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Josephs KS, Roberts AM, Theotokis P, Walsh R, Ostrowski PJ, Edwards M, Fleming A, Thaxton C, Roberts JD, Care M, Zareba W, Adler A, Sturm AC, Tadros R, Novelli V, Owens E, Bronicki L, Jarinova O, Callewaert B, Peters S, Lumbers T, Jordan E, Asatryan B, Krishnan N, Hershberger RE, Chahal CAA, Landstrom AP, James C, McNally EM, Judge DP, van Tintelen P, Wilde A, Gollob M, Ingles J, Ware JS. Beyond gene-disease validity: capturing structured data on inheritance, allelic requirement, disease-relevant variant classes, and disease mechanism for inherited cardiac conditions. Genome Med 2023; 15:86. [PMID: 37872640 PMCID: PMC10594882 DOI: 10.1186/s13073-023-01246-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 10/12/2023] [Indexed: 10/25/2023] Open
Abstract
BACKGROUND As the availability of genomic testing grows, variant interpretation will increasingly be performed by genomic generalists, rather than domain-specific experts. Demand is rising for laboratories to accurately classify variants in inherited cardiac condition (ICC) genes, including secondary findings. METHODS We analyse evidence for inheritance patterns, allelic requirement, disease mechanism and disease-relevant variant classes for 65 ClinGen-curated ICC gene-disease pairs. We present this information for the first time in a structured dataset, CardiacG2P, and assess application in genomic variant filtering. RESULTS For 36/65 gene-disease pairs, loss of function is not an established disease mechanism, and protein truncating variants are not known to be pathogenic. Using the CardiacG2P dataset as an initial variant filter allows for efficient variant prioritisation whilst maintaining a high sensitivity for retaining pathogenic variants compared with two other variant filtering approaches. CONCLUSIONS Access to evidence-based structured data representing disease mechanism and allelic requirement aids variant filtering and analysis and is a pre-requisite for scalable genomic testing.
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Affiliation(s)
- Katherine S Josephs
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN, UK
- Royal Brompton and Harefield Hospitals, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Angharad M Roberts
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN, UK
- Great Ormond Street Hospital, NHS Foundation Trust, London, UK
| | - Pantazis Theotokis
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Roddy Walsh
- Amsterdam University Medical Centre, University of Amsterdam, Heart Center, Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | | | - Matthew Edwards
- Clinical Genetics & Genomics Lab, Royal Brompton and Harefield Hospitals, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Andrew Fleming
- Clinical Genetics & Genomics Lab, Royal Brompton and Harefield Hospitals, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Courtney Thaxton
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jason D Roberts
- Population Health Research Institute, McMaster University, and Hamilton Health Sciences, Hamilton, Ontario, Canada
| | - Melanie Care
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
- Division of Cardiology, Toronto General Hospital, Toronto, Canada
| | - Wojciech Zareba
- Clinical Cardiovascular Research Center, University of Rochester, Rochester, NY, USA
| | - Arnon Adler
- Division of Cardiology, Peter Munk Cardiac Centre, University Health Network and Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | | | - Rafik Tadros
- Cardiovascular Genetics Center, Montreal Heart Institute, and Faculty of Medicine, Université de Montréal, Montreal, Canada
| | - Valeria Novelli
- Unit of Immunology and Functional Genomics, Centro Cardiologico Monzino IRCCS, Milano, Italy
| | - Emma Owens
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Lucas Bronicki
- Department of Pathology and Laboratory Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Department of Genetics, CHEO, Ottawa, Ontario, Canada
| | - Olga Jarinova
- Department of Pathology and Laboratory Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Department of Genetics, CHEO, Ottawa, Ontario, Canada
| | - Bert Callewaert
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Stacey Peters
- Department of Cardiology and Genomic Medicine, Royal Melbourne Hospital, Melbourne, Australia
- University of Melbourne, Melbourne, Australia
| | - Tom Lumbers
- Barts Health & University College London Hospitals NHS Trusts, London, UK
- Institute of Health Informatics, University College London, London, UK
| | - Elizabeth Jordan
- Divisions of Human Genetics and Cardiovascular Medicine, The Ohio State University, Columbus, OH, USA
| | - Babken Asatryan
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Neesha Krishnan
- Centre for Population Genomics, Garvan Institute of Medical Research, and UNSW Sydney, Sydney, Australia
| | - Ray E Hershberger
- Divisions of Human Genetics and Cardiovascular Medicine, The Ohio State University, Columbus, OH, USA
| | - C Anwar A Chahal
- Center for Inherited Cardiovascular Diseases, WellSpan Health, Lancaster, PA, USA
- Cardiac Electrophysiology and Inherited Cardiovascular Diseases, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, UK
| | - Andrew P Landstrom
- Department of Pediatrics and Cell Biology, Duke University School of Medicine, Durham, NC, USA
| | - Cynthia James
- Johns Hopkins Center for Inherited Heart Diseases, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Elizabeth M McNally
- Center for Genetic Medicine, Dept of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Daniel P Judge
- Medical University of South Carolina, Charleston, SC, USA
| | - Peter van Tintelen
- Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Arthur Wilde
- Department of Cardiology, Amsterdam UMC location University of Amsterdam, Meibergdreef 9, Amsterdam, the Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam UMC location University of Amsterdam, Amsterdam, the Netherlands
| | - Michael Gollob
- Inherited Arrhythmia and Cardiomyopathy Program, Division of Cardiology, University of Toronto, Toronto, ON, Canada
| | - Jodie Ingles
- Centre for Population Genomics, Garvan Institute of Medical Research, and UNSW Sydney, Sydney, Australia
| | - James S Ware
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN, UK.
- Royal Brompton and Harefield Hospitals, Guy's and St Thomas' NHS Foundation Trust, London, UK.
- MRC London Institute of Medical Sciences, Imperial College London, London, UK.
