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Almakadma A, Simard TJ, Sarma D, Hassett L, Alkhouli M, Packer DL, Holmes DR. Pulmonary vein stenosis – ballooning vs. stenting: a systematic review and meta-analysis. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.2075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Pulmonary vein stenosis (PVS), which is often unrecognized, may arise from a variety of conditions resulting in major morbidity and mortality. In some patients, pharmacological therapy may help but more often in advance stages, mechanical treatment must be considered. Transcatheter approaches, both balloon angioplasty (BA) and stent implantation have been applied. While both may be effective, they continue to be limited by restenosis. Herein, we compare the outcomes following BA and stenting for PVS.
Purpose
PVS presents a challenge for both diagnosis and therapy, with BA and stenting being primarily limited by restenosis. Stenting is performed in most cases and is associated with improved patency rates. Historical comparisons of BA and stenting for PVS have yielded similar results. Our analysis incorporates more conventional studies (2010–2021) and provides a larger stent (N=361) versus BA (N=229) contemporary analysis of the current state of PV intervention practice.
Methods
From January 1, 2010 to August 2, 2021, studies, limited to English language and humans, were assessed in Ovid MEDLINE®, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus. Two independent reviewers screened articles including those in which balloon angioplasty or stenting was performed for pulmonary vein stenosis with reporting of restenosis outcomes and data was independently extracted. Systematic review was performed, and overall restenosis rates were reported across all included studies. Meta-analysis was then performed using RevMan 5.4 assessing rates of restenosis and restenosis requiring repeat intervention.
Results
Our systematic review yielded 34 studies reporting on BA and/or stenting for PVS. Of these, 7 studies (1–7), treating a total of 343 patients with 590 PV interventions (229 BA and 361 Stents) reported restenosis rates with mean follow-up ranging from 10 to 60 months. Stenting was associated with a lower risk of restenosis compared to balloon angioplasty [risk ratio 0.35, 95% CI (0.18, 0.64), p=0.0008] (Figure 1). Restenosis requiring repeat intervention was reported in 5 studies, including 303 patients with 502 PV interventions (160 BA and 342 Stents) with stenting similarly associated with a lower risk of restenosis requiring re-intervention [risk ratio 0.34, 95% CI (0.16, 0.72), p=0.005].
Conclusion
Stenting for pulmonary vein stenosis is associated with reduced risk of restenosis and re-intervention as compared to balloon angioplasty.
Funding Acknowledgement
Type of funding sources: None.
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Affiliation(s)
- A Almakadma
- Mayo Clinic, Cardiovascular Diseases , Rochester , United States of America
| | - T J Simard
- Mayo Clinic, Cardiovascular Diseases , Rochester , United States of America
| | - D Sarma
- Mayo Clinic, Cardiovascular Diseases , Rochester , United States of America
| | - L Hassett
- Mayo Clinic, Mayo Clinic Libraries , Rochester , United States of America
| | - M Alkhouli
- Mayo Clinic, Cardiovascular Diseases , Rochester , United States of America
| | - D L Packer
- Mayo Clinic, Cardiovascular Diseases , Rochester , United States of America
| | - D R Holmes
- Mayo Clinic, Cardiovascular Diseases , Rochester , United States of America
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Poole J, Russo AM, Cha YM, Monahan KH, Al-Khalidi HR, Silverstein AP, Bahnson TD, Mark DB, Lee KL, Packer DL. P2832Outcomes of catheter ablation for atrial fibrillation based on sex: data from the cabana trial. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.1142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Sex-specific outcomes may differ amongst patients receiving catheter ablation for atrial fibrillation (AF).
Purpose
Assess sex-specific outcomes in the patients randomized to catheter ablation or drug therapy in CABANA.
Methods
CABANA randomized 2204 pts with AF to catheter ablation or drug therapy (rate/rhythm-control). The outcomes of combined death, disabling stroke, severe bleeding, or cardiac arrest (intention to treat-ITT) or all-cause death were not different. But, ablation significantly improved combined death or CV hospitalization. This analysis compares clinical characteristics by sex and determines sex-specific hazard ratios based on a comparison of ablation vs drug therapy.
Results
Females were 37.3% of ablation and 37.0% of drug therapy patients. Females were older, more often white race, had less CAD, or sleep apnea, but had higher NYHA Class, higher CHA2DS2VASc, and more often had paroxysmal (v. persistent) AF, and prior AF hospitalization. (Table) HTN, CVA and diabetes were the same (Table).
For the CABANA primary endpoint, an ITT comparison of ablation vs. drug therapy, showed a female hazard ratio (HR) of 1.14 (95% confidence interval (CI) 0.70–1.86), and a male HR of 0.74, (95% CI 0.52–1.06). For all-cause mortality, the female HR was 0.75 (95% CI 0.41–1.40) and male HR was 0.91 (95% CI 0.59–1.40) and for all-cause mortality or CV hospitalization, the female HR was 0.90 (95% CI 0.75–1.09) and male HR was 0.79 (95% CI 0.69–0.92). All interaction p values were non-significant.
Recurrent AF (post 90-day blanking) was significantly reduced for both females and males: female HR 0.64 (95% CI 0.51–0.82), male HR 0.46 95% CI 0.39–0.56), p=0.035
Clinical Characteristics and Outcomes Baseline Characteristics Female (N=818) Male (N=1385) p-value Age: Median (Q1, Q3) 69 (65, 74) 66 (60, 71) <0.001 White 766 (93.9%) 1259 (91.0%) 0.015 CAD 92 (11.2%) 332 (24.0%) <0.001 NYHA ≥II 345 (42.4%) 433 (31.5%) <0.001 Sleep apnea 136 (16.6%) 372 (26.9%) <0.001 CHA2DS2-VASc: Median (Q1, Q3) 3 (3, 4) 2 (1, 3) <0.001 Paroxysmal AF 406 (49.6%) 540 (39.0%) <0.001 Persistent AF 412 (50.4%) 845 (61.0%) AF Hospitalization 353 (43.2%) 521 (37.7%) 0.011
Conclusion
Significant sex-specific outcomes differences were not observed. Sex should not be used as a determining factor in selecting patients for AF therapy.
Acknowledgement/Funding
NIH, St Jude Medical Foundation and Corporation, Biosense Webster Inc., Medtronic Corporation, and Boston Scientific Corporation
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Affiliation(s)
- J Poole
- University of Washington, Seattle, United States of America
| | - A M Russo
- Cooper University Hospital, Camden, United States of America
| | - Y M Cha
- Mayo Clinic, Rochester, United States of America
| | - K H Monahan
- Mayo Clinic, Rochester, United States of America
| | - H R Al-Khalidi
- Duke Clinical Research Institute, Durham, United States of America
| | - A P Silverstein
- Duke Clinical Research Institute, Durham, United States of America
| | - T D Bahnson
- Duke University Medical Center, Durham, United States of America
| | - D B Mark
- Duke University Medical Center, Durham, United States of America
| | - K L Lee
- Duke Clinical Research Institute, Durham, United States of America
| | - D L Packer
- Mayo Clinic, Rochester, United States of America
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3
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Monahan KH, Bunch TJ, Poole JE, Bahnson TD, Al-Khalidi HR, Silverstein AP, Mark DB, Lee KL, Packer DL. 484Impact of AF type on the outcome of atrial fibrillation ablation: insights from the CABANA trial. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz747.0134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Prior studies suggest that catheter ablation (ABL) for atrial fibrillation (AF) is a treatment option for patients (pts) with paroxysmal AF (PAF). Pts with persistent (Per) or long-standing persistent (LSP) were routinely excluded from most ABL based clinical trials. The effectiveness of ABL compared to drug therapy (MED) in relation to underlying AF type has not been evaluated in a large randomized clinical trial.
Objective
To assess the impact of AF type on clinical outcomes of ABL vs. MED in pts with AF.
Methods
The CABANA trial randomized 2204 pts with AF at 126 sites worldwide to ABL vs. MED with rate or rhythm control drugs. The primary endpoint was a composite of death, disabling stroke, severe bleeding, or cardiac arrest. Key secondary endpoints included mortality and recurrence of AF. Outcomes of ABL vs. MED were compared within subgroups defined by AF type using Intention-to-Treat (ITT) analyses.
Results
Of the 2204 pts, 946 had PAF, 1042 had Per and 215 presented with LSP. There were baseline differences among AF types in age, gender, HTN, LVH, CHF and NYHA Class. For the primary endpoint, there were no significant differences between ABL and MED in pts with PAF (hazard ratio (HR) 0.82; 95% confidence interval (CI) 0.51, 1.31), Per (HR 0.87; 95% CI 0.59, 1.28), or LSP (HR 1.01, 95% CI 0.39, 2.61). Likewise, there were no significant treatment differences in mortality; PAF (HR 0.84; 95% CI 0.46, 1.52), Per (HR 0.90; 95% CI 0.56, 1.46) and LSP (HR 0.67, 95% CI 0.23, 1.94). Post-blanking AF (time to first recurrence) was significantly reduced by ABL compared to MED across all AF types (PAF by 51%), (Per by 47%) and (LSP by 36%).
