees versus 79.2+/-7.8 degrees; P=0.039). The connexin 43 density was significantly increased in the mid-myocardium of TG hearts compared with WT (5.46+/-2.44% versus 2.68+/-0.77%; P=0.024), and similar densities were observed in the endo- and epicardium. Because a nearly 2-fold increase in upper limit of vulnerability was observed in the TG hearts without significant changes in APD restitution, conduction velocity, or the anisotropy ratio, we conclude that structural remodeling may underlie the elevated upper limit of vulnerability in human hypertrophic cardiomyopathy.
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MESH Headings
- Action Potentials/physiology
- Animals
- Animals, Genetically Modified
- Arrhythmias, Cardiac/diagnostic imaging
- Arrhythmias, Cardiac/pathology
- Arrhythmias, Cardiac/physiopathology
- Cardiomyopathy, Hypertrophic/diagnostic imaging
- Cardiomyopathy, Hypertrophic/pathology
- Cardiomyopathy, Hypertrophic/physiopathology
- Connexin 43/genetics
- Connexin 43/metabolism
- Diffusion Magnetic Resonance Imaging
- Disease Models, Animal
- Echocardiography
- Female
- Genetic Heterogeneity
- Immunohistochemistry
- Male
- Myocardial Contraction/physiology
- Myocardium/metabolism
- Myocytes, Cardiac/pathology
- Myocytes, Cardiac/physiology
- Rabbits
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Affiliation(s)
- Crystal M Ripplinger
- Department of Biomedical Engineering, Washington University, St Louis, MO 63130, USA
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20
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Swerdlow CD, Russo AM, Degroot PJ. The dilemma of ICD implant testing. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2007; 30:675-700. [PMID: 17461879 DOI: 10.1111/j.1540-8159.2007.00730.x] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ventricular fibrillation (VF) has been induced at implantable cardioverter defibrillator (ICD) implant to ensure reliable sensing, detection, and defibrillation. Despite its risks, the value was self-evident for early ICDs: failure of defibrillation was common, recipients had a high risk of ventricular tachycardia (VT) or VF, and the only therapy for rapid VT or VF was a shock. Today, failure of defibrillation is rare, the risk of VT/VF is lower in some recipients, antitachycardia pacing is applied for fast VT, and vulnerability testing permits assessment of defibrillation efficacy without inducing VF in most patients. This review reappraises ICD implant testing. At implant, defibrillation success is influenced by both predictable and unpredictable factors, including those related to the patient, ICD system, drugs, and complications. For left pectoral implants of high-output ICDs, the probability of passing a 10 J safety margin is approximately 95%, the probability that a maximum output shock will defibrillate is approximately 99%, and the incidence of system revision based on testing is < or = 5%. Bayes' Theorem predicts that implant testing identifies < or = 50% of patients at high risk for unsuccessful defibrillation. Most patients who fail implant criteria have false negative tests and may undergo unnecessary revision of their ICD systems. The first-shock success rate for spontaneous VT/VF ranges from 83% to 93%, lower than that for induced VF. Thus, shocks for spontaneous VT/VF fail for reasons that are not evaluated at implant. Whether system revision based on implant testing improves this success rate is unknown. The risks of implant testing include those related to VF and those related to shocks alone. The former may be due to circulatory arrest alone or the combination of circulatory arrest and shocks. Vulnerability testing reduces risks related to VF, but not those related to shocks. Mortality from implant testing probably is 0.1-0.2%. Overall, VF should be induced to assess sensing in approximately 5% of ICD recipients. Defibrillation or vulnerability testing is indicated in 20-40% of recipients who can be identified as having a higher-than-usual probability of an inadequate defibrillation safety margin based on patient-specific factors. However, implant testing is too risky in approximately 5% of recipients and may not be worth the risks in 10-30%. In 25-50% of ICD recipients, testing cannot be identified as either critical or contraindicated.
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Affiliation(s)
- Charles D Swerdlow
- Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, and the David Geffen School of Medicine, UCLA, Los Angeles, California, USA.