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Josephs KS, Roberts AM, Theotokis P, Walsh R, Ostrowski PJ, Edwards M, Fleming A, Thaxton C, Roberts JD, Care M, Zareba W, Adler A, Sturm AC, Tadros R, Novelli V, Owens E, Bronicki L, Jarinova O, Callewaert B, Peters S, Lumbers T, Jordan E, Asatryan B, Krishnan N, Hershberger RE, Chahal CAA, Landstrom AP, James C, McNally EM, Judge DP, van Tintelen P, Wilde A, Gollob M, Ingles J, Ware JS. Beyond gene-disease validity: capturing structured data on inheritance, allelic-requirement, disease-relevant variant classes, and disease mechanism for inherited cardiac conditions. medRxiv 2023:2023.04.03.23287612. [PMID: 37066275 PMCID: PMC10104233 DOI: 10.1101/2023.04.03.23287612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Background As availability of genomic testing grows, variant interpretation will increasingly be performed by genomic generalists, rather than domain-specific experts. Demand is rising for laboratories to accurately classify variants in inherited cardiac condition (ICC) genes, including as secondary findings. Methods We analyse evidence for inheritance patterns, allelic requirement, disease mechanism and disease-relevant variant classes for 65 ClinGen-curated ICC gene-disease pairs. We present this information for the first time in a structured dataset, CardiacG2P, and assess application in genomic variant filtering. Results For 36/65 gene-disease pairs, loss-of-function is not an established disease mechanism, and protein truncating variants are not known to be pathogenic. Using CardiacG2P as an initial variant filter allows for efficient variant prioritisation whilst maintaining a high sensitivity for retaining pathogenic variants compared with two other variant filtering approaches. Conclusions Access to evidence-based structured data representing disease mechanism and allelic requirement aids variant filtering and analysis and is pre-requisite for scalable genomic testing.
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Affiliation(s)
- Katherine S Josephs
- National Heart and Lung Institute, Imperial College London, London, UK
- Royal Brompton and Harefield Hospitals, Guy's and St Thomas' NHS Foundation Trust, London UK
| | - Angharad M Roberts
- National Heart and Lung Institute, Imperial College London, London, UK
- Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | | | - Roddy Walsh
- Amsterdam University Medical Centre, University of Amsterdam, Heart Center, Department of Experimental Cardiology, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | | | - Matthew Edwards
- Clinical Genetics & Genomics Lab, Royal Brompton and Harefield Hospitals, Guy's and St Thomas' NHS Foundation Trust, London UK
| | - Andrew Fleming
- Clinical Genetics & Genomics Lab, Royal Brompton and Harefield Hospitals, Guy's and St Thomas' NHS Foundation Trust, London UK
| | - Courtney Thaxton
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jason D Roberts
- Population Health Research Institute, McMaster University, and Hamilton Health Sciences, Hamilton, Ontario, Canada
| | - Melanie Care
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
- Division of Cardiology, Toronto General Hospital, Toronto, Canada
| | - Wojciech Zareba
- Clinical Cardiovascular Research Center, University of Rochester, Rochester, New York, USA
| | - Arnon Adler
- Division of Cardiology, Peter Munk Cardiac Centre, University Health Network and Department of Medicine, University of Toronto, Toronto, ON, Canada
| | - Amy C Sturm
- 23andMe, Sunnyvale, California, Genomic Health
| | - Rafik Tadros
- Cardiovascular Genetics Center, Montreal Heart Institute, and Faculty of Medicine, Université de Montréal
| | - Valeria Novelli
- Unit of Immunology and Functional Genomics, Centro Cardiologico Monzino IRCCS, Milano, Italy
| | - Emma Owens
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Lucas Bronicki
- CHEO Research Institute, University of Ottawa, Ontario, Canada
| | - Olga Jarinova
- CHEO Research Institute, University of Ottawa, Ontario, Canada
- Department of Genetics, CHEO, Ontario, Canada
| | - Bert Callewaert
- Center for Medical Genetics, Ghent University Hospital
- Department of Biomolecular Medicine, Ghent University
| | - Stacey Peters
- Department of Cardiology and Genomic Medicine, Royal Melbourne Hospital, Melbourne, Australia
- University of Melbourne, Melbourne, Australia
| | - Tom Lumbers
- Barts Health & University College London Hospitals NHS Trusts, London, UK
- Institute of Health Informatics, University College London, London, UK
| | - Elizabeth Jordan
- Division of Human Genetics, The Ohio State University, Columbus, Ohio USA
| | - Babken Asatryan
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Neesha Krishnan
- Centre for Population Genomics, Garvan Institute of Medical Research, and UNSW Sydney, Sydney, Australia
| | - Ray E Hershberger
- Division of Human Genetics, The Ohio State University, Columbus, Ohio USA
| | - C Anwar A Chahal
- Center for Inherited Cardiovascular Diseases, WellSpan Health, Lancaster, PA USA
- Cardiac Electrophysiology and Inherited Cardiovascular Diseases, Cardiovascular Division, Hospital of the University of Pennsylvania, Philadelphia, PA USA
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN USA
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, UK
| | - Andrew P Landstrom
- Department of Pediatrics and Cell Biology, Duke University School of Medicine, Durham, North Carolina, US
| | - Cynthia James
- Johns Hopkins Center for Inherited Heart Diseases, Department of Medicine, Johns Hopkins
| | - Elizabeth M McNally
- Center for Genetic Medicine, Dept of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, IL US
| | - Daniel P Judge
- Medical University of South Carolina, Charleston, SC USA
| | - Peter van Tintelen
- Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Arthur Wilde
- Amsterdam UMC location University of Amsterdam, Department of Cardiology, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam Cardiovascular Sciences, Heart Failure and arrhythmias, Amsterdam, the Netherlands
| | - Michael Gollob
- Inherited Arrhythmia and Cardiomyopathy Program, Division of Cardiology, University of Toronto, Toronto ON Canada
| | - Jodie Ingles
- Centre for Population Genomics, Garvan Institute of Medical Research, and UNSW Sydney, Sydney, Australia
| | - James S Ware
- National Heart and Lung Institute, Imperial College London, London, UK
- Royal Brompton and Harefield Hospitals, Guy's and St Thomas' NHS Foundation Trust, London UK
- MRC London Institute of Medical Sciences, Imperial College London, London, UK
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Alzoughool F, Al-Zghoul MB, Ghanim BY, Gollob M, Idkaidek N, Qinna NA. The Role of Interventional Irisin on Heart Molecular Physiology. Pharmaceuticals (Basel) 2022; 15:ph15070863. [PMID: 35890161 PMCID: PMC9319709 DOI: 10.3390/ph15070863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/04/2022] [Accepted: 07/11/2022] [Indexed: 12/14/2022] Open
Abstract
Irisin, encoded by the FNDC5 (fibronectin type III domain containing 5) gene, is a novel myokine that has been implicated as an essential mediator of exercise benefits. Effects of irisin on heart physiology is still ambiguous. This study aimed to evaluate the impact of exogenous administration of irisin on heart physiology and the pharmacokinetic profile of pump-administered irisin. To do so, Sprague Dawley rats were implanted with an irisin-loaded osmotic pump (5 μg/kg/day) for 42 days, and other animals were administered with single bolus subcutaneous injections of irisin (5 µg/kg). Body weights and blood samples were collected weekly for 42 days for serum irisin quantification and histopathology. Clinical biochemistry analyses were performed. Heart mRNA expression was assessed in 26 selected genes. Chronic interventional exogenous irisin significantly reduced body weight without affecting the heart myocyte size and significantly reduced creatine kinase enzyme level. Blood CBC, serum biochemistry, and heart morphology were normal. Gene expression of FNCD5, Raf1, CPT1, IGF-1, and CALCIN, encoding for heart physiology, increased while PGC1, Nox4, and Mfn1 significantly decreased. Nevertheless, irisin increased the expression of cardioprotective genes and inhibited some genes that harm heart physiology. Administration of irisin promotes myocardial functions and could be translated into clinical settings after preclinical profiling.
