1351
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Scheinman MM, Keung E. The year in clinical cardiac electrophysiology. J Am Coll Cardiol 2007; 49:2061-9. [PMID: 17512364 DOI: 10.1016/j.jacc.2007.03.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Revised: 02/09/2007] [Accepted: 02/12/2007] [Indexed: 11/16/2022]
Affiliation(s)
- Melvin M Scheinman
- Section of Cardiac Electrophysiology, University of California San Francisco, San Francisco, California 94143, USA.
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1352
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Schuessler RB, Damiano RJ. Patient-specific surgical strategy for atrial fibrillation: promises and challenges. Heart Rhythm 2007; 4:1222-4. [PMID: 17765626 DOI: 10.1016/j.hrthm.2007.04.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2007] [Indexed: 10/23/2022]
Affiliation(s)
- Richard B Schuessler
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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1353
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Scherr D, Dalal D, Cheema A, Cheng A, Henrikson CA, Spragg D, Marine JE, Berger RD, Calkins H, Dong J. Automated detection and characterization of complex fractionated atrial electrograms in human left atrium during atrial fibrillation. Heart Rhythm 2007; 4:1013-20. [PMID: 17675074 DOI: 10.1016/j.hrthm.2007.04.021] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Accepted: 04/25/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND Complex fractionated atrial electrograms (CFAEs) have been reported as ablative targets for the treatment of atrial fibrillation (AF). However, the process of CFAE identification is highly dependent on the operator's judgment. OBJECTIVE It is the aim of the study to report our initial experience with a novel software algorithm designed to automatically detect CFAEs. METHODS Nineteen patients (6 female, 58 +/- 8 years) who underwent catheter ablation of paroxysmal (n = 11) or persistent (n = 8) AF were included in the study. During ongoing AF, 100 +/- 15 left atrial (LA) endocardial locations were sampled under the guidance of integrated electroanatomical mapping with computed tomographic images. Bipolar electrograms recorded throughout the LA were analyzed using custom software that allows for automated detection of CFAEs. Interval confidence level (ICL), defined as the number of intervals between consecutive CFAE complexes during 2.5-second recordings, was used to characterize CFAEs. The CFAE sites with an ICL >/=5 were considered as sites with highly repetitive CFAEs, which are thought to be potential ablation targets. For purposes of analysis, the LA was divided into 6 areas: pulmonary vein (PV) ostia, posterior wall, interatrial septum, roof, mitral annulus area, and appendage. RESULTS Among a total of 1,904 LA locations sampled in 19 patients, 1,644 (86%) were categorized as CFAE sites, whereas 260 (14%) were categorized as as non-CFAE sites. Thirty-four percent of all CFAE sites were identified as sites with highly repetitive CFAEs. Of these, 24% were located at the interatrial septum, 22% on the posterior wall, 20% at the PV ostia, 18% at the mitral annulus area, 14% on the roof, and 2.7% at the LA appendage. In all patients, highly repetitive CFAE sites were distributed in 4 or more areas of the LA. Persistent AF patients had more highly repetitive CFAE sites on the posterior wall than paroxysmal AF patients (30% +/- 7.3% vs 14% +/- 8.2%, P < .001). There was a strong trend toward more highly repetitive CFAE sites located at the PV ostia in patients with paroxysmal AF compared with persistent AF patients (24% +/- 13% vs 13% +/- 7.7%, P = .05). CONCLUSION With the use of custom software, CFAE complexes were identified in more than 80% of the LA endocardial locations. LA sites with highly repetitive CFAE sites were located predominately in the septum, posterior wall, and PV ostia. Patients with persistent AF had a different anatomical distribution pattern of highly repetitive CFAE sites from those with paroxysmal AF, with a greater prevalence of highly repetitive CFAEs located on the posterior wall. Further studies are warranted to determine the clinical significance of these findings.