Clinical Characteristics and Outcomes Clinical Outcomes Comparing ABL vs. MED (HR and 95% CI) Interaction p-value Primary Endpoint 0.82 (0.51, 1.31) 0.87 (0.59, 1.28) 1.01 (0.39, 2.61) 0.925 Mortality 0.84 (0.46, 1.52) 0.90 (0.56, 1.46) 0.67 (0.23, 1.94) 0.881 Recurrent AF 0.49 (0.38, 0.62) 0.53 (0.43, 0.65) 0.64 (0.41, 1.01) 0.564
Conclusion
Pts with LSP have a lower proportion of women, and a higher proportion with manifestations of heart failure despite lower CHA2DS2VASc scores. By ITT analysis, there is no significant effect of ABL compared to MED in the primary endpoint or mortality in any AF group. However, ABL is more effective than MED for reducing recurrences of AF regardless of AF type, but with a greater effect in PAF vs Per vs LSP.
Acknowledgement/Funding
NIH, St Jude Medical Foundation and Corporation, Biosense Webster Inc., Medtronic Corporation, and Boston Scientific Corporation
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Affiliation(s)
- K H Monahan
- Mayo Clinic, Rochester, United States of America
| | - T J Bunch
- Intermountain Medical Center, Salt Lake City, United States of America
| | - J E Poole
- University of Washington, Seattle, United States of America
| | - T D Bahnson
- Duke University Medical Center, Durham, United States of America
| | - H R Al-Khalidi
- Duke Clinical Research Institute, Durham, United States of America
| | - A P Silverstein
- Duke Clinical Research Institute, Durham, United States of America
| | - D B Mark
- Duke University Medical Center, Durham, United States of America
| | - K L Lee
- Duke Clinical Research Institute, Durham, United States of America
| | - D L Packer
- Mayo Clinic, Rochester, United States of America
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Hohmann S, Deisher AJ, Suzuki A, Konishi H, Rettmann ME, Lehmann HI, Kruse J, Parker KD, Newman LK, Herman MG, Packer DL. P298Safety of catheter-free VT ablation: Dose-dependent LVEF changes after proton beam therapy of the LV in a porcine model. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy564.p298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- S Hohmann
- Mayo Clinic, Division of Cardiovascular Diseases, Rochester, United States of America
| | - A J Deisher
- Mayo Clinic, Department of Radiation Oncology, Rochester, United States of America
| | - A Suzuki
- Mayo Clinic, Division of Cardiovascular Diseases, Rochester, United States of America
| | - H Konishi
- Mayo Clinic, Division of Cardiovascular Diseases, Rochester, United States of America
| | - M E Rettmann
- Mayo Clinic, Division of Cardiovascular Diseases, Rochester, United States of America
| | - H I Lehmann
- Mayo Clinic, Division of Cardiovascular Diseases, Rochester, United States of America
| | - J Kruse
- Mayo Clinic, Department of Radiation Oncology, Rochester, United States of America
| | - K D Parker
- Mayo Clinic, Division of Cardiovascular Diseases, Rochester, United States of America
| | - L K Newman
- Mayo Clinic, Division of Cardiovascular Diseases, Rochester, United States of America
| | - M G Herman
- Mayo Clinic, Department of Radiation Oncology, Rochester, United States of America
| | - D L Packer
- Mayo Clinic, Division of Cardiovascular Diseases, Rochester, United States of America
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5
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Eichhorn A, Constantinescu A, Lehmann HI, Lugenbiel P, Takami M, Richter D, Prall M, Kaderka R, Thomas D, Bert C, Packer DL, Durante M, Graeff C. SU-C-303-06: Treatment Planning Study for Non-Invasive Cardiac Arrhythmia Ablation with Scanned Carbon Ions in An Animal Model. Med Phys 2015. [DOI: 10.1118/1.4923823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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6
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Rettmann ME, Holmes DR, Johnson SB, Lehmann HI, Robb RA, Packer DL. Analysis of Left Atrial Respiratory and Cardiac Motion for Cardiac Ablation Therapy. Proc SPIE Int Soc Opt Eng 2015; 9415. [PMID: 26405370 DOI: 10.1117/12.2081209] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Cardiac ablation therapy is often guided by models built from preoperative computed tomography (CT) or magnetic resonance imaging (MRI) scans. One of the challenges in guiding a procedure from a preoperative model is properly synching the preoperative models with cardiac and respiratory motion through computational motion models. In this paper, we describe a methodology for evaluating cardiac and respiratory motion in the left atrium and pulmonary veins of a beating canine heart. Cardiac catheters were used to place metal clips within and near the pulmonary veins and left atrial appendage under fluoroscopic and ultrasound guidance and a contrast-enhanced, 64-slice multidetector CT scan was collected with the clips in place. Each clip was segmented from the CT scan at each of the five phases of the cardiac cycle at both end-inspiration and end-expiration. The centroid of each segmented clip was computed and used to evaluate both cardiac and respiratory motion of the left atrium. A total of three canine studies were completed, with 4 clips analyzed in the first study, 5 clips in the second study, and 2 clips in the third study. Mean respiratory displacement was 0.2±1.8 mm in the medial/lateral direction, 4.7±4.4 mm in the anterior/posterior direction (moving anterior on inspiration), and 9.0±5.0 mm superior/inferior (moving inferior with inspiration). At end inspiration, the mean left atrial cardiac motion at the clip locations was 1.5±1.3 mm in the medial/lateral direction, and 2.1±2.0 mm in the anterior/posterior and 1.3±1.2 mm superior/inferior directions. At end expiration, the mean left atrial cardiac motion at the clip locations was 2.0±1.5 mm in the medial/lateral direction, 3.0±1.8 mm in the anterior/posterior direction, and 1.5±1.5 mm in the superior/inferior directions.
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Affiliation(s)
- M E Rettmann
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, 55905, USA
| | - D R Holmes
- Biomedical Imaging Resource, Mayo Clinic, Rochester, Minnesota, 55905, USA
| | - S B Johnson
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, 55905, USA
| | - H I Lehmann
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, 55905, USA
| | - R A Robb
- Biomedical Imaging Resource, Mayo Clinic, Rochester, Minnesota, 55905, USA
| | - D L Packer
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, 55905, USA
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7
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Rettmann ME, Holmes DR, Linte CA, Packer DL, Robb RA. Toward Standardized Mapping for Left Atrial Analysis and Cardiac Ablation Guidance. Proc SPIE Int Soc Opt Eng 2014; 9036:90361K. [PMID: 26401067 PMCID: PMC4576350 DOI: 10.1117/12.2043191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In catheter-based cardiac ablation, the pulmonary vein ostia are important landmarks for guiding the ablation procedure, and for this reason, have been the focus of many studies quantifying their size, structure, and variability. Analysis of pulmonary vein structure, however, has been limited by the lack of a standardized reference space for population based studies. Standardized maps are important tools for characterizing anatomic variability across subjects with the goal of separating normal inter-subject variability from abnormal variability associated with disease. In this work, we describe a novel technique for computing flat maps of left atrial anatomy in a standardized space. A flat map of left atrial anatomy is created by casting a single ray through the volume and systematically rotating the camera viewpoint to obtain the entire field of view. The technique is validated by assessing preservation of relative surface areas and distances between the original 3D geometry and the flat map geometry. The proposed methodology is demonstrated on 10 subjects which are subsequently combined to form a probabilistic map of anatomic location for each of the pulmonary vein ostia and the boundary of the left atrial appendage. The probabilistic map demonstrates that the location of the inferior ostia have higher variability than the superior ostia and the variability of the left atrial appendage is similar to the superior pulmonary veins. This technique could also have potential application in mapping electrophysiology data, radio-frequency ablation burns, or treatment planning in cardiac ablation therapy.