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Affiliation(s)
- Foad Alzoughool
- Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, The Hashemite University, Zarqa 13133, Jordan;
- Faculty of Health Sciences, Higher Colleges of Technology, Fujairah Women’s College, Fujairah P.O. Box. 25026, United Arab Emirates
| | - Mohammad Borhan Al-Zghoul
- Basic Veterinary Sciences, School of Veterinary Medicine, Jordan University of Science and Technology, Irbid 22110, Jordan;
| | - Bayan Y. Ghanim
- University of Petra Pharmaceutical Center (UPPC), University of Petra, Amman 11196, Jordan;
| | - Michael Gollob
- Peter Munk Cardiac Centre, Toronto General Hospital, University of Toronto, Toronto, ON M5G 2N2, Canada;
| | - Nasir Idkaidek
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy and Medical Sciences, University of Petra, Amman 11196, Jordan;
| | - Nidal A. Qinna
- University of Petra Pharmaceutical Center (UPPC), University of Petra, Amman 11196, Jordan;
- Department of Pharmacology and Biomedical Sciences, Faculty of Pharmacy and Medical Sciences, University of Petra, Amman 11196, Jordan
- Correspondence:
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Liao S, Bokhari M, Chakraborty P, Suszko A, Jones G, Spears D, Gollob M, Zhang Z, Wang B, Chauhan VS. Use of Wearable Technology and Deep Learning to Improve the Diagnosis of Brugada Syndrome. JACC Clin Electrophysiol 2022; 8:1010-1020. [DOI: 10.1016/j.jacep.2022.05.003] [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] [Received: 01/13/2022] [Revised: 03/28/2022] [Accepted: 05/04/2022] [Indexed: 10/17/2022]
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Liu J, Bayer JD, Aschar-Sobbi R, Wauchop M, Spears D, Gollob M, Vigmond EJ, Tsushima R, Backx PH, Chauhan VS. Complex interactions in a novel SCN5A compound mutation associated with long QT and Brugada syndrome: Implications for Na+ channel blocking pharmacotherapy for de novo conduction disease. PLoS One 2018; 13:e0197273. [PMID: 29791480 PMCID: PMC5965851 DOI: 10.1371/journal.pone.0197273] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 04/30/2018] [Indexed: 11/29/2022] Open
Abstract
Background The SCN5A mutation, P1332L, is linked to a malignant form of congenital long QT syndrome, type 3 (LQT3), and affected patients are highly responsive to the Na+ channel blocking drug, mexiletine. In contrast, A647D is an atypical SCN5A mutation causing Brugada syndrome. An asymptomatic male with both P1332L and A647D presented with varying P wave/QRS aberrancy and mild QTc prolongation which did not shorten measurably with mexiletine. Objective We characterized the biophysical properties of P1332L, A647D and wild-type (WT) Na+ channels as well as their combinations in order to understand our proband’s phenotype and to guide mexilitine therapy. Methods Na+ channel biophysics and mexilitine-binding kinetics were assessed using heterologous expression studies in CHO-K1 cells and human ventricular myocyte modeling. Results Compared to WT, P1332L channels displayed a hyperpolarizing shift in inactivation, slower inactivation and prominent late Na+ currents (INa). While A647D had no effect on the biophysical properties of INa, it reduced peak and late INa density when co-expressed with either WT or P1332L. Additionally, while P1332L channels had greater sensitivity to block by mexiletine compared to WT, this was reduced in the presence of A647D. Modelling studies revealed that mixing P1332L with A647D channels, action potential durations were shortened compared to P1332L, while peak INa was reduced compared to either A647D coexpressing with WT or WT alone. Conclusions While A647D mitigates the lethal LQT3 phenotype seen with P1332L, it also reduces mexilitine sensitivity and decreases INa density. These results explain our proband’s mild repolarization abnormality and prominent conduction defect in the atria and ventricles, but also suggest that expression of P1332L with A647D yields a novel disease phenotype for which mexiletine pharmacotherapy is no longer suitable.