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Affiliation(s)
- Daniel Scherr
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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1354
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Patel AA, White CM, Shah SA, Dale KM, Kluger J, Coleman CI. The relationship between statin use and atrial fibrillation. Curr Med Res Opin 2007; 23:1177-85. [PMID: 17519085 DOI: 10.1185/030079907x188026] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To investigate the relationship between statin therapy and the development of new-onset, recurrent, and postoperative atrial fibrillation (AF). RESEARCH DESIGN AND METHODS A systematic literature search was conducted through September 2006. Included studies were either randomized, controlled trials or observational studies with adjusted analyses using multivariate regression or covariate matching, compared patients receiving or not receiving a statin, and reported data on the incidence of AF. Weighted averages were reported as odds ratios with 95% confidence intervals (CIs) using a random-effects model. MAIN OUTCOME MEASURES The primary outcome measured was a combined endpoint of any AF type. Secondary outcomes included new-onset, recurrent, and postoperative AF. RESULTS Fourteen trials reporting the results of 15 unique analyses (n = 7402) were included. There was a 20% incidence rate for any AF with varying rates depending on AF type (new-onset [11%], recurrent [56%], recurrent after cardioversion [54%], postoperative [22%]). The use of a statin reduced the odds of developing any AF by 45% (odds ratio [OR] 0.55; 95% CI 0.43-0.70); Q statistic p = 0.001). Statins reduced the odds of developing new-onset AF by 32% (OR 0.68; 95% CI 0.51-0.90), recurrent AF by 57% (OR 0.43; 95% CI 0.24-0.79), recurrent AF after cardioversion by 42% (OR 0.58; 95% CI 0.32-1.05) and postoperative AF by 58% (OR 0.42; 95% CI 0.27-0.65). LIMITATIONS We considered studies that were observational in nature or only available in abstract form. Publication bias could not be ruled out. CONCLUSIONS Statin therapy was associated with a reduced odds of developing AF, thus providing evidence of the benefit of statins beyond the lipid-lowering activity.
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Affiliation(s)
- Aarti A Patel
- University of Connecticut School of Pharmacy, Storrs, CT, USA
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1355
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Themistoclakis S, Rossillo A, Bonso A, Raviele A. Intracardiac echocardiography for implantation of LAA occlusion devices: A further step toward the ICE era? Heart Rhythm 2007; 4:572-4. [PMID: 17467622 DOI: 10.1016/j.hrthm.2007.02.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Indexed: 10/23/2022]
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1356
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1357
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Husser D, Cannom DS, Bhandari AK, Stridh M, Sörnmo L, Olsson SB, Bollmann A. Electrocardiographic characteristics of fibrillatory waves in new-onset atrial fibrillation. ACTA ACUST UNITED AC 2007; 9:638-42. [PMID: 17470676 DOI: 10.1093/europace/eum074] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIMS In atrial fibrillation (AF), fibrillatory waves of surface electrocardiograms (ECG) vary among patients with respect to waveform and repetition rate. The purpose of this study was to (i) explore clinical determinants of new-onset AF and (ii) determine prognostic significance to predict initial treatment outcome of electrocardiographic fibrillatory wave characteristics in new-onset AF. METHODS AND RESULTS Twenty-five patients (15 male, mean age 69 +/- 16 years) with new-onset AF (median AF duration 8 days) were studied. Fibrillatory rate and exponential decay defined as decay of the curve that connects power maxima of dominant and harmonic frequency components were obtained by spatiotemporal QRST cancellation and time-frequency analysis of the index ECG (before treatment initiation). Baseline AF rate was 380 +/- 50 fibrillations per minute (fpm) (range 222-494); patients' age (beta = - 1.747, P = 0.003) and AF duration (beta = 0.726, P = 0.036) were independently related with fibrillatory rate. AF terminated within 24 h in seven patients, while it was persistent in the other 18 patients. Terminating AF had lower atrial rate (333 +/- 66 vs. 398 +/- 40 fpm, P = 0.005) and exponential decay (1.03 +/- 0.36 vs. 1.40 +/- 0.37, P = 0.041) than persisting AF. Multivariate analysis revealed fibrillatory rate to be the only independent predictor of AF termination or persistence (beta = 0.031, P = 0.031). Sensitivity and specificity for predicting AF termination were strongly related to fibrillatory rate (area under the curve = 0.817). Sensitivity and specificity were 89% and 71% for a fibrillatory rate of 355 fpm. CONCLUSIONS Fibrillatory rates vary substantially among patients to new-onset AF and are related to patients' age and AF duration. Lower fibrillatory rates indicate higher chances of spontaneous AF termination within 24 h.