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Affiliation(s)
- M E Rettmann
- Biomedical Imaging Resource, Rochester, Minnesota 55905, USA
| | - D R Holmes
- Biomedical Imaging Resource, Rochester, Minnesota 55905, USA
| | - C A Linte
- Biomedical Engineering and Center for Imaging Science, Rochester Institute of Technology, Rochester, NY 14623, USA
| | - D L Packer
- Division of Cardiovascular Diseases Mayo Clinic, Rochester, Minnesota 55905, USA
| | - R A Robb
- Biomedical Imaging Resource, Rochester, Minnesota 55905, USA
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8
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Killu A, Wan S, Munger TM, Hodge DO, Mulpuru S, Packer DL, Asirvatham SJ, Friedman PA. Procedural and clinical outcomes of combined endocardial-epicardial ablation as compared to endocardial ablation alone. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht310.p4923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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9
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Killu AM, Munger TM, Hodge DO, Mulpuru S, Packer DL, Asirvatham SJ, Friedman PA. Frequency and predictors of post-operative pericardial effusion requiring drainage following percutaneous epicardial access in the electrophysiology laboratory. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht308.p2355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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10
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Witt C, Kushwaha SS, Kane GC, Cha YM, Asirvatham SJ, Oh JK, Packer DL, Powell BD. Changes in pulmonary arterial pressure after atrial fibrillation ablation: incidence, causes, and implications on the stiff left atrial syndrome. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht307.p509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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11
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Yang B, Chen M, Zhang F, Ju W, Chen H, Zhao W, Zhai L, Wang J, Yu J, Shan Q, Zou J, Chen C, Dongjie X, Hou X, Cao K, Dong YX, Yang YZ, Oh JK, Mitsuru M, Powell BD, Larson MD, Buescher TL, Hodge DO, Packer DL, Cha YM, Liu J, Fang P, Hou Y, Li X, Hou C, Ma J, Pu J, Zhang S, Ju W, Yang B, Chen H, Zhang F, Zhai L, Cao K, Chen M, Yu S, Zhao Q, Qin M, Cui H, Huang H, Huang C. AF Ablation III. Europace 2011. [DOI: 10.1093/europace/euq472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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12
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Dong YX, Yang YZ, OhMasakiMitsuru JK, Powell BD, Larson MD, Buescher TL, Hodge DO, Packer DL, Cha YM. e0625 Left Atrial Pressure is a determinant of Recurrence in Atrial Fibrillation after Catheter Ablation. Heart 2010. [DOI: 10.1136/hrt.2010.208967.625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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13
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Powell BD, Packer DL. Does image integration improve atrial fibrillation ablation outcomes, or are other aspects of the ablation the key to success? Europace 2009; 11:973-4. [DOI: 10.1093/europace/eup192] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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14
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Calkins H, Brugada J, Packer DL, Cappato R, Chen SA, Crijns HJ, Damiano RJ, Davies DW, Haines DE, Haissaguerre M, Iesaka Y, Jackman W, Jais P, Kottkamp H, Kuck KH, Lindsay BD, Marchlinski FE, McCarthy PM, Mont JL, Morady F, Nademanee K, Natale A, Pappone C, Prystowsky E, Raviele A, Ruskin JN, Shemin RJ. HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: Recommendations for Personnel, Policy, Procedures and Follow-Up: A report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation. Europace 2008. [DOI: 10.1093/europace/eun341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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15
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Packer DL, Johnson SB, Kolasa MW, Bunch TJ, Henz BD, Okumura Y. New generation of electro-anatomic mapping: full intracardiac ultrasound image integration. Europace 2008; 10 Suppl 3:iii35-41. [DOI: 10.1093/europace/eun231] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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16
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Rettmann ME, Holmes DR, Su Y, Cameron BM, Camp JJ, Packer DL, Robb RA. An integrated system for real-time image guided cardiac catheter ablation. Stud Health Technol Inform 2006; 119:455-60. [PMID: 16404098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Minimally invasive cardiac catheter ablation procedures require effective visualization of the relevant heart anatomy and electrophysiology (EP). In a typical ablation procedure, the visualization tools available to the cardiologist include bi-plane fluoroscopy, real-time ultrasound, and a coarse 3D model which gives a rough representation of cardiac anatomy and electrical activity. Recently, there has been increased interest in incorporating detailed, patient specific anatomical data into the cardiac ablation procedure. We are currently developing a prototype system which both integrates a patient specific, preoperative data model into the procedure as well as fuses the various visualization modalities (i.e. fluoroscopy, ultrasound, EP) into a single display. In this paper, we focus on two aspects of the prototype system. First, we describe the framework for integrating the various system components, including an efficient communication protocol. Second, using a simple two-chamber phantom of the heart, we demonstrate the ability to integrate preoperative data into the ablation procedure. This involves the registration and visualization of tracked catheter points within the cardiac chambers of the preoperative model.
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Affiliation(s)
- M E Rettmann
- Mayo Clinic College of Medicine, Rochester, MN, USA
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17
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Packer DL. Intermittent atrial fibrillation and stroke. Rev Cardiovasc Med 2003; 1:18-9. [PMID: 12506933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Affiliation(s)
- D L Packer
- Mayo Foundation, Rochester, Minnesota, USA
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18
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Packer DL. Congenital long QT syndrome. Rev Cardiovasc Med 2003; 2:26-8. [PMID: 12506941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Affiliation(s)
- D L Packer
- Mayo Foundation, Rochester, Minnesota, USA
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19
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Abstract
Despite the presence of well-described cardiac repolarization abnormalities in heart failure, d,l-sotalol effects on cardiac repolarization have not been evaluated in animal models of CHF. The authors hypothesized that the d,l-sotalol effects on cardiac repolarization are altered in canine dilated cardiomyopathy when compared to controls. Effects of d,l-sotalol were compared in seven dogs with tachycardia induced cardiomyopathy (CHF) and six control animals. In an open-chest model, contact monophasic action potential recordings were obtained from RV and LV endocardium/epicardium during and after two doses of d,l-sotalol (1 mg/kg and 3 mg/kg, each over 20 minutes). Effects of d,l-sotalol on action potential duration at 90% repolarization (APD90) were examined at pacing cycle lengths of 300-1,000 ms. Plasma d,l-sotalol levels were measured at baseline, 10, and 40 minutes following each dose. Prolongation of APD90 by d,l-sotalol, was significantly exaggerated in CHF animals versus controls (P < 0.05, ANOVA). These differences were magnified at slow heart rates (P < 0.05, ANOVA). There were no significant differences in plasma d,l-sotalol levels between the two groups. Effects of d,l-sotalol on cardiac repolarization are exaggerated in CHF without significant alterations in plasma drug levels. While using d,l-sotalol in heart failure, independent additional effects due to ventricular electrical remodeling may be a consideration.
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Affiliation(s)
- S S Chugh
- Department of Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minnesota, USA.
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Wyse DG, Talajic M, Hafley GE, Buxton AE, Mitchell LB, Kus TK, Packer DL, Kou WH, Lemery R, Santucci P, Grimes D, Hickey K, Stevens C, Singh SN. Antiarrhythmic drug therapy in the Multicenter UnSustained Tachycardia Trial (MUSTT): drug testing and as-treated analysis. J Am Coll Cardiol 2001; 38:344-51. [PMID: 11499722 DOI: 10.1016/s0735-1097(01)01402-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES Using data from the Multicenter UnSustained Tachycardia Trial (MUSTT), we examined the factors used to select antiarrhythmic drug therapy and their impact on outcomes. BACKGROUND The MUSTT examined the use of programmed ventricular stimulation (PVS) to guide antiarrhythmic therapy in patients with coronary arteriosclerosis, left ventricular dysfunction and asymptomatic, unsustained ventricular tachycardia (VT). Trial outcomes may reflect factors used to select antiarrhythmic drug therapy. METHODS We compared subgroups of patients with inducible sustained VT randomized to PVS-guided antiarrhythmic therapy (n = 351), in particular those receiving PVS-guided antiarrhythmic drug therapy (n = 142) versus no antiarrhythmic therapy (controls, n = 353). RESULTS "Effective" antiarrhythmic drug therapy (i.e., the term "effective" was used to denote therapy that resulted in noninducible VT or hemodynamically stable induced VT) was found for 142 of the 351 patients (43%), most often at the first or second PVS session (125/142, 88%). Mortality among the 142 patients did not differ from that among control patients. Of these 142 patients, the PVS end point was noninducibility in 91 patients and stable VT in 51 patients. Mortality did not differ between these two groups either, but arrhythmia was numerically more frequent in the PVS-induced stable VT group. Mortality was greatest in the few patients receiving propafenone (unadjusted p = 0.07, adjusted p = 0.14 vs. controls), but mortality with all agents did not differ from that of controls, even after adjustment. CONCLUSIONS Even when presenting the results as favorably as possible, we found no benefit with PVS-guided drug therapy in patients with clinical unsustained VT who had inducible sustained VT. These findings are unaltered by using different end points for PVS or considering the response to individual drugs.
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Affiliation(s)
- D G Wyse
- Division of Cardiology, University of Calgary, Health Science Center, Alberta, Canada.
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Luria DM, Nemec J, Etheridge SP, Compton SJ, Klein RC, Chugh SS, Munger TM, Shen WK, Packer DL, Jahangir A, Rea RF, Hammill SC, Friedman PA. Intra-atrial conduction block along the mitral valve annulus during accessory pathway ablation: evidence for a left atrial "isthmus". J Cardiovasc Electrophysiol 2001; 12:744-9. [PMID: 11469420 DOI: 10.1046/j.1540-8167.2001.00744.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
INTRODUCTION We observed a change in the atrial activation sequence during radiofrequency (RF) energy application in patients undergoing left accessory pathway (AP) ablation. This occurred without damage to the AP and in the absence of a second AP or alternative arrhythmia mechanism. We hypothesized that block in a left atrial "isthmus" of tissue between the mitral annulus and a left inferior pulmonary vein was responsible for these findings. METHODS AND RESULTS Electrophysiologic studies of 159 patients who underwent RF ablation of a left free-wall AP from 1995 to 1999 were reviewed. All studies with intra-atrial conduction block resulting from RF energy delivery were identified. Fluoroscopic catheter positions were reviewed. Intra-atrial conduction block was observed following RF delivery in 11 cases (6.9%). This was evidenced by a sudden change in retrograde left atrial activation sequence despite persistent and unaffected pathway conduction. In six patients, reversal of eccentric atrial excitation during orthodromic reciprocating tachycardia falsely suggested the presence of a second (septal) AP. A multipolar coronary sinus catheter in two patients directly demonstrated conduction block along the mitral annulus during tachycardia. CONCLUSION An isthmus of conductive tissue is present in the low lateral left atrium of some individuals. Awareness of this structure may avoid misinterpretation of the electrogram during left AP ablation and may be useful in future therapies of atypical atrial flutter and fibrillation.