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Affiliation(s)
- Jie Liu
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Jason D. Bayer
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University Foundation, Pessac, France
- University of Bordeaux, IMB, UMR 5251, Talance, France
| | | | - Marianne Wauchop
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Danna Spears
- Peter Munk Cardiac Center, Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Michael Gollob
- Peter Munk Cardiac Center, Division of Cardiology, University Health Network, Toronto, Ontario, Canada
| | - Edward J. Vigmond
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University Foundation, Pessac, France
- University of Bordeaux, IMB, UMR 5251, Talance, France
| | - Robert Tsushima
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Peter H. Backx
- Department of Biology, York University, Toronto, Ontario, Canada
- Peter Munk Cardiac Center, Division of Cardiology, University Health Network, Toronto, Ontario, Canada
- * E-mail: (PB); (VC)
| | - Vijay S. Chauhan
- Peter Munk Cardiac Center, Division of Cardiology, University Health Network, Toronto, Ontario, Canada
- * E-mail: (PB); (VC)
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Viswanathan K, Suszko AM, DAS M, Jackson N, Gollob M, Cameron D, Spears D, Woo A, Rakowski H, Khurana M, Chauhan VS. Rapid Device-Detected Nonsustained Ventricular Tachycardia in the Risk Stratification of Hypertrophic Cardiomyopathy. Pacing Clin Electrophysiol 2016; 39:642-51. [PMID: 27027856 DOI: 10.1111/pace.12861] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 03/03/2016] [Accepted: 03/19/2016] [Indexed: 01/07/2023]
Abstract
BACKGROUND Nonsustained ventricular tachycardia (NSVT) detected by ambulatory Holter (Holter NSVT) is a major risk factor for sudden cardiac death in hypertrophic cardiomyopathy (HCM). We hypothesized that the prognostic utility of Holter NSVT in HCM would improve with prolonged monitoring and a higher heart rate cut-off for detection. METHODS We enrolled 60 patients (44 ± 14 years) with HCM, who had a prophylactic implantable cardioverter defibrillator (ICD). Positive Holter NSVT (prior to implant) was defined as ≥3 beats at ≥120 beats per minute (bpm). We assessed the prevalence of rapid NSVT (RNSVT) detected by their ICD within 12 months of its implant, defined as 4-16 beats at ≥150-200 bpm. The primary outcome was appropriate ICD therapy (antitachycardia pacing and shocks) for sustained ventricular arrhythmia (VA). RESULTS Holter NSVT was detected in 34 patients. RNSVT occurred in 21 (35%) patients of whom five did not have Holter NSVT. Over a median follow-up of 61 (interquartile range 29, 129) months after ICD implant, nine patients had VA. RNSVT, but not Holter NSVT, was significantly associated with VA (hazard ratio 6.2, 95% confidence interval [1.3-30], P = 0.01) by multivariable Cox regression analysis that included conventional risk factors. Receiver operating characteristic analysis for RNSVT (area under curve 0.80, P = 0.005) showed that the occurrence of ≥2 episodes of RNSVT discriminated patients for VA optimally (sensitivity 78%, specificity 84%, positive predictive value 47%, negative predictive value 96%). CONCLUSIONS In this pilot study, RNSVT detected by continuous monitoring independently predicted VA in HCM and offered superior discrimination of VA risk compared to conventional risk factors, including Holter NSVT. Future studies are needed to validate these findings in a larger, unselected HCM cohort.
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Affiliation(s)
- Karthik Viswanathan
- Division of Cardiology, Peter Munk Cardiac Center, University Health Network, Toronto, Canada
| | - Adrian M Suszko
- Division of Cardiology, Peter Munk Cardiac Center, University Health Network, Toronto, Canada
| | - Moloy DAS
- Division of Cardiology, Peter Munk Cardiac Center, University Health Network, Toronto, Canada
| | - Nicholas Jackson
- Division of Cardiology, Peter Munk Cardiac Center, University Health Network, Toronto, Canada
| | - Michael Gollob
- Division of Cardiology, Peter Munk Cardiac Center, University Health Network, Toronto, Canada
| | - Douglas Cameron
- Division of Cardiology, Peter Munk Cardiac Center, University Health Network, Toronto, Canada
| | - Danna Spears
- Division of Cardiology, Peter Munk Cardiac Center, University Health Network, Toronto, Canada
| | - Anna Woo
- Division of Cardiology, Peter Munk Cardiac Center, University Health Network, Toronto, Canada
| | - Harry Rakowski
- Division of Cardiology, Peter Munk Cardiac Center, University Health Network, Toronto, Canada
| | - Mamta Khurana
- Division of Cardiology, Peter Munk Cardiac Center, University Health Network, Toronto, Canada
| | - Vijay S Chauhan
- Division of Cardiology, Peter Munk Cardiac Center, University Health Network, Toronto, Canada
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Hu D, Zhang J, Li Y, Pfeiffer R, Gollob M, Healey J, Harrell DT, Makita N, Abe H, Sun Y, Guo J, Zhang L, Yan G, Mah D, Walsh E, Leopold H, Giustetto C, Gaita F, Mazzanti A, Priori S, Antzelevitch C, Martinez HB. THE PHENOTYPIC SPECTRUM OF MOST FREQUENT MUTATION RESPONSIBLE FOR THE SHORT QT SYNDROME. J Am Coll Cardiol 2016. [DOI: 10.1016/s0735-1097(16)30677-5] [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: 11/24/2022]
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Porta-Sanchez A, Alqubbany A, Das M, Downar E, Masse S, Harris L, Cameron D, Nair K, Chauhan V, Spears D, Ha A, Gollob M, Jackson N, Nanthakumar K. USING TIMING RELATIONSHIPS OF SINGLE DIASTOLIC ELECTROGRAMS DURING RAPID ACTIVATION MAPPING TO DETERMINE CRITICAL SITE DURING VENTRICULAR TACHYCARDIA ABLATION. Can J Cardiol 2015. [DOI: 10.1016/j.cjca.2015.07.600] [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: 11/24/2022] Open
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9
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Roeske C, Martinuk A, Choudhry A, Hendy GN, Gollob M, Li Q, Georgalis T, de Bold AJ. Go protein subunit Goα and the secretory process of the natriuretic peptide hormones ANF and BNP. J Mol Endocrinol 2015; 54:277-88. [PMID: 25917834 DOI: 10.1530/jme-15-0081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/24/2015] [Indexed: 12/31/2022]
Abstract
Expression of the G protein subunit Goα has been shown to be prominent in the atria of the rat heart and to be significantly associated with atrial natriuretic factor (ANF)-containing atrial-specific secretory granules by immunocytochemistry. In addition, differential expression profile analysis using oligonucleotide arrays has shown that the Goα isoform 1 (Goα1) is 2.3-fold more abundant in the atria than it is in the ventricles. In the present report, we show protein-protein interaction between Goα and ANF by yeast two-hybrid and by immunoprecipitation. A cardiac conditional Goα knockout model developed for the present study showed a 90% decrease in Goα expression and decreased atrial expression and ANF and brain natriuretic peptides (BNP) content. Expression of chromogranin A, a specific atrial granule core constituent, was not affected. Morphometric assessment of atrial tissue showed a very significant decrease in atrial-specific granule density as well as granule core electron density. Atrial electrical activity was not affected. The results obtained are compatible with the suggestion that Goα plays a role in ANF sorting during intracellular vectorial transport and with the presence of a mechanism that preserves the molar relationship between cellular ANF and BNP stores in the face of the decreased production of these hormones.