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Affiliation(s)
- Daniela Husser
- Department of Cardiology, Good Samaritan Hospital and Harbor-UCLA Medical Center Los Angeles, CA, USA
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1358
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Ma CS, Liu X, Hu FL, Dong JZ, Liu XP, Wang XH, Long DY, Tang RB, Yu RH, Lu CS, Fang DP, Hao P, Liu XH. Catheter ablation of atrial fibrillation in patients with hyperthyroidism. J Interv Card Electrophysiol 2007; 18:137-42. [PMID: 17447127 DOI: 10.1007/s10840-007-9088-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Accepted: 02/12/2007] [Indexed: 10/23/2022]
Abstract
AIMS To study the clinical efficacy of catheter ablation for treating patients with hyperthyroidism-related atrial fibrillation (AF). MATERIALS AND METHODS The study involved 16 patients (12 males; age, 59.8 +/- 11.3 years) with hyperthyroidism-related AF, who had all been euthyroid for more than 3 months but still suffered from highly symptomatic and antiarrhythmia drug (AAD)-refractory AF. Circumferential pulmonary vein ablation (CPVA) guided by a 3-D mapping system was carried out to encircle the ipsilateral pulmonary veins (PVs) with a procedural endpoint of continuity of the circular lesions and PV isolation. Success was defined as the absence of any atrial tachyarrhythmia (ATa) off AADs beyond the first 3 months after the procedure. RESULTS CPVA was safely carried out in each of the 16 patients without any complications. PV isolation was achieved in all the treated PVs. After a mean follow-up of 15.8 +/- 11.8 (range, 6-55) months, 9 patients (56%) were free of ATa without any AADs beyond the first 3 months. AF relapsed in the remaining 7 patients, among whom 4 responded to AAD therapy and 3 were totally unresponsive. CONCLUSION For patients suffering hyperthyroidism-related AF, CPVA guided by a 3-D mapping system could represent one of the therapeutic options.
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Affiliation(s)
- Chang Sheng Ma
- Ward 2nd, Department of Cardiology, Beijing Anzhen Hospital, Capital University of Medical Sciences, Chaoyang District, Beijing, People's Republic of China.
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1359
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Affiliation(s)
- J Marcus Wharton
- Division of Cardiology, Medical University of South Carolina, Charleston, SC 29425, USA.
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1360
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Abstract
This review summarizes the mechanistic properties and the recent experience in the development of a new antiarrhythmic agent, RSD1235 (recently named vernakalant), for the acute conversion of atrial fibrillation to sinus rhythm. Atrial fibrillation is the most common sustained cardiac arrhythmia that is observed in clinical practice and is associated with increased morbidity and mortality, resulting from stroke and exacerbation of heart failure. At present, there is a lack of pharmacologic agents that are able to safely and effectively convert the arrhythmia back to sinus rhythm. Vernakalant has the electrophysiologic properties of a multiple ion channel blocker, developed using a novel approach to target potassium channels that are selectively present in human atria rather than ventricles, and using a rate-dependent blocking strategy for its additional sodium channel block. This paper reviews the mechanism of action of this drug, its performance in preclinical models of efficacy and human disease, and its actions on patients in the completed and published preregistration clinical trials for vernakalant. Overall, vernakalant converted 51.5% of patients who had < 7 days duration of atrial fibrillation and it did this without significantly more cardiovascular adverse events than placebo. Therefore, it must be considered as an important new agent for the treatment of this growing health problem.
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Affiliation(s)
- David Fedida
- University of British Columbia, Department of Anesthesiology, Vancouver, British Columbia, Canada
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1361
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López Menchaca R, Herrero Martínez JM, Suárez Fernández C. [Association of antiagregants: when and how]. Med Clin (Barc) 2007; 128:383-9. [PMID: 17386246 DOI: 10.1157/13099977] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aterothrombotic disease (coronary, cerebrovascular and peripheral artery disease) is the most common cause of mortality and disability in the world, antiaggregants representing one of its therapeutic and preventive pillars. We have drugs at present that act at different levels of platelet aggregation (COX inhibitors as well as inhibitors of phosphodiesterase, ADP P2Y12 receptor and IIb/IIIa receptor). We review here the efficacy and safety of the association of antiaggregants in most relevant clinical scenarios, including current clinical recommendations and an analysis of supportive evidence.