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Turakhia MP, Varosy PD, Lee K, Tseng ZH, Lee R, Badhwar N, Scheinman M, Lee BK, Olgin JE. Impact of Renal Function on Survival in Patients with Implantable Cardioverter-Defibrillators. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2007; 30:377-84. [PMID: 17367357 DOI: 10.1111/j.1540-8159.2007.00678.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Although chronic renal insufficiency (CRI) is associated with increased cardiac and noncardiac mortality, there is limited data on the relationship between CRI and survival in patients with implantable cardioverter-defibrillators (ICDs), particularly across a wide range of renal function. METHODS We studied 507 consecutive patients receiving first-time ICDs from 1993-2003 at a single center. Preimplant serum creatinine measurements were used to determine glomerular filtration rate (GFR) and stage of chronic kidney disease (CKD). The primary outcome was time to death. RESULTS During a mean follow-up of 4 years, all-cause mortality through completion of follow-up increased stepwise by GFR stage (I: 16%, II: 20%, III: 35%; IV: 40%; V: 50%; P < 0.001 for trend). After multivariate adjustment, CRI was independently associated with death (HR = 1.7, P = 0.02), as were a serum creatinine >or=2.0 mg/dL (HR 2.5, P = 0.003) and the presence of end-stage renal disease (HR 6.8; P < 0.001). For every 10-unit decrease in GFR, the adjusted hazard of death increased 12% (P = 0.04). CONCLUSION The presence of CRI prior to implant is independently associated with increased mortality in patients receiving ICDs. The risk is proportional to the degree of renal dysfunction and is apparent even when GFR is only mildly reduced. Differences in mortality are observed within the first year of implant, and patients on dialysis are at highest risk. Because randomized trials of ICDs have not included large numbers of patients with moderate or severe renal disease, our findings may have important implications in prognosis and case selection of patients who otherwise meet current indications for ICD implantation.
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Affiliation(s)
- Mintu P Turakhia
- Cardiac Electrophysiology, Department of Medicine, University of California, San Francisco, California 94143-1354, USA
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Leong-Sit P, Gula LJ, Diamantouros P, Krahn AD, Skanes AC, Yee R, Klein GJ. Effect of defibrillation testing on management during implantable cardioverter-defibrillator implantation. Am Heart J 2006; 152:1104-8. [PMID: 17161062 DOI: 10.1016/j.ahj.2006.06.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Accepted: 06/07/2006] [Indexed: 11/27/2022]
Abstract
BACKGROUND Verification of defibrillation efficacy by defibrillation threshold (DFT) testing during implantable cardioverter-defibrillator implantation is the current standard. Generally, defibrillation of ventricular fibrillation at 10 J below the maximum output of a device is felt to establish an adequate safety margin. Nonetheless, DFT testing adds to cost and carries some potential for morbidity, whereas its impact on outcomes in the modern era of defibrillator technology is unclear. We aimed to determine the frequency that DFT testing resulted in a change at device implant and to identify clinical and echocardiographic predictors of the need for DFT testing. METHODS We reviewed all implantable cardioverter-defibrillators that were implanted at the London Health Sciences Centre (Ontario, Canada) from June 1999 to August 2003 and used multivariate analysis to determine variables associated with DFT test failures and elevated DFT values. When a defibrillation failure was not observed, a lowest energy to defibrillate (LED) was recorded. RESULTS Among 168 implants, DFT testing was successful with a minimum 10-J safety margin in 152 (90%), whereas the remaining 16 required changes at device implant. In a multivariate analysis, use of amiodarone was independently associated with DFT failure (odds ratio, 4.6; 95% confidence interval, 1.2-17.0). Significantly higher mean DFT/LED values were observed among patients on amiodarone (1.36 J; P = .0041). Those with nonischemic cardiomyopathy had a higher mean DFT/LED compared with those with ischemic cardiomyopathy (1.44 J; P = .028). CONCLUSIONS Use of amiodarone is associated with a 4-fold increase in risk of DFT failure and subsequent need for changes at implant to achieve a safe threshold. Defibrillation threshold testing appears to be most useful for patients taking amiodarone.
