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Renard E, Surget E, Walton RD, Michel C, Benoist D, Dubes V, Guillot B, Martinez ME, Hocini M, Haïssaguerre M, Bernus O. Distinct Electrogram Features and Ventricular Arrhythmia Induction Modes Between Repolarization and Conduction Heterogeneities. JACC Clin Electrophysiol 2024; 10:1424-1438. [PMID: 38661605 DOI: 10.1016/j.jacep.2024.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 03/01/2024] [Accepted: 03/04/2024] [Indexed: 04/26/2024]
Abstract
BACKGROUND Recent clinical studies have indicated the presence of localized electrical abnormalities in idiopathic ventricular fibrillation and J-wave syndrome patients. OBJECTIVES This study aims to characterize the specific electrical signatures of localized repolarization and conduction heterogeneities and their respective role in vulnerability to arrhythmias. METHODS Optical mapping was performed in porcine right ventricles with local: 1) repolarization shortening; 2) conduction slowing; or 3) structural heterogeneity induced by locally perfusing: 1) pinacidil (20 μmol/L, n = 13); or 2) flecainide (2 μmol/L, n = 13) via an epicardial catheter; or 3) by local epicardial tissue destruction (9 radiofrequency lesions n = 12). Electrograms were recorded (n = 5 in each group) and spontaneous and induced arrhythmias were quantified and optically mapped. RESULTS Electrograms were normal in (1) but showed local fragmentation in 40% of preparations in (2) with greater effects observed at high pacing frequencies dependent on the wavefront direction. In (3), the structural substrate alone increased the width and number of peaks in the electrograms, and addition of flecainide induced pronounced fragmentation (≥3 peaks and ≥70 ms) in all cases. Occurrence of spontaneous arrhythmias was significantly increased in (1) and (2) (P < 0.0001 and 0.05, respectively, vs baseline) and were triggered by ectopies. Vulnerability to arrhythmias at high pacing frequencies (≥2 Hz) was the lowest in (1) and greatest in (2). CONCLUSIONS Microstructural substrates have the most pronounced impact on electrograms, especially when combined with sodium channel blockers, whereas local action potential duration shortening does not lead to electrogram fragmentation even though it is associated with the highest prevalence of spontaneous arrhythmias.
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Affiliation(s)
- Estelle Renard
- IHU LIRYC, L'Institut des maladies du RYthme Cardiaque, Fondation Bordeaux Université, Bordeaux, France; University of Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France.
| | - Elodie Surget
- IHU LIRYC, L'Institut des maladies du RYthme Cardiaque, Fondation Bordeaux Université, Bordeaux, France; University of Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
| | - Richard D Walton
- IHU LIRYC, L'Institut des maladies du RYthme Cardiaque, Fondation Bordeaux Université, Bordeaux, France; University of Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
| | - Cindy Michel
- IHU LIRYC, L'Institut des maladies du RYthme Cardiaque, Fondation Bordeaux Université, Bordeaux, France; University of Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
| | - David Benoist
- IHU LIRYC, L'Institut des maladies du RYthme Cardiaque, Fondation Bordeaux Université, Bordeaux, France; University of Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
| | - Virginie Dubes
- IHU LIRYC, L'Institut des maladies du RYthme Cardiaque, Fondation Bordeaux Université, Bordeaux, France; University of Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
| | - Bastien Guillot
- IHU LIRYC, L'Institut des maladies du RYthme Cardiaque, Fondation Bordeaux Université, Bordeaux, France; University of Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
| | - Marine E Martinez
- IHU LIRYC, L'Institut des maladies du RYthme Cardiaque, Fondation Bordeaux Université, Bordeaux, France; University of Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
| | - Mélèze Hocini
- IHU LIRYC, L'Institut des maladies du RYthme Cardiaque, Fondation Bordeaux Université, Bordeaux, France; University of Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France; CHU de Bordeaux, Département d'électrophysiologie et de stimulation cardiaques, Hôpital Cardiologique du Haut-Lévêque, Pessac, France
| | - Michel Haïssaguerre