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1362
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Hsieh MH, Chen SA. Introduction to catheter ablation of atrial fibrillation: an overview. Heart Rhythm 2007; 4:S40-3. [PMID: 17336883 DOI: 10.1016/j.hrthm.2006.12.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Indexed: 11/24/2022]
Affiliation(s)
- Ming-Hsiung Hsieh
- Division of Cardiovascular Medicine, Department of Medicine, Taipei Medical University-Wan Fang Hospital, Taipei, Republic of China
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1363
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Cesario DA, Mahajan A, Shivkumar K. Lesion-forming technologies for catheter ablation of atrial fibrillation. Heart Rhythm 2007; 4:S44-50. [PMID: 17336884 DOI: 10.1016/j.hrthm.2006.12.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2006] [Indexed: 11/20/2022]
Affiliation(s)
- David A Cesario
- UCLA Cardiac Arrhythmia Center, Division of Cardiology, Department of Medicine, David Geffen School of Medicine at the UCLA, Los Angeles, California 90095-1679, USA
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1364
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Anderson ME. Multiple downstream proarrhythmic targets for calmodulin kinase II: Moving beyond an ion channel-centric focus. Cardiovasc Res 2007; 73:657-66. [PMID: 17254559 DOI: 10.1016/j.cardiores.2006.12.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Revised: 12/08/2006] [Accepted: 12/11/2006] [Indexed: 11/21/2022] Open
Abstract
The multifunctional Ca(2+) calmodulin-dependent protein kinase II (CaMKII) has emerged as a pro-arrhythmic signaling molecule. CaMKII can participate in arrhythmia signaling by effects on ion channel proteins, intracellular Ca(2+) uptake and release, regulation of cell death, and by activation of hypertrophic signaling pathways. The pleuripotent nature of CaMKII is reminiscent of another serine-threonine kinase, protein kinase A (PKA), which shares many of the same protein targets and is the downstream kinase most associated with beta-adrenergic receptor stimulation. The ability of CaMKII to localize and coordinate activity of multiple protein targets linked to Ca(2+) signaling set CaMKII apart from other "traditional" arrhythmia drug targets, such as ion channel proteins. This review will discuss some of the biology of CaMKII and focus on work that has been done on molecular, cellular, and whole animal models that together build a case for CaMKII as a pro-arrhythmic signal and as a potential therapeutic target for arrhythmias and structural heart disease.
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Affiliation(s)
- Mark E Anderson
- University of Iowa, Carver College of Medicine, Department of Internal Medicine, 200 Hawkins Drive, E315-A1 GH, Iowa City, IA 52242 USA.
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1365
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Affiliation(s)
- Peter Zimetbaum
- Division of Cardiology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
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1366
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Abstract
Atrial fibrillation is the most common arrhythmia that requires treatment, and although ablation is appropriate in many cases, anti-arrhythmic drug therapy remains the first and most appropriate therapy in most patients. Currently available antiarrhythmic drugs are limited by modest efficacy and significant toxicity. Cardiac toxicity relates to effects on the ventricle, especially in prolonging the QT interval and causing torsades de pointes. Amiodarone, an agent with multiple antiarrhythmic effects, is unique in its relative lack of pro-arrhythmia, although its non-cardiac toxicities limit its use. Some investigational agents are directed at multiple ion channels, or are designed to be analogs of amiodarone. The other line of investigation focuses on the antiarrhythmic action of agents that affect novel ion channel targets. Basic and early clinical studies show promise for drugs that provide atrial antiarrhythmic effects without ventricular pro-arrhythmia by affecting the atrium preferentially or selectively (inhibiting the I(TO) and I(Kur) currents, respectively). Future drugs may possess preferential effects on the remodeled atrium (and as such would be selective for patients with atrial fibrillation). It is hoped that efforts to develop new drugs, including those with preferential effects on the atrium, will provide therapy with greater efficacy and safety.
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Affiliation(s)
- Richard L Page
- Department of Internal Medicine (Cardiology Division), University of Washington School of Medicine, Seattle, Washington 98195-6422, USA.