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Affiliation(s)
- Cassandra Roeske
- Cardiovascular Endocrinology LaboratoryUniversity of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario, Canada K1Y 4W7Department of Pathology and Laboratory MedicineFaculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5Experimental Therapeutics and MetabolismMcGill University Health Centre-Research Institute, and Departments of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec, CanadaToronto General Hospital200 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4
| | - Amy Martinuk
- Cardiovascular Endocrinology LaboratoryUniversity of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario, Canada K1Y 4W7Department of Pathology and Laboratory MedicineFaculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5Experimental Therapeutics and MetabolismMcGill University Health Centre-Research Institute, and Departments of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec, CanadaToronto General Hospital200 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4
| | - Asna Choudhry
- Cardiovascular Endocrinology LaboratoryUniversity of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario, Canada K1Y 4W7Department of Pathology and Laboratory MedicineFaculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5Experimental Therapeutics and MetabolismMcGill University Health Centre-Research Institute, and Departments of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec, CanadaToronto General Hospital200 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4
| | - Geoffrey N Hendy
- Cardiovascular Endocrinology LaboratoryUniversity of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario, Canada K1Y 4W7Department of Pathology and Laboratory MedicineFaculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5Experimental Therapeutics and MetabolismMcGill University Health Centre-Research Institute, and Departments of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec, CanadaToronto General Hospital200 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4
| | - Michael Gollob
- Cardiovascular Endocrinology LaboratoryUniversity of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario, Canada K1Y 4W7Department of Pathology and Laboratory MedicineFaculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5Experimental Therapeutics and MetabolismMcGill University Health Centre-Research Institute, and Departments of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec, CanadaToronto General Hospital200 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4
| | - Qiuji Li
- Cardiovascular Endocrinology LaboratoryUniversity of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario, Canada K1Y 4W7Department of Pathology and Laboratory MedicineFaculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5Experimental Therapeutics and MetabolismMcGill University Health Centre-Research Institute, and Departments of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec, CanadaToronto General Hospital200 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4
| | - Tina Georgalis
- Cardiovascular Endocrinology LaboratoryUniversity of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario, Canada K1Y 4W7Department of Pathology and Laboratory MedicineFaculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5Experimental Therapeutics and MetabolismMcGill University Health Centre-Research Institute, and Departments of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec, CanadaToronto General Hospital200 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4
| | - Adolfo J de Bold
- Cardiovascular Endocrinology LaboratoryUniversity of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario, Canada K1Y 4W7Department of Pathology and Laboratory MedicineFaculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5Experimental Therapeutics and MetabolismMcGill University Health Centre-Research Institute, and Departments of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec, CanadaToronto General Hospital200 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4 Cardiovascular Endocrinology LaboratoryUniversity of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario, Canada K1Y 4W7Department of Pathology and Laboratory MedicineFaculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5Experimental Therapeutics and MetabolismMcGill University Health Centre-Research Institute, and Departments of Medicine, Physiology and Human Genetics, McGill University, Montreal, Quebec, CanadaToronto General Hospital200 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4
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10
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Xi Y, Honeywell C, Zhang D, Schwartzentruber J, Beaulieu CL, Tetreault M, Hartley T, Marton J, Vidal SM, Majewski J, Aravind L, Gollob M, Boycott KM, Gow RM. Whole exome sequencing identifies the TNNI3K gene as a cause of familial conduction system disease and congenital junctional ectopic tachycardia. Int J Cardiol 2015; 185:114-6. [PMID: 25791106 DOI: 10.1016/j.ijcard.2015.03.130] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Accepted: 03/07/2015] [Indexed: 12/20/2022]
Affiliation(s)
- Yanwei Xi
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Christina Honeywell
- Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Dapeng Zhang
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
| | | | - Chandree L Beaulieu
- Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Martine Tetreault
- McGill University and Genome Quebec Innovation Centre, Montreal, Quebec, Canada; Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Taila Hartley
- Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Jennifer Marton
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Silvia M Vidal
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Jacek Majewski
- McGill University and Genome Quebec Innovation Centre, Montreal, Quebec, Canada; Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - L Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
| | | | - Michael Gollob
- Toronto General Hospital, Department of Cardiology, University of Toronto, Toronto, Ontario, Canada
| | - Kym M Boycott
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario, Canada; Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.
| | - Robert M Gow
- Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.
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Thorn SL, deKemp R, Dumouchel T, Klein R, Renaud JN, Wells RG, Gollob M, Beanlands RS, DaSilva JN. Reply: Noninvasive Measurement of Mouse Myocardial Glucose Uptake with 18F-FDG. J Nucl Med 2014; 55:866-7. [DOI: 10.2967/jnumed.114.138214] [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: 11/16/2022] Open
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12
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Affiliation(s)
- Eduardo Back Sternick
- Faculdade de Ciências Médicas de Minas Gerais, Hospital Universitário São José, Belo Horizonte, Brazil
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13