- IHU LIRYC, L'Institut des maladies du RYthme Cardiaque, Fondation Bordeaux Université, Bordeaux, France; University of Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France; CHU de Bordeaux, Département d'électrophysiologie et de stimulation cardiaques, Hôpital Cardiologique du Haut-Lévêque, Pessac, France
| | - Olivier Bernus
- IHU LIRYC, L'Institut des maladies du RYthme Cardiaque, Fondation Bordeaux Université, Bordeaux, France; University of Bordeaux, Inserm, Centre de Recherche Cardio-Thoracique de Bordeaux, Bordeaux, France
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Al Najem S, Groll A, Schmermund A, Nowak B, Voigtländer T, Kaltenbach U, Dohmann P, Andresen D, Scharhag J. Correlation of Walking Activity and Cardiac Hospitalizations in Coronary Patients for 1 Year Post Cardiac Rehabilitation: The More Steps, the Better! CLINICAL MEDICINE INSIGHTS-CARDIOLOGY 2022; 16:11795468221116841. [PMID: 36046182 PMCID: PMC9421021 DOI: 10.1177/11795468221116841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 07/04/2022] [Indexed: 11/29/2022]
Abstract
Problem Reducing risk by improving fitness is one of the main objectives of cardiac rehabilitation (CR). To estimate how the number of steps/day post-CR affects coronary patients' prognosis, we analyzed its correlation with the occurrence of death, hospitalizations, and heart complaints, and if and how other variables (ejection fraction (EF), gender, age) relate to those. Methods One hundred eleven patients (male = 91, female = 20; average age ± standard deviation (SD): 61 ± 11 years) who had been in CR due to recent coronary revascularization or chronic coronary syndrome could be enrolled. Patients were advised to document their steps (daily), blood pressure (daily), weight (weekly) and occurrences of a cardiac event in a diary for 1 year post-CR. A Cox proportional hazard model was used to examine the influence of steps/day, EF, gender, and age until the occurrence of an event. Kaplan-Meier curves were generated to compare patients' profiles. Results Average steps/day of patients post-CR were 7333 (SD 4426). Increased walking activity reduced risk for cardiac hospitalization (constant steps/day: 5000 vs 7500, hazard rate (HR) reduction of 0.43; 10 000 vs 12 500, HR reduction of 0.20) and risk was higher in patients with an EF < 55% versus EF ⩾ 55% (HR increase of 2.88). Median follow-up time post-CR was 218 days. No patient died, 25 were hospitalized. Discussion Monitoring the number of steps of coronary patients post CR could be valuable for estimating patients' prognosis.
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Affiliation(s)
- Sinann Al Najem
- German Heart Foundation, Frankfurt, Germany
- Institute of Sports and Preventive Medicine, Saarbrücken, Germany
| | - Andreas Groll
- Departement of Statistics, TU Dortmund University, Dortmund, Germany
| | - Axel Schmermund
- CCB-Herzwerk, Frankfurt, Germany
- Cardioangiologisches Centrum Bethanien (CCB), Frankfurt, Germany
| | - Bernd Nowak
- CCB-Herzwerk, Frankfurt, Germany
- Cardioangiologisches Centrum Bethanien (CCB), Frankfurt, Germany
| | - Thomas Voigtländer
- CCB-Herzwerk, Frankfurt, Germany
- Cardioangiologisches Centrum Bethanien (CCB), Frankfurt, Germany
| | | | | | | | - Jürgen Scharhag
- Institute of Sports and Preventive Medicine, Saarbrücken, Germany
- Department of Sports Medicine, Exercise Physiology and Prevention, Institute of Sport Science, University of Vienna, Vienna, Austria
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Müller P, Leow MKS, Dietrich JW. Minor perturbations of thyroid homeostasis and major cardiovascular endpoints—Physiological mechanisms and clinical evidence. Front Cardiovasc Med 2022; 9:942971. [PMID: 36046184 PMCID: PMC9420854 DOI: 10.3389/fcvm.2022.942971] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 07/22/2022] [Indexed: 11/13/2022] Open
Abstract
It is well established that thyroid dysfunction is linked to an increased risk of cardiovascular morbidity and mortality. The pleiotropic action of thyroid hormones strongly impacts the cardiovascular system and affects both the generation of the normal heart rhythm and arrhythmia. A meta-analysis of published evidence suggests a positive association of FT4 concentration with major adverse cardiovascular end points (MACE), but this association only partially extends to TSH. The risk for cardiovascular death is increased in both subclinical hypothyroidism and subclinical thyrotoxicosis. Several published studies found associations of TSH and FT4 concentrations, respectively, with major cardiovascular endpoints. Both reduced and