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1367
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Mosca L, Banka CL, Benjamin EJ, Berra K, Bushnell C, Dolor RJ, Ganiats TG, Gomes AS, Gornik HL, Gracia C, Gulati M, Haan CK, Judelson DR, Keenan N, Kelepouris E, Michos ED, Newby LK, Oparil S, Ouyang P, Oz MC, Petitti D, Pinn VW, Redberg RF, Scott R, Sherif K, Smith SC, Sopko G, Steinhorn RH, Stone NJ, Taubert KA, Todd BA, Urbina E, Wenger NK. Evidence-Based Guidelines for Cardiovascular Disease Prevention in Women: 2007 Update. J Am Coll Cardiol 2007; 49:1230-50. [PMID: 17367675 DOI: 10.1016/j.jacc.2007.02.020] [Citation(s) in RCA: 244] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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1368
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Abstract
Atrial fibrillation is a marker for worse outcomes in patients with heart failure and requires careful, individualized management. Anticoagulation and rate control are important. Routine use of antiarrhythmic drug therapy for maintenance of sinus rhythm carries concerns of risk and limited efficacy. Catheter ablation for maintaining sinus rhythm is feasible for some patients, but further studies are needed to define the risks and benefits. A role remains for AV junction ablation and pacing, with consideration of biventricular pacing to prevent dyssynchrony induced by chronic right ventricular pacing. Ongoing trials will continue to define the risks and benefits as these therapies evolve.
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Affiliation(s)
- William G Stevenson
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
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1369
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Abstract
Although the surgical treatment of atrial fibrillation has become technically simpler and faster with the advent of new ablative technologies, the ultimate goal of treating large numbers of patients for lone AF remains elusive. The ideal procedure would be performed epicardially, on the beating heart, with minimal risk to and impact on the patient, a rapid recovery and high cure rates. As minimal access techniques improve along with device designs and our understanding of pathophysiology, the field continues to move toward this objective. This article provides a brief overview of the progress made, questions yet unanswered and possible future directions.
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Affiliation(s)
- Adam E Saltman
- Maimonides Medical Center, Division of CT Surgery, Brooklyn, New York 11219, USA.
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1370
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Mosca L, Banka CL, Benjamin EJ, Berra K, Bushnell C, Dolor RJ, Ganiats TG, Gomes AS, Gornik HL, Gracia C, Gulati M, Haan CK, Judelson DR, Keenan N, Kelepouris E, Michos ED, Newby LK, Oparil S, Ouyang P, Oz MC, Petitti D, Pinn VW, Redberg RF, Scott R, Sherif K, Smith SC, Sopko G, Steinhorn RH, Stone NJ, Taubert KA, Todd BA, Urbina E, Wenger NK. Evidence-based guidelines for cardiovascular disease prevention in women: 2007 update. Circulation 2007; 115:1481-501. [PMID: 17309915 DOI: 10.1161/circulationaha.107.181546] [Citation(s) in RCA: 524] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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1371
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Abstract
Patients on anticoagulants of the vitamin K antagonist type may sometimes be scheduled for invasive procedures or surgical operations. In order to minimize the risk of thromboembolism caused by the interruption of chronic anticoagulation for the procedure, temporary administration of anticoagulants with shorter half-lives is required (so-called bridging anticoagulation). The present review outlines the spectrum of risks during this period regarding both thromboembolism and major bleeding. Low molecular weight heparins may be considered the medication of choice for bridging anticoagulation, mainly for practical reasons. Since they require no coagulation monitoring or dose adjustment, outpatient treatment is feasible. Such heparins are not labelled for the indication of bridging anticoagulation. However, based on recent studies of large patient cohorts, evidence of their efficacy and safety is significantly more solid than for unfractionated heparin. A simple dosing scheme for low molecular weight heparins is given here and all requirements are discussed for safe guidance through episodes of bridging anticoagulation.
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Affiliation(s)
- S M Schellong
- Arbeitsbereich Angiologie, Medizinische Klinik III, Universitätsklinikum Carl Gustav Carus,Technische Universität Dresden, Fetscherstrasse 74, 01307 Dresden.