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So PP, Healey J, Chauhan V, Birnie D, Champagne J, Sanatani S, Ahmad K, Ballantyne E, Gerull B, Yee R, Skanes A, Gula L, Leong-Sit P, Klein G, Gollob M, Simpson C, Talajic M, Gardner M, Krahn AD. Systematic Assessment of Patients With Unexplained Syncope and Polymorphic Ventricular Tachycardia in the Cardiac Arrest Survivors With Preserved Ejection Fraction Registry (CASPER). Can J Cardiol 2013. [DOI: 10.1016/j.cjca.2013.07.189] [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: 10/26/2022] Open
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14
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Garg N, Roberts J, Wells G, Labinaz M, Le May M, Glover C, Froeschl M, Dick A, Marquis J, Gollob M, McPherson R, So D. 298 Influence Of Genetic Polymorphisms In Combination With Clinical Variables On High On-Clopidogrel Platelet Reactivity In Patients Undergoing Percutaneous Coronary Intervention. Can J Cardiol 2012. [DOI: 10.1016/j.cjca.2012.07.280] [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: 11/24/2022] Open
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15
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Ackerman MJ, Priori SG, Willems S, Berul C, Brugada R, Calkins H, Camm AJ, Ellinor PT, Gollob M, Hamilton R, Hershberger RE, Judge DP, Le Marec H, McKenna WJ, Schulze-Bahr E, Semsarian C, Towbin JA, Watkins H, Wilde A, Wolpert C, Zipes DP. Corrigendum to: 'HRS/EHRA Expert Consensus Statement on the State of Genetic Testing for the Channelopathies and Cardiomyopathies' [Europace 2011;13:1077-109, doi: 10.1093/europace/eur245]. Europace 2012. [DOI: 10.1093/europace/eur413] [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: 11/14/2022] Open
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16
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Ackerman MJ, Priori SG, Willems S, Berul C, Brugada R, Calkins H, Camm AJ, Ellinor PT, Gollob M, Hamilton R, Hershberger RE, Judge DP, Le Marec H, McKenna WJ, Schulze-Bahr E, Semsarian C, Towbin JA, Watkins H, Wilde A, Wolpert C, Zipes DP. HRS/EHRA expert consensus statement on the state of genetic testing for the channelopathies and cardiomyopathies this document was developed as a partnership between the Heart Rhythm Society (HRS) and the European Heart Rhythm Association (EHRA). Heart Rhythm 2012; 8:1308-39. [PMID: 21787999 DOI: 10.1016/j.hrthm.2011.05.020] [Citation(s) in RCA: 724] [Impact Index Per Article: 60.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Indexed: 10/18/2022]
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17
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Ackerman MJ, Priori SG, Willems S, Berul C, Brugada R, Calkins H, Camm AJ, Ellinor PT, Gollob M, Hamilton R, Hershberger RE, Judge DP, Le Marec H, McKenna WJ, Schulze-Bahr E, Semsarian C, Towbin JA, Watkins H, Wilde A, Wolpert C, Zipes DP. HRS/EHRA expert consensus statement on the state of genetic testing for the channelopathies and cardiomyopathies: this document was developed as a partnership between the Heart Rhythm Society (HRS) and the European Heart Rhythm Association (EHRA). Europace 2011; 13:1077-109. [PMID: 21810866 DOI: 10.1093/europace/eur245] [Citation(s) in RCA: 560] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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18
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Thorn S, DaSilva J, deKemp R, Moffat C, Renaud J, Klein R, Beanlands R, Harper M, Gollob M. 178 Abnormal Neonate Cardiomyocyte Metabolism is Associated with Alterations in Adult Cardiac Metabolism in a Mouse Model of the Arg302gln-prkag2 Cardiac Syndrome. Can J Cardiol 2011. [DOI: 10.1016/j.cjca.2011.07.125] [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: 10/16/2022] Open
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19
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Birnie D, Healey J, Gardner M, Chauhan V, Champage J, Sanatani S, Ahmed K, Yee R, Skanes A, Gula L, Leong-Sit P, Klein G, Gollob M, Simpson C, Krahn A. 443 Role of electro-anatomical mapping of the right ventricle in evaluation of patients with unexplained cardiac arrest and familial sudden death. Can J Cardiol 2011. [DOI: 10.1016/j.cjca.2011.07.375] [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: 11/17/2022] Open
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20
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Gardner M, Healey J, Simpson C, Chauhan V, Birnie D, Champagne J, Sanatani S, Chakrabarti S, Gula L, Ahmad K, Gollob M, Krahn A. 445 Discovering heart disease in first degree relatives of sudden death victims: A preliminary report from the casper registry. Can J Cardiol 2011. [DOI: 10.1016/j.cjca.2011.07.377] [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: 11/16/2022] Open
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21
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Redpath C, Sambell C, Stiell I, Johansen H, Williams K, Samie R, Green M, Gollob M, Lemery R, Birnie D. In-hospital mortality in 13,263 survivors of out-of-hospital cardiac arrest in Canada. Am Heart J 2010; 159:577-583.e1. [PMID: 20362715 DOI: 10.1016/j.ahj.2009.12.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [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] [Received: 07/04/2009] [Accepted: 12/14/2009] [Indexed: 11/17/2022]
Abstract
BACKGROUND There is a substantial mortality rate in patients admitted alive after out-of-hospital cardiac arrest. The primary objective of our study was to examine trends in in-hospital survival in out-of-hospital cardiac arrest survivors in Canada between 1994 and 2004. The secondary objective was to examine predictors of in-hospital survival in these patients. METHODS Data on hospital admissions from April 1, 1994, to March 31, 2004, were obtained from the Health Person-oriented Information Database, maintained by Statistics Canada. We included all patients with a primary diagnosis of cardiac arrest who survived to hospital admission. We assessed survival to hospital discharge in all patients admitted alive. RESULTS In Canada, 13,263 patients survived community arrest between 1994 and 2004. The annual incidence of hospital admission after out-of-hospital cardiac arrest decreased by 33%, from 5.37 per 100,000 in 1994 to 3.63 per 100,000 in 2004 (P < .0001 for trend). Subsequently, 5,045 patients (38.03%) survived to hospital discharge. The survival rate did not change during the duration of the study. Invasive coronary artery disease management was associated with a greatly increased chance of survival (odds ratio 21.98, 95% CI 17.62-27.42). Also male gender, heart failure, and acute myocardial ischemia were independent positive predictors of survival to hospital discharge; greater age and comorbidities were negative predictors of survival. Finally, there were significant interprovincial variations in survival rates. CONCLUSIONS Our study, the largest of its kind, has 4 main findings. Firstly, between 1993 and 2004, there was a significant and steady decline in admission rates after community cardiac arrest. Second, there was no change in the in-hospital survival rates. Thirdly, invasive management of coronary artery disease was associated with a greatly improved chance of survival, and finally, there were important regional variations in survival rates.