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Affiliation(s)
- D M Luria
- Department of Pediatric Cardiology, University of Utah, University Hospital, Salt Lake City, USA
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Ozcan C, Jahangir A, Friedman PA, Patel PJ, Munger TM, Rea RF, Lloyd MA, Packer DL, Hodge DO, Gersh BJ, Hammill SC, Shen WK. Long-term survival after ablation of the atrioventricular node and implantation of a permanent pacemaker in patients with atrial fibrillation. N Engl J Med 2001; 344:1043-51. [PMID: 11287974 DOI: 10.1056/nejm200104053441403] [Citation(s) in RCA: 223] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND In patients with atrial fibrillation that is refractory to drug therapy, radio-frequency ablation of the atrioventricular node and implantation of a permanent pacemaker are an alternative therapeutic approach. The effect of this procedure on long-term survival is unknown. METHOD We studied all patients who underwent ablation of the atrioventricular node and implantation of a permanent pacemaker at the Mayo Clinic between 1990 and 1998. Observed survival was compared with the survival rates in two control populations: age- and sex-matched members of the Minnesota population between 1970 and 1990 and consecutive patients with atrial fibrillation who received drug therapy in 1993. RESULTS A total of 350 patients (mean [+/-SD] age, 68+/-11 years) were studied. During a mean of 36+/-26 months of follow-up, 78 patients died. The observed survival rate was significantly lower than the expected survival rate based on the general Minnesota population (P<0.001). Previous myocardial infarction (P<0.001), a history of congestive heart failure (P=0.02), and treatment with cardiac drugs after ablation (P=0.03) were independent predictors of death. Observed survival among patients without these three risk factors was similar to expected survival (P=0.43). None of the 26 patients with lone atrial fibrillation died during follow-up (37+/-27 months). The observed survival rate among patients who underwent ablation was similar to that among 229 controls with atrial fibrillation (mean age, 67+/-12 years) who received drug therapy (P=0.44). CONCLUSIONS In the absence of underlying heart disease, survival among patients with atrial fibrillation after ablation of the atrioventricular node is similar to expected survival in the general population. Long-term survival is similar for patients with atrial fibrillation, whether they receive ablation or drug therapy. Control of the ventricular rate by ablation of the atrioventricular node and permanent pacing does not adversely affect long-term survival.
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Affiliation(s)
- C Ozcan
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, Minn 55905, USA
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Shen WK, Low PA, Jahangir A, Munger TM, Friedman PA, Osborn MJ, Stanton MS, Packer DL, Rea RF, Hammill SC. Is sinus node modification appropriate for inappropriate sinus tachycardia with features of postural orthostatic tachycardia syndrome? Pacing Clin Electrophysiol 2001; 24:217-30. [PMID: 11270703 DOI: 10.1046/j.1460-9592.2001.00217.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Inappropriate sinus tachycardia and postural orthostatic tachycardia are ill-defined syndromes with overlapping features. Although sinus node modification has been reported to effectively slow the sinus rate, long-term clinical response has not been adequately assessed. Furthermore, whether patients with postural orthostatic tachycardia would benefit from sinus node modification is unknown. The study prospectively assessed the short- and long-term clinical outcomes of seven consecutive female patients with postural orthostatic tachycardia syndrome and inappropriate sinus tachycardia who were treated with sinus node modification. The study was conducted in a tertiary care center. The electrophysiological and clinical responses were prospectively assessed as defined by autonomic function testing, including Valsalva maneuver, deep breathing, tilt table testing, and quantitative sudomotor axonal reflex testing. Among the study population (mean age was 41+/-6 years), 5 (71%) patients had successful sinus node modification. At baseline, heart rates were 101+/-12 beats/min before modification and 77+/-9 beats/min after modification (P = 0.001). With isoproterenol, heart rates were 136+/-9 and 105+/-12 beats/min (P = 0.002) before and after modification, respectively. The mean heart rate during 24-hour Holter monitoring was also significantly reduced: 96+/-9 and 72+/-6 beats/min (P = 0.005) before and after modification, respectively. Despite the significant reduction in heart rate, autonomic symptom score index (based on ten categories of clinical symptoms) was unchanged before (15.6+/-4.1) and after (14.6+/-3.6) sinus node modification (P = 0.38). Sinus rate can be effectively slowed by sinus node modification. Clinical symptoms are not significantly improved after sinus node modification in patients with inappropriate sinus tachycardia and postural orthostatic tachycardia. A primary subtle autonomic disregulation is frequently present in this population. Sinus node modification is not recommended in this patient population.
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Affiliation(s)
- W K Shen
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA
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24
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Winters SL, Packer DL, Marchlinski FE, Lazzara R, Cannom DS, Breithardt GE, Wilber DA, Camm AJ, Ruskin JN. Consensus statement on indications, guidelines for use, and recommendations for follow-up of implantable cardioverter defibrillators. North American Society of Electrophysiology and Pacing. Pacing Clin Electrophysiol 2001; 24:262-9. [PMID: 11270713 DOI: 10.1046/j.1460-9592.2001.00262.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- S L Winters
- Morristown Memorial Hospital, Morristown, New Jersey, USA
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Abstract
OBJECTIVE Despite the frequent use of anti-arrhythmic drugs in the general population, the electrophysiologic effects of these agents have not been elucidated in congestive heart failure (CHF). METHODS To examine the impact of left ventricular dysfunction on actions of type III anti-arrhythmic drugs, we evaluated the actions of ibutilide in a canine model of pacing-induced dilated cardiomyopathy. Following ablation of the atrioventricular node, effects on action potential duration at 90% (APD(90)) were compared in vivo, between eight CHF animals and seven controls. Monophasic action potential recordings were obtained from right and left ventricular endocardium/epicardium during and after three doses of ibutilide (0. 01, 0.02 and 0.05 mg/kg), at pacing cycle lengths of 300-1000 ms. RESULTS APD(90) prolongation with ibutilide (0.01 mg/kg) was significantly greater in CHF vs. controls (P=0.0026, ANOVA). However, plasma ibutilide levels at this dose, were not significantly different between the two groups. In CHF, maximal effects were observed at the lowest dose, whereas effects were gradual and dose-dependent in controls. With ibutilide administration (0.01 mg/kg), an increased dispersion of left-right ventricular APD(90) was observed in CHF, but not in controls (P=0.03). A trend was observed, for increased incidence of non-sustained polymorphic ventricular tachycardia in CHF. CONCLUSIONS In the presence of CHF, the actions of ibutilide are altered significantly. These findings may reflect altered tissue effects, as a consequence of myocardial electrical remodeling in CHF.
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Affiliation(s)
- S S Chugh
- Division of Cardiovascular Disease, Department of Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, MN, USA.
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Luria DM, Chugh SS, Munger TM, Friedman PA, Rea RF, Packer DL, Jahangir A, Hammill SC, Shen WK. Electrophysiologic characteristics of diverse accessory pathway locations of antidromic reciprocating tachycardia. Am J Cardiol 2000; 86:1333-8. [PMID: 11113408 DOI: 10.1016/s0002-9149(00)01237-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
This study assessed antidromic reciprocating tachycardia (ART) in patients with paraseptal accessory pathways (APs). Previous clinical experience suggests that paraseptal APs are unable to serve as the anterograde limb during ART. Based on the reentry wavelength concept, we hypothesized that anatomic location of a paraseptal AP may not preclude occurrence of ART. If wavelength criteria were met due to prolonged conduction time retrogradely in the atrioventricular node or anterogradely in the AP, ART may be sustained. All patients who had ART in the electrophysiologic laboratory at our institution (1991 to 1998) were studied. Based on fluoroscopically guided electrophysiologic mapping and radiofrequency ablation, AP location was classified as paraseptal, posterior, or lateral. Conduction time and refractoriness measurements were made for all components of the ART circuit. Of 24 patients with ART, 5 (21%) had ART utilizing a paraseptal AP. Anterograde conduction time through the AP and retrograde atrioventricular nodal conduction time were significantly longer in patients with paraseptal versus lateral pathways. Isoproterenol was required for ART induction in 38% of patients with a posterior AP, 36% with lateral AP location, but not in patients with a paraseptal AP. There were no significant differences in tachycardia cycle length or refractoriness of anterograde and/or retrograde components of the macroreentry circuit between the 3 pathway locations. Thus, ART can occur in patients with a paraseptal AP. Slower anterograde pathway conduction, or retrograde atrioventricular nodal conduction renders the wavelength critical for completion of the antidromic re-entrant circuit.
