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Kallas D, Ghadiry-Tavi R, Roston TM, Franciosi S, Fischbach PS, Knight LM, Kannankeril PJ, Krahn AD, Kwok SY, LaPage MJ, Tisma-Dupanovic S, Atallah J, Kean AC, Etheridge SP, Hill AC, Law IH, Balaji S, Johnsrude CL, Backhoff D, Dhillon SS, Perry JC, Kubuš P, Kovach JR, Fournier A, Kamp AN, Kron J, Lau YR, Brugada GS, Hamilton RM, Sanatani S. B-PO05-167 ATRIAL TACHYARRHYTHMIAS IN CATECHOLAMINERGIC POLYMORPHIC VENTRICULAR TACHYCARDIA: A REPORT FROM THE INTERNATIONAL PEDIATRIC CPVT REGISTRY. Heart Rhythm 2021. [DOI: 10.1016/j.hrthm.2021.06.1086] [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: 11/26/2022]
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Lamba A, Roston TM, Franciosi S, Kallas D, Fischbach PS, Knight LM, Atallah J, Hill AC, Kannankeril PJ, Kwok SY, Backhoff D, LaPage MJ, Law IH, Balaji S, Dhillon SS, Krahn AD, Tisma-Dupanovic S, Etheridge SP, Johnsrude CL, Kamp AN, Kovach JR, Kubus P, Perry JC, Fournier A, Kean AC, Lau YR, Sanatani S. B-PO03-182 PRIMARY PREVENTION IMPLANTABLE CARDIOVERTER-DEFIBRILLATORS IN CHILDREN WITH CATECHOLAMINERGIC POLYMORPHIC VENTRICULAR TACHYCARDIA: A PROSPECTIVE STUDY OF THE INTERNATIONAL PEDIATRIC CPVT REGISTRY. Heart Rhythm 2021. [DOI: 10.1016/j.hrthm.2021.06.655] [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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Tan CH, Lau YR, Kay GN. A Wide QRS Tachycardia in a 17-Year-Old. Circulation 2020; 142:2475-2478. [PMID: 33347324 DOI: 10.1161/circulationaha.120.051784] [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: 11/16/2022]
Affiliation(s)
- Christian H Tan
- Department of Pediatric Cardiology, University of Alabama at Birmingham
| | - Yung R Lau
- Department of Pediatric Cardiology, University of Alabama at Birmingham
| | - G Neal Kay
- Department of Pediatric Cardiology, University of Alabama at Birmingham
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Yamada T, Lau YR. Successful slow pathway ablation in a patient with an interrupted inferior vena cava and persistent left superior vena cava. Europace 2019; 21:1012. [PMID: 30624723 DOI: 10.1093/europace/euy312] [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] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Takumi Yamada
- Division of Cardiovascular Disease, Department of Pediatric Cardiology, University of Alabama at Birmingham, FOT 930A, 510 20th Street South, Birmingham, AL, USA
| | - Yung R Lau
- Division of Cardiovascular Disease, Department of Pediatric Cardiology, University of Alabama at Birmingham, FOT 930A, 510 20th Street South, Birmingham, AL, USA
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Roston TM, Yuchi Z, Kannankeril PJ, Hathaway J, Vinocur JM, Etheridge SP, Potts JE, Maginot KR, Salerno JC, Cohen MI, Hamilton RM, Pflaumer A, Mohammed S, Kimlicka L, Kanter RJ, LaPage MJ, Collins KK, Gebauer RA, Temple JD, Batra AS, Erickson C, Miszczak-Knecht M, Kubuš P, Bar-Cohen Y, Kantoch M, Thomas VC, Hessling G, Anderson C, Young ML, Choi SHJ, Cabrera Ortega M, Lau YR, Johnsrude CL, Fournier A, Van Petegem F, Sanatani S. The clinical and genetic spectrum of catecholaminergic polymorphic ventricular tachycardia: findings from an international multicentre registry. Europace 2018; 20:541-547. [PMID: 28158428 DOI: 10.1093/europace/euw389] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 11/03/2016] [Indexed: 11/12/2022] Open
Abstract
Aims Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an ion channelopathy characterized by ventricular arrhythmia during exertion or stress. Mutations in RYR2-coded Ryanodine Receptor-2 (RyR2) and CASQ2-coded Calsequestrin-2 (CASQ2) genes underlie CPVT1 and CPVT2, respectively. However, prognostic markers are scarce. We sought to better characterize the phenotypic and genotypic spectrum of CPVT, and utilize molecular modelling to help account for clinical phenotypes. Methods and results This is a Pediatric and Congenital Electrophysiology Society multicentre, retrospective cohort study of CPVT patients diagnosed at <19 years of age and their first-degree relatives. Genetic testing was undertaken in 194 of 236 subjects (82%) during 3.5 (1.4-5.3) years of follow-up. The majority (60%) had RyR2-associated CPVT1. Variant locations were predicted based on a 3D structural model of RyR2. Specific residues appear to have key structural importance, supported by an association between cardiac arrest and mutations in the intersubunit interface of the N-terminus, and the S4-S5 linker and helices S5 and S6 of the RyR2 C-terminus. In approximately one quarter of symptomatic patients, cardiac events were precipitated by only normal wakeful activities. Conclusion This large, multicentre study identifies contemporary challenges related to the diagnosis and prognostication of CPVT patients. Structural modelling of RyR2 can improve our understanding severe CPVT phenotypes. Wakeful rest, rather than exertion, often precipitated life-threatening cardiac events.