elevated TSH concentrations predict the cardiovascular risk, and this association extends to TSH gradients within the reference range. Likewise, increased FT4 concentrations, but high-normal FT4 within its reference range as well, herald a poor outcome. These observations translate to a monotonic and sensitive effect of FT4 and a U-shaped relationship between TSH and cardiovascular risk. Up to now, the pathophysiological mechanism of this complex pattern of association is poorly understood. Integrating the available evidence suggests a dual etiology of elevated FT4 concentration, comprising both ensuing primary hypothyroidism and a raised set point of thyroid function, e. g. in the context of psychiatric disease, chronic stress and type 2 allostatic load. Addressing the association between thyroid homeostasis and cardiovascular diseases from a systems perspective could pave the way to new directions of research and a more personalized approach to the treatment of patients with cardiovascular risk.
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Affiliation(s)
- Patrick Müller
- Department for Electrophysiology, Medical Hospital I, Klinikum Vest, Recklinghausen, NRW, Germany
| | - Melvin Khee-Shing Leow
- Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
- Department of Endocrinology, Tan Tock Seng Hospital, Singapore, Singapore
- Metabolic Disorders Research Programme, Lee Kong Chian School of Medicine, Singapore, Singapore
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Johannes W. Dietrich
- Diabetes, Endocrinology and Metabolism Section, Department of Internal Medicine I, St. Josef Hospital, Ruhr University Bochum, Bochum, NRW, Germany
- Diabetes Centre Bochum/Hattingen, St. Elisabeth-Hospital Blankenstein, Hattingen, NRW, Germany
- Centre for Rare Endocrine Diseases, Ruhr Centre for Rare Diseases (CeSER), Ruhr University Bochum and Witten/Herdecke University, Bochum, NRW, Germany
- Centre for Diabetes Technology, Catholic Hospitals Bochum, Ruhr University Bochum, Bochum, NRW, Germany
- *Correspondence: Johannes W. Dietrich
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Sympathetic activation and ventricular arrhythmias: New insights from surface electrogram recordings. Heart Rhythm 2015; 12:621-622. [DOI: 10.1016/j.hrthm.2014.12.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Indexed: 11/17/2022]
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Vadakkumpadan F, Trayanova N, Wu KC. Image-based left ventricular shape analysis for sudden cardiac death risk stratification. Heart Rhythm 2014; 11:1693-700. [PMID: 24854217 DOI: 10.1016/j.hrthm.2014.05.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Indexed: 11/25/2022]
Abstract
BACKGROUND Low left ventricular ejection fraction (LVEF), the main criterion used in the current clinical practice to stratify sudden cardiac death (SCD) risk, has low sensitivity and specificity. OBJECTIVE To uncover indices of left ventricular (LV) shape that differ between patients with a high risk of SCD and those with a low risk. METHODS By using clinical cardiac magnetic resonance imaging and computational anatomy tools, a novel computational framework to compare 3-dimensional LV endocardial surface curvedness, wall thickness, and relative wall thickness between patient groups was implemented. The framework was applied to cardiac magnetic resonance data of 61 patients with ischemic cardiomyopathy who were selected for prophylactic implantable cardioverter-defibrillator treatment on the basis of reduced LVEF. The patients were classified by outcome: group 0 had no events; group 1, arrhythmic events; and group 2, heart failure events. Segmental differences in LV shape were assessed. RESULTS Global LV volumes and mass were similar among groups. Compared with patients with no events, patients in groups 1 and 2 had lower mean shape metrics in all coronary artery regions, with statistical significance in 9 comparisons, reflecting wall thinning and stretching/flattening. CONCLUSION In patients with ischemic cardiomyopathy and low LVEF, there exist quantifiable differences in 3-dimensional endocardial surface curvedness, LV wall thickness, and LV relative wall thickness between those with no clinical events and those with arrhythmic or heart failure outcomes, reflecting adverse LV remodeling. This retrospective study is a proof of concept to demonstrate that regional LV remodeling indices have the potential to improve the personalized risk assessment for SCD.