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Affiliation(s)
- D M Luria
- Division of Cardiovascular and Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA
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Tracy CM, Akhtar M, DiMarco JP, Packer DL, Weitz HH. American College of Cardiology/American Heart Association clinical competence statement on invasive electrophysiology studies, catheter ablation, and cardioversion. A report of the American College of Cardiology/American Heart Association/American College of Physicians--American Society of Internal Medicine Task Force on clinical competence. J Am Coll Cardiol 2000; 36:1725-36. [PMID: 11079684 DOI: 10.1016/s0735-1097(00)01085-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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28
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Tracy CM, Akhtar M, DiMarco JP, Packer DL, Weitz HH, Winters WL, Achord JL, Boone AW, Hirshfeld JW, Lorell BH, Rodgers GP, Tracy CM, Weitz HH. American College of Cardiology/American Heart Association Clinical Competence Statement on invasive electrophysiology studies, catheter ablation, and cardioversion: A report of the American College of Cardiology/American Heart Association/American College of Physicians-American Society of Internal Medicine Task Force on Clinical Competence. Circulation 2000; 102:2309-20. [PMID: 11056109 DOI: 10.1161/01.cir.102.18.2309] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Affiliation(s)
- P A Friedman
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota 55905, USA.
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30
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Abstract
Intracardiac echocardiography, defined as ultra-sonographic navigation and visualization within large blood-filled cavities or vessels of the cardio-vascular system, has recently undergone refinement as a clinical tool through technologic advances in transducer miniaturization. Intra-cardiac ultra-sound catheters image at lower frequencies than current conventional intravascular ultrasound catheters used for intracoronary imaging. The lower imaging frequency enables greater tissue penetration, permitting whole-heart evaluation from a right-sided catheter position. Newer devices are steerable, have variable imaging frequency (5.5 to 10 MHz), and full Doppler capability (pulsed, continuous wave, and tissue Doppler). These advances have made intracardiac high-resolution imaging as well as hemodynamic assessment possible. A historical perspective, current capabilities and limitations, and potential clinical and research applications of this new imaging technique are discussed.
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Affiliation(s)
- C J Bruce
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA
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31
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Yin L, Belohlavek M, Packer DL, Greenleaf JF, Seward JB. Myocardial contraction maps using tissue Doppler acceleration imaging. Chin Med J (Engl) 2000; 113:763-8. [PMID: 11776066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
OBJECTIVE To evaluate the tissue Doppler acceleration imaging (TDAI) data which can be used to determine the intramural site of origin of myocardial contraction in response to electrical stimulation. METHODS Six open-chest pigs with left ventricle (LV) pacing were evaluated with TDAI. An epicardial surface scanning method was used to collect short-axis views of the left ventricle. The electrode was implanted from the epicardium through the anterior free wall to an intramural position. RESULTS During pacing, the intramural onset of myocardial acceleration occurred within 33 ms after electrical stimulation and always surrounded the embedded subendocardial end of the pacing needle. The observed short-axis diameter of the area of initial myocardial acceleration ranged from 2.9 mm to 5.0 mm (4.2 +/- 0.9 mm, n = 6). The onset of myocardial acceleration allowed appreciation of the initial intramural myocardial contraction. The spatial size and acceleration magnitude of the initial myocardial acceleration distribution were irregular. CONCLUSION Two-dimensional myocardial acceleration mapping can show the intramural site of origin of myocardial contraction in response to paced electrical stimulation. The location of myocardial acceleration conformed to the site of initial electrical stimulation. The delay to the earliest regional myocardial contraction, 33 ms after paced electrical stimulation, was related to the frame rate of image acquisition.
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Affiliation(s)
- L Yin
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Mayo Foundation, Rochester, Minnesota, USA.
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Friedman PA, Luria D, Fenton AM, Munger TM, Jahangir A, Shen WK, Rea RF, Stanton MS, Hammill SC, Packer DL. Global right atrial mapping of human atrial flutter: the presence of posteromedial (sinus venosa region) functional block and double potentials : a study in biplane fluoroscopy and intracardiac echocardiography. Circulation 2000; 101:1568-77. [PMID: 10747351 DOI: 10.1161/01.cir.101.13.1568] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Previous studies of atrial flutter have found linear block at the crista terminalis; this was thought to predispose the patient to the arrhythmia. More recent observations, however, have demonstrated crista conduction. We sought to characterize the posterior boundary of atrial flutter. METHODS AND RESULTS Patients with counterclockwise flutter (n=20), clockwise flutter (n=3), or both (n=5) were studied using two 20-pole catheters. Biplane fluoroscopy determined catheter positions. During counterclockwise flutter, craniocaudal activation occurred along the entire lateral and posterior right atrial walls. Septal activation proceeded caudocranially. In all patients, a line of block was seen in the posteromedial (sinus venosa) right atrium; this was manifested by the presence of double potentials where the upward and downward activations collided. Anatomic location was confirmed by intracardiac echocardiography in 9 patients. In patients with clockwise flutter, the line of block and double potentials were seen in the same location during counterclockwise flutter, but the activation sequence around the line of block was reversed. Pacing near the site of double potentials during sinus rhythm excluded a fixed line of block, and premature atrial complexes demonstrated functional block with manifest double potentials. In 2 patients, posterior ectopy organized to subsequently initiate isthmus-dependent atrial flutter. CONCLUSIONS (1) A functional line of block is seen at the posteromedial (sinus venosa region) right atrium during counterclockwise and clockwise atrial flutter. (2) All lateral wall right atrial activation can be uniform during flutter, without linear block or double potentials in the region of the crista terminalis. (3) Activation at the site of posteromedial right atrial functional block can organize to subsequently initiate isthmus-dependent atrial flutter.
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Affiliation(s)
- P A Friedman
- Division of Cardiovascular and Internal Medicine, Mayo Clinic, Rochester, MN 55905, USA.
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Abstract
Mitral isthmus ventricular tachycardia uses a reentrant circuit with a critical isthmus of conduction bounded by the mitral valve proximally and a remote inferior infarction scar distally. Successful catheter ablation requires placement of a lesion to transect the isthmus so as to prevent wavefront propagation. We report a case with previously unsuccessful ablation in which focal isthmus ablation failed to eliminate arrhythmia. Electroanatomic mapping demonstrated a wide tachycardia isthmus, and a linear lesion placed from the edge of the inferior infarct (as demonstrated on the three-dimensional voltage electroanatomic map) to the base of the mitral valve successfully eliminated tachycardia. In some patients with mitral isthmus VT, a wide isthmus requires linear lesion placement to fully transect the isthmus and eliminate tachycardia. Electroanatomic mapping can be used to define isthmus boundaries and thus guide successful ablation.
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Affiliation(s)
- P A Friedman
- Division of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
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Bruce CJ, Packer DL, O'Leary PW, Seward JB. Feasibility study: transesophageal echocardiography with a 10F (3.2-mm), multifrequency (5.5- to 10-MHz) ultrasound catheter in a small rabbit model. J Am Soc Echocardiogr 1999; 12:596-600. [PMID: 10398919 DOI: 10.1016/s0894-7317(99)70008-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Transesophageal echocardiography (TEE) is useful in children with congenital heart defects. However, because of available probe size (>/=7 mm diameter), its use is limited to patients weighing more than 3 kg. The aim of this study was to determine the feasibility of TEE in a small animal model by using a 10F (3.2-mm) intravascular ultrasound tipped catheter with a monoplane (longitudinal) 5.5- to 10-MHz phased vector array transducer. Ten New Zealand White rabbits (400 to 3400 g; mean 1580 g) underwent TEE. With animals under general sedation, the probe was blindly introduced into the esophagus. All intracardiac and extracardiac structures were examined, and the images were stored and independently reviewed. All pertinent intracardiac and extracardiac structures were identified except in the 3 smallest rabbits (400 to 600 g). Doppler hemodynamics and color Doppler were possible in each animal. Frequency agility (5.5 to 10 MHz) facilitated optimization of image resolution and penetration. Certain transgastric, 4-chamber, and short-axis views were limited because of the monoplane array. No overt adverse effects were associated with the procedure. Diagnostic TEE can be performed in a small animal model with a 10F, 5.5- to 10-MHz phased vector array ultrasound catheter. Our study suggests that this system has potential in performing diagnostic TEE safely in small, even premature, neonates.
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Affiliation(s)
- C J Bruce
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA
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35
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Abstract
Comprehensive intracardiac Doppler examination under simultaneous direct ultrasound visualization has not been previously possible. This human feasibility study demonstrates that a new 10Fr, 3.2-mm diameter, 5.5- to 10-MHz frequency agile, phased, vector array, ultrasound-tipped catheter with 4-way tip articulation provides diagnostic, high-quality, intracardiac Doppler signals using pulsed and continuous-wave, color flow, and tissue Doppler.