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Affiliation(s)
- Thomas M Roston
- Departments of Pediatrics/Medicine/Biochemistry & Molecular Biology, University of British Columbia, 4480 Oak Street, Room 1F3, Vancouver, BC, V6H 3V4, Canada
| | - Zhiguang Yuchi
- Departments of Pediatrics/Medicine/Biochemistry & Molecular Biology, University of British Columbia, 4480 Oak Street, Room 1F3, Vancouver, BC, V6H 3V4, Canada
| | - Prince J Kannankeril
- Department of Pediatrics and the Vanderbilt Center for Arrhythmia Research and Therapeutics (VanCART) Vanderbilt University Medical Center and the Monroe Carell Jr. Children's Hospital at Vanderbilt, 2200 Children's Way, Suite 5230, Nashville, TN 37232-9119, USA
| | - Julie Hathaway
- BC Inherited Arrhythmia Program, 211-1033 Davie St, Vancouver, BC V6E 1M7, Canada
| | - Jeffrey M Vinocur
- Department of Pediatrics, University of Rochester, 601 Elmwood Ave, Box 631, Rochester, NY 14642, USA
| | - Susan P Etheridge
- Department of Pediatrics, University of Utah, 81 N Mario Capecchi Drive Salt Lake City, UT 84113, USA
| | - James E Potts
- Departments of Pediatrics/Medicine/Biochemistry & Molecular Biology, University of British Columbia, 4480 Oak Street, Room 1F3, Vancouver, BC, V6H 3V4, Canada
| | - Kathleen R Maginot
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, 1675 Highland Ave, Madison, WI 53792, USA
| | - Jack C Salerno
- Department of Pediatrics, University of Washington, 4800 Sand Point Way NE, Seattle, WA 98105, USA
| | - Mitchell I Cohen
- Division of Cardiology Phoenix Children's Hospital, 1919 E. Thomas Road, 2nd Floor, Heart Center, Phoenix, AZ 85016, USA
| | - Robert M Hamilton
- Department of Pediatrics, University of Toronto, Hospital for Sick Children, 555 University Avenue Toronto, Ontario M5G 1X8, Canada
| | - Andreas Pflaumer
- Royal Children's Hospital MCRI and University of Melbourne, 50 Flemington Road Parkville, Melbourne 3052, Australia
| | - Saira Mohammed
- Departments of Pediatrics/Medicine/Biochemistry & Molecular Biology, University of British Columbia, 4480 Oak Street, Room 1F3, Vancouver, BC, V6H 3V4, Canada
| | - Lynn Kimlicka
- Departments of Pediatrics/Medicine/Biochemistry & Molecular Biology, University of British Columbia, 4480 Oak Street, Room 1F3, Vancouver, BC, V6H 3V4, Canada
| | - Ronald J Kanter
- Nicklaus Children's Hospital, 3100 SW 62 Ave, Cardiology ACB - 2nd Floor Miami, FL 33155, USA
| | - Martin J LaPage
- Department of Pediatrics, University of Michigan, 1500 E Medical Center Drive, #6303, Ann Arbor, MI 48109, USA
| | - Kathryn K Collins
- Department of Pediatrics, University of Colorado, 13123 East 16th Avenue, Aurora, CO 80045, USA
| | - Roman A Gebauer
- Department of Pediatric Cardiology, Heart Center, University of Leipzig, Strümpellstrasse 39, Leipzig, Germany
| | - Joel D Temple
- Department of Pediatrics, A. I. DuPont Hospital For Children, 1600 Rockland Rd, Wilmington, DE 19803, USA
| | - Anjan S Batra
- Department of Pediatrics, University of California at Irvine Medical Center, 1140 W. La Veta Ave., Suite 750, Orange, CA 92868, USA
| | - Christopher Erickson
- Division of Cardiology, UNMC/CUMC/Children's Hospital and Medical Center, 8200 Dodge Street, Omaha, NE 68114, USA
| | - Maria Miszczak-Knecht