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Affiliation(s)
- Peter Leong-Sit
- Division of Cardiology, University of Western Ontario, London, Ontario, Canada
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Mainigi SK, Cooper JM, Russo AM, Nayak HM, Lin D, Dixit S, Gerstenfeld EP, Hsia HH, Callans DJ, Marchlinski FE, Verdino RJ. Elevated defibrillation thresholds in patients undergoing biventricular defibrillator implantation: Incidence and predictors. Heart Rhythm 2006; 3:1010-6. [PMID: 16945792 DOI: 10.1016/j.hrthm.2006.05.028] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Accepted: 05/30/2006] [Indexed: 02/07/2023]
Abstract
BACKGROUND The biventricular implantable cardioverter-defibrillator (ICD) is an important therapy for select patients with severe heart failure. Given reported risk factors for elevated defibrillation thresholds (DFTs), patients undergoing biventricular ICD placement would be suspected of having a higher incidence of elevated DFT. OBJECTIVES The purpose of this study was to examine the clinical predictors and mortality risk of elevated DFTs in patients receiving a biventricular ICD. METHODS Characteristics of patients undergoing biventricular ICD placement with an elevated DFT were compared to those without an elevated DFT. RESULTS An elevated DFT was found in 14 (12%) of 121 patients. Mean QRS duration was 210 +/- 50 ms in the elevated DFT group and 171 +/- 36 ms in the normal DFT group (P = .01). Patients with a QRS duration >or=200 ms were more likely to have an elevated DFT than those with a duration <200 ms (odds ratio 13.4, 95% confidence interval 3.1-66.7, P <.01). No other clinical characteristics were associated with an elevated DFT. More than 90% of patients with an elevated DFT achieved an adequate safety margin through system modification or manipulation of their drug regimen. An elevated DFT did not have an impact on 2-year mortality. CONCLUSION Patients with a biventricular ICD had a 12% incidence of elevated DFT in our sequential patient cohort. QRS duration prior to biventricular ICD placement is the most powerful predictor of patients at risk for an elevated DFT. An elevated DFT does not have an impact on mortality, perhaps because of successful implementation of system modifications to ensure an adequate defibrillation safety margin.
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Affiliation(s)
- Sumeet K Mainigi
- Department of Medicine, Electrophysiology Section, Division of Cardiovascular Medicine, University of Pennsylvania School of Medicine, Philadelphia, 19104, USA
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Pires LA, Johnson KM. Intraoperative testing of the implantable cardioverter-defibrillator: how much is enough? J Cardiovasc Electrophysiol 2006; 17:140-5. [PMID: 16533250 DOI: 10.1111/j.1540-8167.2005.00294.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Defibrillation testing of the implantable cardioverter-defibrillator (ICD) is considered a standard and required practice at the time of implantation. How much testing, if any in some cases, should be performed, however, remains unknown. METHODS AND RESULTS Included in this retrospective analysis were 835 patients (77% men; age 65 +/- 13 years) who received transvenous ICDs between January 1996 and December 2003. One hundred twenty-nine (15.5%) had intraoperative defibrillation threshold (DFT) testing, 503 (60.2%) had limited defibrillation safety margin testing, and 203 (24.3%) had no defibrillation testing. We compared the outcome (success of ICD therapies against spontaneous VT/VF events and survival) of the three groups of patients, who in some respects had important clinical differences. The success of the first delivered shocks against VT/VF was similar for DFT (91%), safety margin testing (91%), and no-testing (92%) groups; and the second shocks terminated the remaining episodes in all three groups. Sudden-death-free survival rates were similar in the three groups, however, the overall long-term survival rate was significantly lower in the no-testing group (58%) than in the DFT (74%) and safety margin testing (69%) groups (P < 0.0005). Multivariate analysis found no strong predictors of sudden death, but there were several independent predictors of overall mortality including lack of ICD testing (HR: 2.031, CI: 1.253-3.290, P = 0.004). CONCLUSION In this select patient cohort, success of ICD therapies and sudden-death-free survival were similar in patients who had DFT, safety margin testing, and no testing, but overall survival was significantly lower in the no-testing group. Thus in the absence of prospective mortality data, a minimum of safety margin ICD testing should remain standard practice.
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Affiliation(s)
- Luis A Pires
- Heart Rhythm Center and the Division of Cardiology, Department of Medicine, St. John Hospital and Medical Center, Detroit, Michigan 48236, USA.