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Affiliation(s)
- C J Bruce
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA
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Abstract
While some factors influencing size of RF lesions in ventricular tissue have been characterized, the effects of catheter electrode-endocardial surface orientation on lesion generation have not been investigated. Therefore, the effects of parallel versus perpendicular catheter electrode-endocardial surface orientation on dimensions of RF lesion produced with 4-, 6-, 8-, 10-, and 12-mm distal electrode lengths were studied in 20 closed-chested dogs. Orientation was established by biplane fluoroscopy and confirmed by intracardiac echocardiography for the majority of energy deliveries (71%). RF voltage was titrated to maintain constant catheter electrode temperature of 75 degrees C for 60 seconds. In the perpendicular orientation, lesion size did not change significantly with increasing electrode lengths. There was a statistically significant interaction between electrode orientation and maximum lesion length (analysis of variance [ANOVA] P = 0.04], lesion width (ANOVA P = 0.01), lesion area (ANOVA P = 0.02), and estimated lesion volume (ANOVA P < 0.005) over all electrode lengths. With parallel tip-tissue orientation, lesion size was a function of increasing electrode length. For 4-, 6-, 8-, 10-, and 12-mm electrodes, maximum lesion surface areas were 95 +/- 38, 97 +/- 38, 119 +/- 29, 147 +/- 52, and 147 +/- 67 mm2, respectively. For electrode lengths 8, 10, and 12 mm, estimated lesion volumes were significantly greater with parallel orientation (P < 0.05 for all). Thus, ventricular lesion size is dependent on catheter electrode length, but only when the catheter is oriented parallel to the endocardial surface. This information may be helpful in increasing lesion dimensions for RF ablation of ventricular tachycardias.
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Affiliation(s)
- S S Chugh
- Department of Internal Medicine, Mayo Foundation, Rochester, Minnesota, USA
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Tsang TS, Freeman WK, Barnes ME, Reeder GS, Packer DL, Seward JB. Rescue echocardiographically guided pericardiocentesis for cardiac perforation complicating catheter-based procedures. The Mayo Clinic experience. J Am Coll Cardiol 1998; 32:1345-50. [PMID: 9809946 DOI: 10.1016/s0735-1097(98)00390-8] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES The purpose of this study was to determine the safety and efficacy of rescue echocardiographically guided pericardiocentesis as a primary strategy for the management of acute cardiac perforation and tamponade complicating catheter-based procedures. BACKGROUND In this era of interventional catheterization, acute tamponade from cardiac perforation as a complication is encountered more frequently. The safety and efficacy of echocardiographically guided pericardiocentesis in this life-threatening situation and outcomes of patients managed by this technique are unknown. METHODS Of the 960 consecutive echocardiographically guided pericardiocenteses performed at the Mayo Clinic (1979 to 1997), 92 (9.6%) were undertaken in 88 patients with acute tamponade that developed in association with a diagnostic or interventional catheter-based procedure. Most of the patients were hemodynamically unstable at the time of pericardiocentesis, with clinically overt tamponade in 40% and frank hemodynamic collapse (systolic blood pressure <60 mm Hg) in 57%. Clinical end points of interest were the success and complication rates of rescue pericardiocentesis and patient outcomes, including the need for other interventions, clinical and echocardiographic follow-up findings and survival. RESULTS Rescue pericardiocentesis was successful in relieving tamponade in 91 cases (99%) and was the only and definitive therapy in 82% of the cases. Major complications (3%) included pneumothorax (n=1), right ventricular laceration (n=1) and intercostal vessel injury with right ventricular laceration (n=1); all were treated successfully. Minor complications (2%) included a small pneumothorax and an instance of transient nonsustained ventricular tachycardia; all were resolved spontaneously. Further surgical intervention was performed in 16 patients (18%). No deaths resulted from the rescue pericardiocentesis procedure itself. Early death (<30 days) in this series was due to injuries from cardiac catheter-based procedures (n=3), perioperative complications (n=2) and underlying cardiac diseases (n=2). Clinical or echocardiographic follow-up for a minimum of 3 months or until death (if <3 months) for recurrent effusion or development of pericardial constriction was achieved in 87 (99%) of the patients. CONCLUSIONS Echocardiographically guided pericardiocentesis was safe and effective for rescuing patients from tamponade and reversing hemodynamic instability complicating invasive cardiac catheter-based procedures. For most patients, this was the definitive and only therapy necessary.
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Affiliation(s)
- T S Tsang
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA
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Abstract
BACKGROUND This study was undertaken to test the hypothesis that beta-adrenergic stimulation in the setting of membrane depolarization will potentiate flecainide-induced conduction slowing. METHODS AND RESULTS To elucidate the potential mechanism for the flecainide proarrhythmia observed in CAST, the voltage dependence of beta-adrenergic modulation of impulse propagation in eight flecainide-superfused canine Purkinje fibers was examined with a dual-microelectrode technique. At physiological membrane potentials (Vm) ([K+]o=5.4 micromol), 1 micromol flecainide decreased Vmax from 698+/-55 to 610+/-72 V/s (P=.003) and squared conduction velocity (theta2) from 2.11+/-1.1 to 1.72+/-0.9 (m/s)2 (P=.001). With K+ depolarization to Vm=-70 mV, flecainide further reduced Vmax from 306+/-101 to 245+/-65 V/s and theta2 from 1.12+/-0.4 to 0.99+/-0.6 (m/s)2, producing a 2.0-mV hyperpolarizing shift of apparent Na+ channel availability curves derived from theta2. The addition of 1 micromol isoproterenol to flecainide-superfused fibers at physiological Vm increased theta2 by 8% to 1.84+/-0.6 (m/s)2 (P<.01) without altering Vmax. At -70 mV, the addition of isoproterenol magnified the flecainide-induced reduction of Vmax an additional 24% to 185+/-52 V/s (P<.01) and theta2 by 17% to 0.82+/-0.5 (m/s)2 (P=.04), producing an additional 1.8-mV (P=.002) and 1.9-mV (P=.002) hyperpolarizing shift in the apparent Na+ channel inactivation curves generated from Vmax and theta2, respectively. At physiological Vm, the action potential duration (APD95) was reduced from 307+/-35 to 269+/-27 ms (P<.001) by flecainide and subsequently to 217+/-4 ms (P<.001) with isoproterenol addition. With 12 mmol/L K+, APD95 decreased from 198+/-23 to 182+/-17 ms (P=.005) with flecainide and to 164+/-10 ms (P=.004) with isoproterenol. CONCLUSIONS At depolarized Vm, isoproterenol amplified the flecainide-induced reduction of Vmax and theta2, suggesting a further adrenergic-mediated reduction of Na+ current. Consequently, the synergy between catecholamines and flecainide at depolarized Vm and the shortened APD95 could facilitate arrhythmogenesis in the presence of underlying ischemia.
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Affiliation(s)
- K T Cragun
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minn 55902, USA
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Zhu WX, Johnson SB, Brandt R, Burnett J, Packer DL. Impact of volume loading and load reduction on ventricular refractoriness and conduction properties in canine congestive heart failure. J Am Coll Cardiol 1997; 30:825-33. [PMID: 9283547 DOI: 10.1016/s0735-1097(97)00203-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVES This investigations was undertaken to examine the alteration of electrophysiologic properties, including refractoriness, strength-interval relations and conduction, with the development of heart failure and to characterize the impact of volume loading on these indexes in the cardiomyopathic setting. METHODS Electrophysiologic properties in eight dogs with pacing-induced dilated cardiomyopathy were compared with those in six control dogs before and after rapid infusion of 800 ml of intravenous saline. RESULTS The right ventricular (RV) and left ventricular (LV) effective refractory period (ERP) and absolute refractory period (ARP) were significantly longer in dogs with pacing-induced cardiomyopathy than in control dogs: RV ERP 181 +/- 11 ms versus 138 +/- 7 ms (mean +/- SD) (p < 0.0001) and anterior LV ERP 177 +/- 13 ms versus 128 +/- 11 ms (p < 0.0001), respectively; ARP 159 +/- 14 ms versus 114 +/- 7 ms (p < 0.0001) at the RV site and 153 +/- 12 versus 117 +/- 5 ms (p < 0.0001) at the anterior LV site. After volume loading in cardiomyopathic animals, posterior and anterior LV ERPs became prolonged to 178 +/- 5 ms (p = 0.004) and 189 +/- 14 ms (p = 0.065), respectively, shifting the strength-interval relation in the direction of longer S1S2 coupling intervals. Anterior LV monophasic action potential durations at 90% repolarization also became prolonged from 192 +/- 10 ms to 222 +/- 23 ms (p < 0.012) with volume loading. These findings were not altered by subsequent sodium nitroprusside. Local conduction times parallel and perpendicular to fiber orientation were not altered by development of cardiomyopathy or volume alterations. CONCLUSIONS The development of dilated cardiomyopathy results in significant prolongation of refractoriness and repolarization that is increased further by volume augmentation but is not reversed by pharmacologic load reduction. Although these abnormalities may contribute to the environment needed for a non-reentrant, triggered or stretch-mediated arrhythmogenic process in cardiomyopathic states, additional studies will be required to demonstrate such a focal mechanism conclusively.