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Affiliation(s)
- Calum Redpath
- University of Ottawa Heart Institute, Ottawa, Ontario, Canada
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Farwell D, Redpath C, Birnie D, Gollob M, Lemery R, Posan E, Green M. Inappropriate implantable cardioverter defibrillator shocks in fractured Sprint Fidelis leads associated with 'appropriate' interrogation. Europace 2008; 10:726-8. [DOI: 10.1093/europace/eun113] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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23
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Lemery R, Birnie D, Tang ASL, Green M, Gollob M, Hendry M, Lau E. Normal Atrial Activation and Voltage During Sinus Rhythm in the Human Heart: An Endocardial and Epicardial Mapping Study in Patients with a History of Atrial Fibrillation. J Cardiovasc Electrophysiol 2007; 18:402-8. [PMID: 17394455 DOI: 10.1111/j.1540-8167.2007.00762.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [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
BACKGROUND The three-dimensional contributions to human atrial activation in sinus rhythm have not been specifically characterized. We evaluated the sequence of endocardial and epicardial activation and voltage of the atria during normal sinus rhythm. METHODS AND RESULTS The study group includes 35 patients with history of symptomatic atrial fibrillation. Prior to catheter ablation of atrial fibrillation, we performed multielectrode electroanatomic mapping during sinus rhythm, endocardially of the RA, LA, and coronary sinus (CS) and, in 10 patients, epicardially of the transverse sinus and oblique sinus. Following activation of the atrial region of the sinus node, the epicardial transverse sinus was activated 11 +/- 18 msec later, while the earliest endocardial LA activation occurred in the region of Bachmann's bundle at 31 +/- 13 msec, significantly earlier than the earliest epicardial LA activation of the oblique sinus at 54 +/- 10 msec (P < 0.002). The posterior LA revealed complex types of activation in 66% of patients analyzed, due to the convergence of wavefront propagation from the CS, oblique sinus, and endocardial LA. Bipolar voltage measurements revealed significantly higher values for the epicardium (mean 3.05 +/- 1.31 mv) than for the endocardium (mean 1.65 +/- 0.75 mv), P < 0.0001 between both groups. CONCLUSIONS In sinus rhythm, we have characterized endocardial and epicardial atrial activation and voltage, and provide an analysis and understanding of the genesis of the P wave complex in humans.
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Affiliation(s)
- Robert Lemery
- Division of Cardiology, University of Ottawa Heart Institute, Ottawa, ON, Canada.
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24
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Abstract
The terminology and technology of molecular genetics and recombinant DNA have become an essential part of academic cardiology and will soon be applied at the bedside. The treatise includes a brief summary of the essentials of the DNA molecule, the more common techniques, and their application to genetics and molecular cardiology. It is written to be understood by physicians, scientists, and paramedical personnel who would not necessarily have a background in molecular biology. Inherent in the DNA molecule are three properties fundamental to all of the diagnostic and therapeutic applications, namely, the ability of DNA to separate into single strands, recombine (annealment or hybridization), and the presence of the negative charge enables DNA fragments to be separated easily by electrophoresis. Genetic linkage analysis of a family with an inherited disease enables one to identify the gene without knowing its protein product. Over 50 diseases in cardiology due to single-gene disorders have been identified and multiple mutations have been detected. The new therapeutic frontier will be stem cells and nuclear transfer. Identification of genes responsible for coronary artery disease made possible by genome-wide single nucleotide polymorphism (SNP) mapping techniques paves the way for personalized medicine.
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25
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Green M, Gollob M. Comment on "Familial pseudo-Wolff-Parkinson-White syndrome". J Cardiovasc Electrophysiol 2006; 17:E9; author reply E10. [PMID: 17096658 DOI: 10.1111/j.1540-8167.2006.00650.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 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: 11/30/2022]
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26
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Birnie D, Williams K, Guo A, Mielniczuk L, Davis D, Lemery R, Green M, Gollob M, Tang A. Reasons for escalating pacemaker implants. Am J Cardiol 2006; 98:93-7. [PMID: 16784928 DOI: 10.1016/j.amjcard.2006.01.069] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [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] [Received: 12/12/2005] [Revised: 01/11/2006] [Accepted: 01/11/2006] [Indexed: 11/15/2022]
Abstract
Surveys of pacing practice have shown a steady increase in pacemaker implantation rates in the past 15 years, despite no major changes in United States guidelines for permanent pacing. There are no data to explain why this is occurring. In this study, records were extracted from the National Hospital Discharge Survey to investigate this. There were 3 major findings. First, age-adjusted implantation rates increased progressively over the study period from 370 per million in 1990 to 612 per million in 2002. Second, it was found that the escalating implantation rate is attributable to increasing implantation for isolated sinus node dysfunction (SND). Implantation for SND increased significantly over the study period (by 102%), whereas implantation for all other indications did not. The increasing implantation for SND is due primarily to the increasing prevalence of SND, with a lesser increase in implantation rate relative to prevalence rate. The third major finding of this study is that there has been a progressive relative and absolute increase in the dual-chamber implantation rate. In 2002, 82.8% of all initial pacemaker implantations were dual-chamber devices. Furthermore, the National Hospital Discharge Survey data indicate that the major randomized pacing trials seem to have had no impact on pacing practice in the United States. In conclusion, age-adjusted implantation rates increased progressively over the study period. This escalating implantation rate is primarily attributable to increasing implantation for SND.
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Affiliation(s)
- David Birnie
- University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
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27
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Abstract
PURPOSE OF REVIEW Atrial fibrillation is the most common clinical arrhythmia. Current treatment strategies are far from optimal. One new research direction is to target the atrial fibrillation substrate and to examine whether drugs can produce atrial structural and/or electrophysiological remodeling and whether this results in a reduction in atrial fibrillation burden. RECENT FINDINGS Two prospective randomized studies have shown that the addition of an angiotensin converting enzyme inhibitor or an angiotensin receptor blocker to amiodarone reduces the recurrence rate of atrial fibrillation after electrical cardioversion. There are ten completed prospective clinical trials with atrial fibrillation as a secondary endpoint or assessed in post-hoc analysis. Five of these studies have reported a positive impact of angiotensin converting enzyme inhibitors or angiotensin receptor blockers on atrial fibrillation burden. A meta-analysis showed that active drugs reduced the overall risk of development of atrial fibrillation by 28%. Patients in the heart failure trials obtained most benefit from these drugs (relative risk reduction 44%, P = 0.07). SUMMARY The initial basic science and clinical trial data suggest that modulation of the renin angiotensin system may be an effective treatment for atrial fibrillation. The following, however, remain to be clarified: do these drugs have a clinically meaningful impact on atrial fibrillation burden; if there is an impact, is it similar in all atrial fibrillation patients or just in certain subsets; do angiotensin converting enzyme inhibitors and angiotensin receptor blockers have similar benefits; and is there a role for aldosterone antagonists?