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Zima E, Gergely M, Soós P, Gellér LA, Nemes A, Acsády G, Merkely B. The Effect of Induction Method on Defibrillation Threshold and Ventricular Fibrillation Cycle Length. J Cardiovasc Electrophysiol 2006; 17:377-81. [PMID: 16643358 DOI: 10.1111/j.1540-8167.2006.00352.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Since no clinical data are available on the comparison of the "shock on T-wave" and "high frequency burst" ventricular fibrillation (VF) induction modes during defibrillation threshold (DFT) testing, we aimed to compare these two methods during implantable cardioverter defibrillator implantation. METHODS The DFT was determined with a step-down protocol using biphasic, anodal polarity (100%, 40%, 20% voltage control) shocks. Patients were randomized: VF was induced by 50 Hz burst in group B (n = 45) and T-wave shock in group T (n = 41). The DFT was defined as the lowest energy level that terminated VF; confirmed DFT (DFTc) was defined as the minimal energy level that consecutively terminated VF twice. Success rate of DFTc was calculated during an intraindividual test for the alternate induction method. RESULTS A total of 546 episodes of VF were induced: n = 278 (B) vs n = 268 (T). Incidence of VT during inductions was 9.9% (B) vs 2.7% (T), P < 0.05. Neither the DFT, 8.8 +/- 4.0 J (B) vs 9.7 +/- 4.2 J (T), nor the DFTc, 10.6 +/- 5.1 J (B) vs 10.8 +/- 4.2 J (T), proved to be significantly different. A significant correlation was found between VF cycle length (CL) and the concomitant DFT (r = 0.298, P < 0.05) in group T only. Subgroup analysis of patients under chronic class III antiarrhythmic treatment showed no increase of the DFT in either group and significantly lower incidence of VT induction in group T regardless of antiarrhythmic treatment. CONCLUSION The DFT and the VFCL proved to be independent of the VF induction method. The T-wave shock was more unlikely to induce VT during DFT testing. These results suggest that both methods are reliable in DFT determination, though T-wave shock application is a more reliable method for DFT testing.
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Affiliation(s)
- Endre Zima
- Cardiovascular Center, Department of Cardiovascular Surgery, Semmelweis University, 68 Városmajor Str., H-1122 Budapest, Hungary
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Rodríguez B, Li L, Eason JC, Efimov IR, Trayanova NA. Differences between left and right ventricular chamber geometry affect cardiac vulnerability to electric shocks. Circ Res 2005; 97:168-75. [PMID: 15976315 PMCID: PMC2925187 DOI: 10.1161/01.res.0000174429.00987.17] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although effects of shock strength and waveform on cardiac vulnerability to electric shocks have been extensively documented, the contribution of ventricular anatomy to shock-induced polarization and postshock propagation and thus, to shock outcome, has never been quantified; this is caused by lack of experimental methodology capable of mapping 3-D electrical activity. The goal of this study was to use optical imaging experiments and 3-D bidomain simulations to investigate the role of structural differences between left and right ventricles in vulnerability to electric shocks in rabbit hearts. The ventricles were paced apically, and uniform-field, truncated-exponential, monophasic shocks of reversed polarity were applied over a range of coupling intervals (CIs) in experiment and model. Experiments and simulations revealed that reversing the direction of externally-applied field (RV- or LV- shocks) alters the shape of the vulnerability area (VA), the 2-D grid encompassing episodes of arrhythmia induction. For RV- shocks, VA was nearly rectangular indicating little dependence of postshock arrhythmogenesis on CI. For LV- shocks, the probability of arrhythmia induction was higher for longer than for shorter CIs. The 3-D simulations demonstrated that these effects stem from the fact that reversal of field direction results in relocation of the main postshock excitable area from LV wall (RV- shocks) to septum (LV- shocks). Furthermore, the effect of septal (but not LV) excitable area in postshock propagation was found to strongly depend on preshock state. Knowledge regarding the location of the main postshock excitable area within the 3-D ventricular volume could be important for improving defibrillation efficacy.
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Russo AM, Sauer W, Gerstenfeld EP, Hsia HH, Lin D, Cooper JM, Dixit S, Verdino RJ, Nayak HM, Callans DJ, Patel V, Marchlinski FE. Defibrillation threshold testing: is it really necessary at the time of implantable cardioverter-defibrillator insertion? Heart Rhythm 2005; 2:456-61. [PMID: 15840466 DOI: 10.1016/j.hrthm.2005.01.015] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2004] [Accepted: 01/04/2005] [Indexed: 12/25/2022]
Abstract
OBJECTIVES The purpose of this study was to (1) determine how often implantable cardioverter-defibrillator (ICD) system modifications were needed to obtain an adequate safety margin for defibrillation, (2) identify how often and for what indications defibrillation threshold (DFT) testing was not performed, and (3) identify factors predicting the need for modification. BACKGROUND Ventricular fibrillation (VF) typically is induced at the time of ICD insertion. Although DFT testing often is minimized, a safety margin of 10 J has been utilized as a standard of care. However, current devices offer technology such as biphasic waveforms and high outputs, and the need for testing has been questioned. METHODS We reviewed the records of the last 1,139 patients undergoing initial ICD placement, generator replacement, or revision. RESULTS Seventy-one patients (6.2%) were identified as having an unacceptably high DFT (<10 J safety margin) requiring intervention, and some required >1 modification. Use of a high-output device alone was not enough to obtain an adequate DFT in 48% (34/71) of patients who required modifications (3% of the total population). No arrhythmia inductions were performed in 54 patients (4.7%) because of well-defined clinical conditions. Patients who required system modification had a lower ejection fraction, were younger, were less likely to have coronary artery disease, were more likely to be undergoing upgrade/generator replacement, and were more likely to be taking amiodarone. Long-term mortality was not different between the group of patients who required modification compared with those who did not (17% vs 20%, P = NS). CONCLUSIONS Routine VF induction and documentation of effective defibrillation still remains a reasonable part of ICD placement because an inadequate safety margin may occur in >6% of patients. The incidence of patients who were inappropriate for testing based on well-defined clinical conditions is small (<5%) in this unselected large series. Although some clinical features may predict the need for system modification, additional studies are needed to better define "acceptable efficacy" of ICDs in preventing sudden death prior to altering these standards in selected patients.