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Affiliation(s)
- Fijoy Vadakkumpadan
- Department of Biomedical Engineering, Institute for Computational Medicine, Johns Hopkins University, Baltimore, Maryland.
| | - Natalia Trayanova
- Department of Biomedical Engineering, Institute for Computational Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Katherine C Wu
- Division of Cardiology, Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland
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Wan X, Yan K, Luo D, Zeng Y. A combined algorithm for T-wave alternans qualitative detection and quantitative measurement. J Cardiothorac Surg 2013; 8:7. [PMID: 23311454 PMCID: PMC3554460 DOI: 10.1186/1749-8090-8-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 01/07/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND T-wave alternans (TWA) provides a noninvasive and clinically useful marker for the risk of sudden cardiac death (SCD). Current most widely used TWA detection algorithms work in two different domains: time and frequency. The disadvantage of the spectral analytical techniques is that they treat the alternans signal as a stationary wave with a constant amplitude and a phase. They cannot detect non-stationary characteristics of the signal. The temporal domain methods are sensitive to the alignment of the T-waves. In this study, we sought to develop a robust combined algorithm (CA) to assess T-wave alternans, which can qualitatively detect and quantitatively measure TWA in time domain. METHODS The T wave sequences were extracted and the total energy of each T wave within the specified time-frequency region was calculated. The rank-sum test was applied to the ranked energy sequences of T waves to detect TWA qualitatively. The ECG containing TWA was quantitatively analyzed with correlation method. RESULTS Simulation test result proved a mean sensitivity of 91.2% in detecting TWA, and for the SNR not less than 30 dB, the accuracy rate of detection achieved 100%. The clinical data experiment showed that the results from this method vs. spectral method had the correlation coefficients of 0.96. CONCLUSIONS A novel TWA analysis algorithm utilizing the wavelet transform and correlation technique is presented in this paper. TWAs are not only correctly detected qualitatively in frequency domain by energy value of T waves, but the alternans frequency and amplitude in temporal domain are measured quantitatively.
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Affiliation(s)
- XiangKui Wan
- School of Information Engineering, Guangdong University of Technology, Guangzhou, 510006, China
| | - Kanghui Yan
- School of Information Engineering, Guangdong University of Technology, Guangzhou, 510006, China
| | - Dehan Luo
- School of Information Engineering, Guangdong University of Technology, Guangzhou, 510006, China
| | - Yanjun Zeng
- Biomedical Engineering Center, Beijing University of Technology, Beijing, 100022, China
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Tereshchenko LG, Ghanem RN, Abeyratne A, Swerdlow CD. Intracardiac QT integral on far-field ICD electrogram predicts sustained ventricular tachyarrhythmias in ICD patients. Heart Rhythm 2011; 8:1889-94. [PMID: 21802390 DOI: 10.1016/j.hrthm.2011.07.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 07/23/2011] [Indexed: 10/17/2022]
Abstract
BACKGROUND Prediction of sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) could help to guide preventive interventions in at-risk patients. The QRST integral (∫QT) reflects intrinsic repolarization properties. OBJECTIVE The objective of this study was to determine whether intracardiac ∫QT predicts VT/VF in the next few months in patients with implantable cardioverter defibrillators (ICDs). METHODS Far-field (FF) and near-field (NF) right ventricular intracardiac electrograms (EGMs) were recorded via telemetry in 46 patients with structural heart disease and ICDs implanted for secondary prevention of sudden cardiac death. Epochs of 4.9 ± 0.4 minutes during sinus rhythm (mean heart rate 70.9 ± 15.2 beats/min) and ventricular pacing at 