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1372
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Misawa Y, Saito T, Konishi H, Oki SI, Kaminishi Y, Sakano Y, Morita H, Aizawa K. Clinical experience with the Bicarbon heart valve prosthesis. J Cardiothorac Surg 2007; 2:8. [PMID: 17254363 PMCID: PMC1794238 DOI: 10.1186/1749-8090-2-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Accepted: 01/25/2007] [Indexed: 12/14/2022] Open
Abstract
Bacground We have previously reported mid-term results of a study, which ended in January 2000, on the Bicarbon valve. The study concluded that the valve showed excellent clinical results, associated with a low incidence of valve-related complications. In the present study, the same patients were prospectively followed for an additional 5 years. Methods Forty-four patients had aortic valve replacement (AVR), 48 had mitral valve replacement (MVR), and 13 had both aortic and mitral valve replacement (DVR). The mean age of the 105 patients was 61.2 ± 11.3 years. The mean follow-up was 6.1 ± 1.9 years with a cumulative follow-up of 616 patient-years. Results There were 5 early deaths (4.7%: 4 in the AVR group and 1 in the MVR group) and 21 late deaths (3.4%/patient-year: 5 valve related deaths and 16 valve unrelated deaths). Survival at 8 years was 75.2 ± 7.0% in the AVR group, 76.6 ± 6.2% in the MVR group, and 55.4 ± 16.1% in the DVR group. The linearized incidence of thrombo-embolic complications, hemorrhagic complications, and paravalvular leaks in all patients was 0.65 ± 1.48%, 0.81 ± 1.69%, and 0.16 ± 0.54%/patient-year respectively. No other complications were observed. Conclusion The Bicarbon prosthetic heart valve has shown excellent long-term clinical results, associated with a low incidence of valve-related complications.
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Affiliation(s)
- Yoshio Misawa
- Division of Cardiovascular Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, JAPAN
| | - Tsutomu Saito
- Division of Cardiovascular Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, JAPAN
| | - Hiroaki Konishi
- Division of Cardiovascular Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, JAPAN
| | - Shin-ichi Oki
- Division of Cardiovascular Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, JAPAN
| | - Yuichiro Kaminishi
- Division of Cardiovascular Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, JAPAN
| | - Yasuhito Sakano
- Division of Cardiovascular Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, JAPAN
| | - Hideki Morita
- Division of Cardiovascular Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, JAPAN
| | - Kei Aizawa
- Division of Cardiovascular Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, JAPAN
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1373
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1374
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Atrial Fibrillation and Flutter. CARDIOVASCULAR MEDICINE 2007. [DOI: 10.1007/978-1-84628-715-2_95] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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1375
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Tamargo J, Caballero R, Gómez R, Núñez L, Vaquero M, Delpón E. Lipid-lowering therapy with statins, a new approach to antiarrhythmic therapy. Pharmacol Ther 2006; 114:107-26. [PMID: 17287023 DOI: 10.1016/j.pharmthera.2006.12.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2006] [Accepted: 12/08/2006] [Indexed: 11/17/2022]
Abstract
Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (statins) are the most effective and best-tolerated drugs to treat elevated levels of low-density lipoprotein cholesterol (LDL-C). In addition, they exhibit other effects unrelated to their lipid lowering effects (pleiotropic actions). In recent years, experimental and clinical evidence demonstrates that statins exert antiarrhythmic properties, reducing the recurrences of supraventricular and life-threatening ventricular arrhythmias both in patients with and without coronary artery disease (CAD). Thus, statins may constitute a novel therapeutic approach to cardiac arrhythmias. This article reviews the antiarrhythmic properties of statins as well as the possible mechanisms involved, including the lowering of LDL-C levels, the improvement of endothelial dysfunction and autonomic function, the stabilization of the atherosclerotic plaques, the antioxidant, antiinflammatory, antithrombotic and cardioprotective properties and the modulation of transmembrane ion fluxes.
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Affiliation(s)
- Juan Tamargo
- Department of Pharmacology, School of Medicine, Universidad Complutense, Madrid, Spain.
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1376
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Abstract
Intravascular ventricular defibrillation and intravascular atrial defibrillation have many similarities. An important factor influencing the outcome of the shock is the potential gradient field created throughout the ventricles or the atria by the shock. A minimum potential gradient is required throughout the ventricles and probably the atria in order to defibrillate. The value of this minimum potential gradient is affected by several factors, including the duration, tilt, and number of phases of the waveform. For shock strengths near the defibrillation threshold, earliest activation following failed shocks arises in a region in which the potential gradient is low. The defibrillation threshold energy can be decreased by adding a third and even a fourth defibrillation electrode in regions where the shock potential gradient is low for the shock field created by the first two defibrillation electrodes and giving two sequential shocks, each through a different set of electrodes. However, the addition of more electrodes and sequential shocks complicates both the device and its implantation. Because patients are conscious when the atrial defibrillation shock is given, they experience pain during the shock, which is one of the main drawbacks of intravascular atrial defibrillation. Unfortunately, the pain threshold for defibrillation shocks is so low that a shock less than 1 J is uncomfortable and is not much less painful than shocks several times stronger. Therefore, even though electrode configurations exist that have lower atrial defibrillation threshold energy requirements than the atrial defibrillation threshold with standard defibrillation electrode configurations used in implantable cardioverter-defibrillators (ICDs) for ventricular defibrillation, they are not clinically practical because their shocks are almost as painful as with the standard ICD electrode configurations. Such electrode configurations would make the ICD more complicated, leading to greater difficulty and longer time required for implantation.