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Affiliation(s)
- Andrea M Russo
- University of Pennsylvania Health System, Philadelphia, Pennsylvania 19104, USA.
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Rashba EJ, Shorofsky SR, Brown T, Peters RW, Gold MR. Clinical predictors of atrial defibrillation thresholds with a dual-coil, active pectoral lead system. Heart Rhythm 2005; 2:49-54. [PMID: 15851265 DOI: 10.1016/j.hrthm.2004.10.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2004] [Accepted: 10/19/2004] [Indexed: 11/24/2022]
Abstract
OBJECTIVES The purpose of this study was to identify clinical predictors of atrial defibrillation thresholds (DFTs) with standard implantable cardioverter-defibrillator (ICD) leads. BACKGROUND Atrial defibrillation can be achieved with active pectoral, dual-coil transvenous ICD lead systems. If clinical predictors of atrial defibrillation efficacy with these lead systems were identified, they could be used to predict which patients may require more complex lead systems for atrial defibrillation, such as a coronary sinus electrode. METHODS This was a prospective study of 135 consecutive patients undergoing initial ICD implant for standard indications. The lead system evaluated was a transvenous defibrillation lead with coils in the superior vena cava (SVC) and right ventricular apex (RV), and a left pectoral pulse generator emulator (CAN). The shocking pathway was RV-->SVC+CAN. Atrial DFT was measured using a step-up protocol. Clinical and echocardiographic parameters were evaluated as predictors of atrial DFT and multiple linear regression was performed. RESULTS Mean atrial DFT was 4.6 +/- 3.8 J. Atrial DFT was < or =3 J in 70 patients (52%) and < or = 10 J in 97% of patients. The highest atrial DFT was 20 J (one patient). Left atrial size (r = 0.21, P = .01) and left ventricular end-diastolic diameter (r = 0.19, P = .02) were independent predictors of atrial DFT. However, these two predictors accounted for only 6% of the variability in atrial DFT. CONCLUSIONS Clinical parameters are of limited use in predicting atrial DFT with a dual-coil, active pectoral ICD lead system. Because the RV--> SVC + CAN shocking pathway provides reliable atrial and ventricular defibrillation, this configuration should be preferred for combined atrial and ventricular ICDs.
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Affiliation(s)
- Eric J Rashba
- Division of Cardiology, University of Maryland School of Medicine, Baltimore, 21201, USA.
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Roberts PR, Paisey JR, Betts TR, Allen S, Whitman T, Bonner M, Morgan JM. Comparison of coronary venous defibrillation with conventional transvenous internal defibrillation in man. J Interv Card Electrophysiol 2003; 8:65-70. [PMID: 12652180 DOI: 10.1023/a:1022300316980] [Citation(s) in RCA: 6] [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
OBJECTIVE Animal studies have shown that defibrillation in coronary veins is more effective than in the right ventricle. We aimed to assess the feasibility of placing defibrillation electrodes in the middle cardiac vein (MCV) in man and its impact on defibrillation requirements. METHODS A prospective randomised study conducted in a tertiary referral centre. 10 patients (9 male) undergoing ICD implantation (65 (12) yrs) for NASPE/BPEG indications were studied. Defibrillation thresholds (DFT) were measured, using a binary search and an external defibrillator after 10 seconds of ventricular fibrillation, for the following configurations in each patient (order of testing randomised): RV + MCV --> Can and RV --> SVC + Can. INTERVENTIONS A dual coil defibrillation electrode was placed transvenously in the right ventricle (RV) in the conventional manner. Using a guiding catheter a 3.2 Fr (67.5 mm length) electrode was placed transvenously in MCV. A test-can was placed subcutaneously in the left pectoral region. RESULTS Lead placement was possible in 8/10 pts. Time to perform a middle cardiac venogram and place the electrode was 21 (23) mins. No adverse events were observed. Defibrillation current was less (6.7 (2.7) A) with RV + MCV --> Can compared to the conventional RV --> SVC + Can configuration (8.9 (3.4) A, p = 0.03). There was no significant difference in defibrillation voltage or energy. However, shock impedance was higher in the former configuration (57 (10) v. 43 (6) Omega, p = 0.001). CONCLUSIONS In the majority of cases placement of a defibrillation lead in MCV is feasible. Defibrillation current requirements are 25% less when the shock is delivered using a MCV electrode.