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Affiliation(s)
- W X Zhu
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA
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Shen WK, Munger TM, Stanton MS, Osborn MJ, Hammill SC, Packer DL. Effects of slow pathway ablation on fast pathway function in patients with atrioventricular nodal reentrant tachycardia. J Cardiovasc Electrophysiol 1997; 8:627-38. [PMID: 9209963 DOI: 10.1111/j.1540-8167.1997.tb01825.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
INTRODUCTION This study investigated whether fast pathway conduction properties are altered by slow pathway ablation in patients with AV nodal reentrant tachycardia. METHODS AND RESULTS Forty consecutive patients who underwent successful ablation of the slow pathway were prospective subjects for the study. Isoproterenol was used to enhance conduction and to differentiate interactive mechanisms. Potential electrotonic interactions were assessed by comparing patients with and those without residual dual AV node physiology after slow pathway ablation. Paired and unpaired t-tests were used when appropriate P < 0.05 was considered statistically significant. In the entire study population, heart rates were not significantly different before and after slow pathway ablation (RR = 770 +/- 114 msec before and 745 +/- 99 msec after, P = 0.07). Anterograde fast pathway conduction properties were unchanged after slow pathway ablation (effective refractory period, 348 +/- 84 msec before and 336 +/- 86 msec after, P = 0.13; shortest 1:1 conduction, 410 +/- 93 msec before and 400 +/- 82 msec after, P = 0.39). Retrograde fast pathway characteristics also were similar before and after ablation. Neither anterograde nor retrograde fast pathway conduction properties during isoproterenol infusion were changed by slow pathway ablation. When the study population was further divided into patients with (n = 13) or without (n = 27) residual dual AV node physiology, no significant change was detected in fast pathway function in either group after slow pathway ablation. CONCLUSIONS Fast pathway conduction characteristics were not affected by slow pathway ablation. In patients with AV nodal reentrant tachycardia, observations suggest that fast and slow pathways are functionally distinct.
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Affiliation(s)
- W K Shen
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA
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Packer DL, Munger TM, Johnson SB, Cragun KT. Mechanism of lethal proarrhythmia observed in the Cardiac Arrhythmia Suppression Trial: role of adrenergic modulation of drug binding. Pacing Clin Electrophysiol 1997; 20:455-67. [PMID: 9058849 DOI: 10.1111/j.1540-8159.1997.tb06204.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A variety of recent in vivo studies have sought to clarify the mechanism underlying the proarrhythmic response of flecainide in the Cardiac Arrhythmia Suppression Trial (CAST). Increased inducibility of relatively stable ventricular arrhythmias in subacute and chronic postinfarction models has been universally observed. The arrhythmogenesis has been explained in part by drug induced modulation of anisotropic conduction in persistently ischemic tissue, increased durations of vulnerable windows, enhanced generation of unidirectional block with the introduction of extrastimuli, variability of repolarization within the ventricular wall, and the creation of stable reentrant circuits with narrow central zones of propagation. While these data explain arrhythmogenesis in general, malignant ventricular arrhythmia capable of producing the excess sudden or arrhythmic death mortality in the CAST trial have not been universally observed, nor have the proported beneficial effects of beta-blockade seen in the CAST trial and other studies been explained. Additional studies examining the adrenergic modulation of flecainide binding have shown reversal of flecainide effects in normal tissue, but paradoxical amplification of flecainide induced conduction slowing in depolarized tissue. This variable effect in normal versus abnormal tissue produces significant dispersions of conduction with an expected increased propensity for conduction failure in response to ectopy, increased liminal length for impulse propagation, enhanced vulnerability to premature extrastimuli, and completed reentrant circuits in regions of depressed membrane potentials. This, along with the decrease in action potential duration and accompanying refractoriness in the setting of adrenergic modulation may favor more malignant double wavelet or unstable ventricular arrhythmias.
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Affiliation(s)
- D L Packer
- Division of Cardiac Electrophysiology/Cardiology, Mayo Foundation, Rochester, Minnesota, USA.
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Bardy GH, Marchlinski FE, Sharma AD, Worley SJ, Luceri RM, Yee R, Halperin BD, Fellows CL, Ahern TS, Chilson DA, Packer DL, Wilber DJ, Mattioni TA, Reddy R, Kronmal RA, Lazzara R. Multicenter comparison of truncated biphasic shocks and standard damped sine wave monophasic shocks for transthoracic ventricular defibrillation. Transthoracic Investigators. Circulation 1996; 94:2507-14. [PMID: 8921795 DOI: 10.1161/01.cir.94.10.2507] [Citation(s) in RCA: 126] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND The most important factor for improving out-of-hospital ventricular fibrillation survival rates is early defibrillation. This can be achieved if small, lightweight, inexpensive automatic external defibrillators are widely disseminated. Because automatic external defibrillator size and cost are directly affected by defibrillation waveform shape and because of the favorable experience with truncated biphasic waveforms in implantable cardioverter-defibrillators, we compared the efficacy of a truncated biphasic waveform with that of a standard damped sine monophasic waveform for transthoracic defibrillation. METHODS AND RESULTS The principal goal of this multicenter, prospective, randomized, blinded study was to compare the first-shock transthoracic defibrillation efficacy of a 130-J truncated biphasic waveform with that of a standard 200-J monophasic damped sine wave pulse using anterior thoracic pads in the course of implantable cardioverter-defibrillator testing. Pad-pad ECGs were also examined after transthoracic defibrillation. After the elimination of data for 24 patients who did not meet all protocol criteria, the results from 294 patients were analyzed. The 130-J truncated biphasic pulse and the 200-J damped sine wave monophasic pulse resulted in first-shock efficacy rates of 86% and 86%, respectively (P = .97). ST-segment levels measured 10 seconds after the shock in 151 patients in sinus rhythm were -0.26 +/- 1.58 and -1.86 +/- 1.93 mm for the 130- and 200-J shocks, respectively (P < .0001). CONCLUSIONS We found that 130-J biphasic truncated transthoracic shocks defibrillate as well as the 200-J monophasic damped sine wave shocks that are traditionally used in standard transthoracic defibrillators and result in fewer ECG abnormalities after the shock.
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Affiliation(s)
- G H Bardy
- Department of Medicine, University of Washington (Seattle), USA.
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Stevens SK, Haffajee CI, Naccarelli GV, Schwartz KM, Luceri RM, Packer DL, Rubin AM, Kowey PR. Effects of oral propafenone on defibrillation and pacing thresholds in patients receiving implantable cardioverter-defibrillators. Propafenone Defibrillation Threshold Investigators. J Am Coll Cardiol 1996; 28:418-22. [PMID: 8800119 DOI: 10.1016/0735-1097(96)00156-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES The effects of propafenone, a predominantly class IC antiarrhythmic drug, on defibrillation and pacing thresholds were evaluated in patients undergoing cardioverter-defibrillator implantation. BACKGROUND Previous studies have shown that the class IC agents encainide and flecainide may increase the energy requirements for pacing and defibrillation. Animal studies with propafenone have shown inconsistent results regarding its effect on defibrillation energy requirements. This report investigated the effects of propafenone on defibrillation and pacing thresholds in humans. METHODS After cardioverter-defibrillator implantation, 47 patients were enrolled in a double-blind, three-way parallel, randomized trial of 450 mg/day (Group 1) or 675 mg/day (Group 2) of oral propafenone or placebo (Group 3) for 3 to 7 days. Predischarge defibrillation and pacing thresholds after treatment were compared with baseline thresholds obtained at implantation. RESULTS There was no statistically significant difference between implantation and predischarge defibrillation thresholds in the three groups (Group 1: [mean +/- SE] 11.0 +/- 1.3 vs. 12.1 +/- 1.5 J; Group 2: 11.5 +/- 1.1 vs. 13.6 +/- 1.3 J; Group 3: 12.5 +/- 1.2 vs. 13.3 +/- 1.6 J), and no significant difference between treatment groups was found with a 0.86 power to detect a 5-J difference between groups. Paired pulse width pacing thresholds at 2.8 V were compared in 14 patients. A small increase of 0.02 ms was noted at predischarge testing in patients treated with propafenone and placebo. CONCLUSIONS Short-term oral propafenone (450 and 675 mg/day) does not significantly affect defibrillation or pacing thresholds. Concomitant use of propafenone in patients with implantable cardioverter-defibrillators with recurrent ventricular or atrial tachyarrhythmias should not interfere with proper device function.