105 beats/min were analyzed. Mean ∫QT was calculated on FF and NF EGMs as the algebraic sum of areas under the QRST curve and adjusted by mean heart rate. Patients were followed up for at least 3 months. True VT/VF events treated by the ICD served as the end point. RESULTS During a mean follow-up of 4.6 months, 22 patients (48%) were treated for VT/VF. Unadjusted and adjusted by heart rate, FF EGM ∫QT in sinus rhythm was a significant predictor of VT/VF (unadjusted ∫QT hazard ratio 1.007; 95% confidence interval 1.002 to 1.0013; P = .007; adjusted ∫QT hazard ratio 1.68; 95% confidence interval 1.19 to 2.36; P = .002). The highest quartile of intracardiac ∫QT predicted VT/VF (log-rank test P = .042) and identified patients at risk with a specificity of 86% and positive predictive value of 73%. CONCLUSION Increased intracardiac FF EGM ∫QT predicts VT/VF in patients with structural heart disease and secondary prevention ICDs.
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Affiliation(s)
- Larisa G Tereshchenko
- Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, Maryland, USA.
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Morentin B, Audicana C. Estudio poblacional de la muerte súbita cardiovascular extrahospitalaria: incidencia y causas de muerte en adultos de edad mediana. Rev Esp Cardiol 2011; 64:28-34. [DOI: 10.1016/j.recesp.2010.07.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 07/20/2010] [Indexed: 11/26/2022]
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Han L, Tereshchenko LG. Lability of R- and T-wave peaks in three-dimensional electrocardiograms in implantable cardioverter defibrillator patients with ventricular tachyarrhythmia during follow-up. J Electrocardiol 2010; 43:577-82. [PMID: 20655057 DOI: 10.1016/j.jelectrocard.2010.05.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2010] [Indexed: 10/19/2022]
Abstract
INTRODUCTION From experiments, we know that the heterogeneity of action potential duration and morphology is an important mechanism of ventricular tachyarrhythmia. Electrocardiogram (ECG) markers of repolarization lability are known; however, lability of depolarization has not been systematically studied. We propose a novel method for the assessment of variability of both depolarization and repolarization phases of the cardiac cycle. METHODS Baseline orthogonal ECGs of 81 patients (mean ± SD age, 56 ± 13 years; 61 male [75%]) with structural heart disease and implanted single-chamber implantable cardioverter defibrillator (ICD) were analyzed. Clean 30-beat intervals with absence of premature beats were then selected. Baseline wandering was corrected before analysis. Peaks of R wave and peaks of T wave were detected for each beat, and the axis magnitude was calculated. The peaks were plotted to show clouds of peaks and then used to construct a convex hull, and the volumes of the R peaks cloud and T peaks cloud and ratio of volumes were calculated. RESULTS During a mean (SD) follow-up period of 13 (10) months, 9 of the 81 patients had sustained ventricular tachycardia or ventricular fibrillation (VT/VF) and received appropriate ICD therapies. All ICD events were adjudicated by three independent electrophysiologists. There was no statistically significant difference in the volume of T-wave peaks or R-wave peaks between patients with and without VT or VF during follow-up; however, R/T peaks cloud volume ratio was significantly lower in patients with subsequent VT/VF (22.4 ± 25.4 versus 13.1 ± 7.9, P = .024). CONCLUSIONS Larger volume of T peaks cloud, measured during 30 beats of three-dimensional ECG, is associated with higher risk of sustained ventricular tachyarrhythmias and appropriate ICD therapies. New method to assess temporal variability of repolarization in three-dimensional ECGs by measuring volume of peak clouds shows potential for further exploration for VT/VF risk stratification.
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Affiliation(s)
- Lichy Han
- Whiting School of Engineering, The Johns Hopkins University, Baltimore, MD 21287, USA
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