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Affiliation(s)
- P R Roberts
- Southampton University Hospitals, Southampton, UK
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Gold MR. ICD therapy in the new millennium. Cardiol Clin 2000; 18:375-89. [PMID: 10849879 DOI: 10.1016/s0733-8651(05)70147-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Remarkable progress has been made in the 15 years since ICD therapy was approved for human use. The early "shock boxes" had almost no diagnostic capabilities and required thoracotomy for epicardial patch implantation with typical duration of hospitalization of about a week. Pulse-generator longevity was less than 2 years. Modern devices provide detailed information about the morphology and rate of electrocardiographic signals before, during, and after arrhythmia therapy. The down-sizing of pulse generators and improvements in lead design and shock waveforms allow the simplicity of defibrillator implantation to approach that of pacemakers, with defibrillation thresholds comparable with those initially observed with epicardial patches. Despite the marked reduction in size and increase in diagnostic capabilities, device longevity is now longer than 6 years. Routine outpatient ICD implantation is presently feasible and will increase in frequency if ongoing primary prevention trials prove beneficial. Further advances in lead technology and arrhythmia discrimination should increase the efficacy and reliability of therapy. Finally, devices have the capabilities to treat multiple problems in addition to life-threatening ventricular arrhythmias including atrial arrhythmias and congestive heart failure.
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Affiliation(s)
- M R Gold
- Department of Medicine, University of Maryland Medical Center, Baltimore, USA.
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Affiliation(s)
- S J Connolly
- McMaster University, Faculty of Health Sciences, Hamilton, Ontario, Canada.
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Wolfhard U, Knocks M, Sack S, Splittgerber FH, Fuchs JB, Günnicker M. [Not Available]. Herzschrittmacherther Elektrophysiol 1998; 9 Suppl 1:59-60. [PMID: 19484550 DOI: 10.1007/bf03042439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Affiliation(s)
- U Wolfhard
- Abteilung für Thorax- und Kardiovaskuläre Chirugie, Deutschland
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Gold MR, Khalighi K, Kavesh NG, Daly B, Peters RW, Shorofsky SR. Clinical predictors of transvenous biphasic defibrillation thresholds. Am J Cardiol 1997; 79:1623-7. [PMID: 9202352 DOI: 10.1016/s0002-9149(97)00210-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Transvenous lead systems have become routine for defibrillator placement. However, previous studies of clinical predictors of an adequate nonthoracotomy defibrillation threshold (DFT) evaluated monophasic waveforms or more complex lead systems, including subcutaneous patches. Accordingly, this study is a prospective evaluation of the predictors of an adequate biphasic DFT in 114 consecutive patients undergoing cardioverter-defibrillator implantation with a single transvenous lead. For each subject, 38 parameters were assessed, including standard demographic, electrocardiographic, echocardiographic, and radiographic measurements. An adequate DFT (< or =20 J) was achieved in 92% of patients. Multivariable analysis revealed 2 independent factors predictive of a high threshold: echocardiographic measurements of left ventricular dilation (odds ratio = 0.16, 95% confidence interval 0.05 to 0.53, p = 0.003) and body size (odds ratio = 0.36, 95% confidence interval 0.17 to 0.73; p = 0.005). No patient with a normal left ventricular end-diastolic dimension had a high DFT, whereas 14% (9 of 66) of those with left ventricular dilation had elevated thresholds. When the DFT cutoff was lowered to 15 J, as is necessary with some downsized pulse generators, an adequate threshold was observed in 84% of patients and the same 2 independent predictors of high thresholds were found. These results indicate that an adequate transvenous DFT can be predicted from simple clinical parameters.
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Affiliation(s)
- M R Gold
- Department of Medicine, University of Maryland Medical System, Baltimore 21201, USA
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