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Lemery R, Birnie D, Tang ASL, Green M, Gollob M. Feasibility study of endocardial mapping of ganglionated plexuses during catheter ablation of atrial fibrillation. Heart Rhythm 2006; 3:387-96. [PMID: 16567283 DOI: 10.1016/j.hrthm.2006.01.009] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.3] [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] [Received: 12/15/2005] [Accepted: 01/08/2006] [Indexed: 10/25/2022]
Abstract
BACKGROUND Numerous reports have demonstrated an association between autonomic tone and atrial fibrillation (AF). Pulmonary vein (PV) denervation during catheter ablation of AF has been shown to significantly reduce recurrence of AF. OBJECTIVES The purpose of this study was to assess the safety and efficacy of high-frequency stimulation at mapping cardiac ganglionated plexuses in patients undergoing catheter ablation of AF. METHODS Fourteen patients with a history of symptomatic AF underwent a single transseptal approach and electroanatomic mapping of the left atrium, right atrium, and coronary sinus. Using high-frequency stimulation with patients under general anesthesia (20-50 Hz, 5-15 V, pulse width 10 ms), mapping of ganglionated plexuses was performed. Radiofrequency (RF) ablation was performed during AF guided by complex fractionated atrial electrograms. Lesions were mostly delivered circumferentially in the antral area of the PVs, predominantly over and adjacent to regions of ganglionated plexuses. RESULTS There was a mean of 4 +/- 1 (range 2-6) ganglionated plexuses per patient, and a mean total of 3 +/- 1 RF applications were delivered over positive vagal sites. Although a vagal response occurred infrequently during ablation (0.9%), postablation high-frequency stimulation failed to provoke a vagal response in 30 (88%) of 34 previously positive vagal sites that underwent ablation. CONCLUSION Ganglionated plexuses can be precisely mapped using high-frequency stimulation and are located predominantly in the path of lesions delivered during ablation of AF. Objective documentation of modification of autonomic tone can be documented in the majority of patients. Future studies are required to determine the specific role of mapping and targeting of ganglionated plexuses in patients undergoing catheter ablation of AF.
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Affiliation(s)
- Robert Lemery
- Division of Cardiology, University of Ottawa Heart Institute, Ontario, Canada.
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Abstract
BACKGROUND Cardiac arrest with preserved left ventricular function may be caused by uncommon genetic conditions. Although these may be evident on the ECG, long-term monitoring or provocative testing is often necessary to unmask latent primary electrical disease. METHODS AND RESULTS Patients with unexplained cardiac arrest and no evident cardiac disease (normal left ventricular function, coronary arteries, and resting corrected QT) underwent pharmacological challenge with adrenaline and procainamide infusions to unmask subclinical primary electrical disease. Family members underwent noninvasive screening and directed provocative testing on the basis of findings in the proband. Eighteen patients (mean+/-SD age, 41+/-17 years; 11 female) with unexplained cardiac arrest were assessed. The final diagnosis was catecholaminergic ventricular tachycardia (CPVT) in 10 patients (56%), Brugada syndrome in 2 patients (11%), and unexplained (idiopathic ventricular fibrillation) in 6 patients (33%). Of 55 family members (mean+/-SD age, 27+/-17 years; 33 female), 9 additional affected family members were detected from 2 families, with a single Brugada syndrome patient and 8 CPVT patients. CONCLUSIONS Provocative testing with adrenaline and procainamide infusions is useful in unmasking the etiology of apparent unexplained cardiac arrest. This approach helps to diagnose primary electrical disease, such as CPVT and Brugada syndrome, and provides the opportunity for therapeutic intervention in identified, asymptomatic family members who harbor the same disease.
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Affiliation(s)
- Andrew D Krahn
- Division of Cardiology, University of Western Ontario, London, Canada.
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30
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Lemery R, Hendry M, Birnie D, Tang AS, Green M, Gollob M, Lau EW. Epicardial and endocardial triatrial electroanatomic mapping: A comprehensive human study of atrial activation and voltage. Heart Rhythm 2005. [DOI: 10.1016/j.hrthm.2005.02.1001] [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: 11/28/2022]
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31
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Davis DR, Krahn AD, Tang ASL, Lemery R, Green MS, Gollob M, Yee R, Skanes AC, Klein GJ, Birnie DH. Long-term outcome of cardiac resynchronization therapy in patients with severe congestive heart failure. Can J Cardiol 2005; 21:413-7. [PMID: 15861258] [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: 05/02/2023] Open
Abstract
BACKGROUND Cardiac resynchronization therapy (CRT) has recently been shown to be an effective short-term therapy for patients with drug-refractory heart failure and intraventricular conduction delay. Little is known about the long-term effects of this therapy. OBJECTIVES To determine the long-term outcome of all consecutive patients who underwent CRT at two Canadian centres, and to determine what baseline variables predict a response to CRT. RESULTS AND CONCLUSIONS The present study comprised a total of 85 patients (mean age 66+/-9 years; 88% male) with New York Heart Association class II (4%), class III (84%) or class IV (12%) heart failure. All patients fulfilled the standard CRT indications with a QRS duration of 168+/-22 ms and a nuclear gated ejection fraction (EF) of 21+/-6%. Eighteen of the 85 patients were implanted with a combination automatic implantable cardioverter-defibrillator and CRT device. Within a mean clinical follow-up of 3.0+/-1.0 years, 26 of the 85 patients died, and eight patients underwent cardiac transplantation, with four transplant-related deaths (mean survival 3.53+/-0.26 years). Ten patients died of sudden cardiac death, eight patients died of progressive heart failure and eight patients died of noncardiac causes. None of the baseline factors (age, sex, EF, etiology, New York Heart Association class, QRS duration or implantable cardioverter-defibrillator) or indexes of CRT (change in EF or QRS duration) were predictive of a poor outcome. There was a clear trend for patients with a greater left ventricular EF gain to have a better outcome (P=0.1). The present observational data represent one of the longest follow-up databases of patients undergoing CRT. The significant morbidity and mortality found after CRT highlight the severity of the underlying cardiac pathology and concurrent illnesses.
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Affiliation(s)
- Darryl R Davis
- Division of Cardiology, University of Ottawa Heart Institute, University of Ottawa, Ottawa, Ontario, Canada
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Paredes A, Hood WR, Seymour H, Gollob M. Loss of control in alcoholism. An investigation of the hypothesis, with experimental findings. Q J Stud Alcohol 1973; 34:1146-61. [PMID: 4767543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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