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Affiliation(s)
- S K Stevens
- St. Elizabeth's Medical Center, Cardiovascular Division, Boston, Massachusetts 02135, USA
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Abstract
OBJECTIVE To present the results of investigation of a new application of invasive ultrasonography-ultrasound cardioscopy, a procedure in which a self-contained ultrasound device is capable not only of producing an under-blood field of view but also of delivering diagnostic and therapeutic tools. DESIGN Twenty adult mongrel dogs were studied with the ultrasound cardioscopy device during experimental catheter ablation procedures. MATERIAL AND METHODS A rigid prototype probe, 34 cm long and 8 mm in diameter with a 7-MHz side-viewing transducer at the tip and an 8-F diameter tool delivery port, was introduced through the right external jugular vein into the right heart chambers. Remote and device-directed ablation procedures were monitored. Subsequently, the canine hearts were excised and examined. RESULTS The self-contained cardioscopy device with a contained ablation catheter could both direct and visualize a specified ablation injury. Under-blood observation of the details of the ablation procedure was possible. Although a learning curve existed for appropriate manipulation of the device, inspection of the excised hearts showed that the size of the injury was accurately predicted with use of ultrasound cardioscopy. CONCLUSION Ultrasound cardioscopy is a promising means of performing precise under-blood diagnostic and therapeutic maneuvers.
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Affiliation(s)
- J B Seward
- Division of Cardiovascular Diseases, Mayo Clinic Rochester, MN 55905, USA
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Abstract
OBJECTIVES This study examined the hypothesis that adenosine could provoke a vasovagal response in susceptible patients. Mechanisms of the vasovagal response were further explored by studying the adenosine-mediated reactions. BACKGROUND Increased sympathetic activity is frequently observed before vasovagal syncope. Recent studies have demonstrated that adenosine, in addition to its direct bradycardiac and vasodilatory effects, can increase sympathetic discharge by activating cardiovascular afferent nerves. METHODS The effects of adenosine and head-up tilt-table testing with or without isoproterenol were prospectively evaluated in 85 patients examined for syncope after negative results of electrophysiologic testing (51 men and 34 women, mean [+/- SD] age 61 +/- 17 years). Adenosine bolus injections of 6 mg and 12 mg were sequentially administered to patients in the upright position. The same protocol was implemented in 14 normal control subjects (7 men and 7 women, mean [+/- SD] age 38 +/- 10 years). RESULTS Transient hypertension or tachycardia was observed in 57 (67%) and 20 (24%) patients after administration of 6 mg and 12 mg of adenosine, respectively, during the immediate phase (first 15 s), suggesting direct sympathetic activation. Hypotension and reflex tachycardia were observed in all patients during the delayed phase (15 to 60 s after adenosine injection), suggesting baroreceptor unloading. A vasovagal response was induced in 22 (26%) and 29 (34%) patients after adenosine administration and during tilt-table testing. Inducibility of a vasovagal response by these two methods was comparable (p = 0.12). Of the control subjects, one (7%) had a vasovagal response after adenosine administration and one (7%) had a positive response during tilt-table testing. CONCLUSIONS These observations support the idea that adenosine is an endogenous modulator of the cardiac excitatory afferent nerves. Sympathetic activation by adenosine can be direct (i.e., cardiac excitatory afferent nerves) and indirect (i.e., vasodilation and reflex sympathetic activation). Adenosine could be an important modulator in triggering a vasovagal response in susceptible patients during examination for syncope.
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Affiliation(s)
- W K Shen
- Division of Cardiovascular Diseases and Internal Medicine, Section of Biostatistics and Peripheral Neuropathy Research Laboratory, Mayo Clinic, Rochester, Minnesota 55905, USA
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Abstract
A 52-year-old female with no structural heart disease presented with a right bundle branch block (RBBB)/right axis deviation tachycardia with a cycle length of 300 msec. P waves were not discernible on the surface ECG. Baseline electrophysiology study in the drug-free state revealed no evidence for anterograde or retrograde conducting accessory pathways (APs) or for dual AV node physiology. Retrograde VA block with AV dissociation was present at a ventricular paced cycle length of 600 msec (sinus cycle length of 635-700 msec). AV nodal Wenckebach occurred during decremental atrial pacing at a cycle length of 300 msec. During isoproterenol administration, a left lateral AP with retrograde only conduction became manifest with 1:1 VA conduction to 380 msec. No anterograde AP conduction was present. Orthodromic reciprocating tachycardia with a cycle length of 285-315 msec was easily induced. We conclude that total functional conduction block can exist in APs, and unmasking of total conduction block can be accomplished with isoproterenol. All patients with undiagnosed tachycardias should have full repeat stimulation studies during adrenergic stimulation if the initial baseline evaluation is nondiagnostic.
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Affiliation(s)
- D W Frazier
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN 55905, USA
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Hammill SC, Packer DL, Stanton MS, Fetter J. Termination and acceleration of ventricular tachycardia with autodecremental pacing, burst pacing, and cardioversion in patients with an implantable cardioverter defibrillator. Multicenter PCD Investigator Group. Pacing Clin Electrophysiol 1995; 18:3-10. [PMID: 7700828 DOI: 10.1111/j.1540-8159.1995.tb02469.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This multicenter study reports the outcome of ventricular tachycardia (VT) therapy (conversion or acceleration) and the relationship to initial tachycardia cycle length and other clinical variables using an implantable device with the capability of autodecremental or burst pacing, cardioversion, and defibrillation. The device was implanted in 444 patients (mean age 58 +/- 15 years) with 1,240 episodes of VT induced with noninvasive programming and reported in a multicenter database. Only the first sequence attempted for conversion by pacing or cardioversion was assessed, and cardioversion energies were 0.2-5 J. Autodecremental pacing was used to treat 700 induced episodes of VT during titration of pacing therapies (57% converted and 12% accelerated), burst pacing to treat 357 episodes (49% converted under 11% accelerated), and cardioversion to treat 183 episodes (82% converted and 4% accelerated). Cardioversion was the most effective treatment and had the lowest acceleration rate. Shorter VT cycle lengths were more likely to accelerate with burst pacing and longer VT cycle lengths to convert with both burst and autodecremental pacing. Patients with higher ejection fractions were more likely to convert with autodecremental and burst pacing. Use of cardioversion, higher ejection fraction, absence of unrepaired aneurysm, longer VT cycle lengths, coronary artery disease, and use of autodecremental pacing predicted conversion. Lower ejection fraction and VT cycle lengths < or = 300 msec predicted tachycardia acceleration.
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Affiliation(s)
- S C Hammill
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, MN 55905
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Abstract
Permanent pacing can prevent recurrent symptoms and reduce mortality in elderly patients with symptomatic high-degree atrioventricular (AV) block. However, long-term survival with respect to comparable control subjects has not been well defined. In our study, relative long-term survival and prognostic predictors after permanent pacemaker implantation for symptomatic high-degree AV block were assessed among all residents of Olmsted County, Minnesota, who were > or = 65 years old. Of the 154 patients, 77 were men and 77 were women (mean age 80 +/- 7 years). Follow-up was 0.1 to 19.8 years (mean 4.2 +/- 2.8). Sixty-nine patients had isolated AV block and 85 had coexisting heart disease. Observed survival at 1, 3, 5, and 10 years was 85%, 68%, 52%, 21%, and 72%, 50%, 31%, 11% for patients with isolated AV block and patients with coexisting heart disease, respectively (p = 0.006). Observed survival in patients 65 to 79 years old with isolated AV block was comparable to age- and sex-matched cohorts (p = 0.53), but in patients aged > or = 80 years, it was less than that for control subjects (p = 0.014). In patients with coexisting heart disease, observed survival was less than that for control subjects in patients 65 to 79 years old (p < 0.001) and > or = 80 years (p < 0.001). Multivariate analysis identified congestive heart failure, chronic obstructive pulmonary disease, age, syncope, insulin-dependent diabetes mellitus, and male gender as independent predictors of increased mortality.
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Affiliation(s)
- W K Shen
- Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905
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Abstract
We studied fibroblast activity during tendon healing with an in vitro tendon culture model. Tendons were embedded in a translucent collagen gel matrix whose porous nature permitted free nutrient diffusion, fibroblast migration out of the tendon, and microphotographic documentation of fibroblast activity. Experiments were performed using one or more tendons cultured in the same collagen gel. We identified three zones of fibroblast activity in the gel. Zone I was an area of randomly dispersed cells directly adjacent to the tendon where collagen synthesis and remodeling were probably taking place. In zone II, spindle-shaped fibroblasts were aligned pointing away from the cut tendon end forming a sunburst-like aggregate of cells. Zone II fibroblasts were responsible for formation of migration trails by exerting a mechanical force on the collagen matrix, which was evident as a local gel contraction. Zone III was the leading edge of the sunburst populated by the fastest moving fibroblasts, which responded to guidance by other cut tendon ends. We speculate that the collagen gel used in the culture system may help maintain a chemotactic concentration gradient that allows fibroblasts to locate other distal cut tendon surfaces also embedded in the collagen gel.
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Affiliation(s)
- D L Packer
- Department of Surgery, Wayne State University, Detroit, MI 48201
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