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Affiliation(s)
- Derek J. Dosdall
- Department of Biomedical Engineering, University of Alabama at Birmingham, Alabama, USA
| | - Raymond E. Ideker
- Department of Biomedical Engineering, University of Alabama at Birmingham, Alabama, USA
- Department of Medicine, University of Alabama at Birmingham, Alabama, USA
- Department of Physiology Birmingham, University of Alabama at Birmingham, Alabama, USA
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1377
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Berndt C, Lillig CH, Holmgren A. Thiol-based mechanisms of the thioredoxin and glutaredoxin systems: implications for diseases in the cardiovascular system. Am J Physiol Heart Circ Physiol 2006; 292:H1227-36. [PMID: 17172268 DOI: 10.1152/ajpheart.01162.2006] [Citation(s) in RCA: 246] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Reactive oxygen species (ROS) and the cellular thiol redox state are crucial mediators of multiple cell processes like growth, differentiation, and apoptosis. Excessive ROS production or oxidative stress is associated with several diseases, including cardiovascular disorders like ischemia-reperfusion. To prevent ROS-induced disorders, the heart is equipped with effective antioxidant systems. Key players in defense against oxidative stress are members of the thioredoxin-fold family of proteins. Of these, thioredoxins and glutaredoxins maintain a reduced intracellular redox state in mammalian cells by the reduction of protein thiols. The reversible oxidation of Cys-Gly-Pro-Cys or Cys-Pro(Ser)-Tyr-Cys active site cysteine residues is used in reversible electron transport. Thioredoxins and glutaredoxins belong to corresponding systems consisting of NADPH, thioredoxin reductase, and thioredoxin or NADPH, glutathione reductase, glutathione, and glutaredoxin, respectively. Thioredoxin as well as glutaredoxin activities appear to be very important for the progression and severity of several cardiovascular disorders. These proteins function not only as antioxidants, they inhibit or activate apoptotic signaling molecules like apoptosis signal-regulating kinase 1 and Ras or transcription factors like NF-kappaB. Thioredoxin activity is regulated by the endogenous inhibitor thioredoxin-binding protein 2 (TBP-2), indicating an important role of the balance between thioredoxin and TBP-2 levels in cardiovascular diseases. In this review, we will summarize cardioprotective effects of endogenous thioredoxin and glutaredoxin systems as well as the high potential in clinical applications of exogenously applied thioredoxin or glutaredoxin or the induction of endogenous thioredoxin and glutaredoxin systems.
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Affiliation(s)
- Carsten Berndt
- The Medical Nobel Inst for Biochemistry, Dept of Medical Biochemistry and Biophysics, Karolinska Inst, SE-17177 Stockholm, Sweden
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1378
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Abstract
The mechanisms of human atrial fibrillation (AF) are poorly understood. Experimental studies have demonstrated that cholinergic AF in the sheep heart is maintained by high-frequency reentrant sources (drivers) that result in a consistent left-to-right frequency gradient. More recently, clinical studies have confirmed the existence of a hierarchical organization in the rate of activation of different regions in the atria of patients with paroxysmal and chronic AF. Although maximal dominant-frequency sites were found to play a crucial role in the maintenance of AF in some patients, whether AF drivers in humans are focal or reentrant and whether changes in driver activity alter spatial frequency gradients are unclear. To test the hypothesis that localized functional reentry maintains AF in humans, we determined the effects of adenosine infusion on local dominant frequency at different sites of both atria. In patients with paroxysmal AF, adenosine infusion increases local dominant frequencies, particularly at the pulmonary vein-left atrial junction region, amplifying a left-to-right frequency gradient. In patients with chronic AF, dominant frequency is significantly higher than in patients with paroxysmal AF in all atrial regions surveyed, with the highest adenosine increase of frequencies outside the pulmonary vein region. Adenosine-induced driver acceleration is strongly suggestive of a reentrant mechanism in both groups of AF patients.
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Affiliation(s)
- Felipe Atienza
- Hospital General Universitario Gregorio Marañón, Madrid, Spain
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1379
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Abstract
Anticoagulation therapy in patients with atrial fibrillation is important. This review consists of three parts: chronic anticoagulation, anticoagulation for cardioversion, and a brief comment on anticoagulation around the time of left atrial radiofrequency ablation. The risk stratification scheme of the American College of Cardiology/American Heart Association/European Society of Cardiology (ACC/AHA/ESC) guidelines for chronic anticoagulation is briefly reviewed. Although there are several other similar schemes, they are not identical. The key point is the balance between benefit and risk. Some emerging controversies are outlined. Two specific questions explored are: is well-controlled hypertension a risk factor, and does paroxysmal atrial fibrillation confer the same risk as continuous atrial fibrillation? Differences in the risk of bleeding while taking a vitamin K antagonist noted in recent compared with older data are discussed. Risk of bleeding in the elderly and combined antithrombotic therapy with a vitamin K antagonist and an antiplatelet agent in high-risk patients are briefly discussed. Recent failures of studies attempting to find a suitable alternative to vitamin K antagonists are outlined. The treatment guidelines for anticoagulation for cardioversion are briefly reviewed. The risk of thromboembolism according to international normalized ratio and use of low-molecular-weight heparin as an alternative to warfarin are discussed. Anticoagulation before and after left atrial radiofrequency ablation is empirical, and long-term anticoagulation seems advisable for high risk patients at the present time. The two most pressing needs for further investigation are (1) clarification, simplification, and consolidated of risk stratification schemes and treatment recommendations and (2) discovery of alternatives to warfarin.
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Affiliation(s)
- D George Wyse
- Libin Cardiovascular Institute of Alberta, University of Calgary, and Calgary Health Region, Calgary, Alberta, Canada.
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1380
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Hylek EM, Henault LE, Evans-Molina C, Shea C, Regan S. Response to Letter by Testa et al. Stroke 2006. [DOI: 10.1161/01.str.0000248210.87666.c6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Elaine M. Hylek
- Department of Medicine, Research Unit-Section of General Internal Medicine, Boston University School of Medicine, Boston, Mass
| | - Lori E. Henault
- Department of Medicine, Research Unit-Section of General Internal Medicine, Boston University School of Medicine, Boston, Mass
| | | | - Carol Shea
- Department of Medicine, Massachusetts General Hospital, Boston, Mass
| | - Susan Regan
- Department of Medicine, Massachusetts General Hospital, Boston, Mass
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1381
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Abstract
Atrial fibrillation is associated with substantial morbidity and mortality. Pooled data from trials comparing antithrombotic treatment with placebo have shown that warfarin reduces the risk of stroke by 62%, and that aspirin alone reduces the risk by 22%. Overall, in high-risk patients, warfarin is superior to aspirin in preventing strokes, with a relative risk reduction of 36%. Ximelagatran, an oral direct thrombin inhibitor, was found to be as efficient as vitamin K antagonist drugs in the prevention of embolic events, but has been recently withdrawn because of abnormal liver function tests. The ACTIVE-W (Atrial Fibrillation Clopidogrel Trial with Irbesartan for Prevention of Vascular Events) study has demonstrated that warfarin is superior to platelet therapy (clopidogrel plus aspirin) in the prevention af embolic events. Idraparinux, a Factor Xa inhibitor, is being evaluated in patients with atrial fibrillation. Angiotensin-converting enzyme inhibitors and angiotensin II receptor-blocking drugs hold promise in atrial fibrillation through cardiac remodelling. Preliminary studies suggest that statins could interfere with the risk of recurrence after electrical cardioversion. Finally, percutaneous methods for the exclusion of left atrial appendage are under investigation in high-risk patients.
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Affiliation(s)
- Stéphane Ederhy
- Assistance Publique Hôpitaux de Paris et Université Pierre et Marie Curie, Service de Cardiologie, Hôpital Saint-Antoine, 184 rue du Faubourg Saint Antoine, 75012, Paris, France
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