- Department of Cardiology, Children's Memorial Health Institute, Dzieci Polskich 20, 04 -730 Warsaw, Poland
| | - Peter Kubuš
- Children's Heart Centre, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Vúvalu 84, 15006, Prague, Czech Republic
| | - Yaniv Bar-Cohen
- Department of Pediatrics, Children's Hospital Los Angeles, 4650 Sunset Blvd #34, Los Angeles, CA 90027, USA
| | - Michal Kantoch
- Stollery Children's Hospital, University of Alberta, Clinical Sciences Building, 8440 112 St NW, Edmonton, AB T6G 2B7, Canada
| | - Vincent C Thomas
- Division of Cardiology, UNMC/CUMC/Children's Hospital and Medical Center, 8200 Dodge Street, Omaha, NE 68114, USA
| | - Gabriele Hessling
- Department of Electrophysiology, German Heart Center Munich, Technical University, Lazarettstr. 3680636 Munich, Germany
| | - Chris Anderson
- Providence Sacred Heart Children's Hospital, 101 W. 8th Ave. Suite 4300E, Spokane, WA 99204, USA
| | - Ming-Lon Young
- Department of Pediatrics, Joe DiMaggio Children's Hospital, 1150 North 35th Avenue Suite 575, Hollywood, FL 33021, USA
| | - Sally H J Choi
- Departments of Pediatrics/Medicine/Biochemistry & Molecular Biology, University of British Columbia, 4480 Oak Street, Room 1F3, Vancouver, BC, V6H 3V4, Canada
| | - Michel Cabrera Ortega
- Department of Arrhythmia and Cardiac Pacing, Cardiocentro Pediatrico William Soler, 100 y perla, Boyeros. 10800, Havana, Cuba
| | - Yung R Lau
- Division of Pediatric Cardiology, University of Alabama at Birmingham, 1700 6th Ave S, Birmingham, AL 35233, USA
| | - Christopher L Johnsrude
- Department of Pediatrics, University of Louisville, 601 S Floyd St #602, Louisville, KY 40208, USA
| | - Anne Fournier
- Département de Pédiatrie, CHU Ste Justine, 3175, chemin Côte Sainte-Catherine, Montréal, QC H3T 1C5 Canada
| | - Filip Van Petegem
- Departments of Pediatrics/Medicine/Biochemistry & Molecular Biology, University of British Columbia, 4480 Oak Street, Room 1F3, Vancouver, BC, V6H 3V4, Canada
| | - Shubhayan Sanatani
- Departments of Pediatrics/Medicine/Biochemistry & Molecular Biology, University of British Columbia, 4480 Oak Street, Room 1F3, Vancouver, BC, V6H 3V4, Canada
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Roston TM, Haji-Ghassemi O, LaPage MJ, Batra AS, Bar-Cohen Y, Anderson C, Lau YR, Maginot K, Gebauer RA, Etheridge SP, Potts JE, Van Petegem F, Sanatani S. Catecholaminergic polymorphic ventricular tachycardia patients with multiple genetic variants in the PACES CPVT Registry. PLoS One 2018; 13:e0205925. [PMID: 30403697 PMCID: PMC6221297 DOI: 10.1371/journal.pone.0205925] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [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: 07/20/2018] [Accepted: 10/03/2018] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Catecholaminergic polymorphic ventricular tachycardia (CPVT) is often a life-threatening arrhythmia disorder with variable penetrance and expressivity. Little is known about the incidence or outcomes of CPVT patients with ≥2 variants. METHODS The phenotypes, genotypes and outcomes of patients in the Pediatric and Congenital Electrophysiology Society CPVT Registry with ≥2 variants in genes linked to CPVT were ascertained. The American College of Medical Genetics & Genomics (ACMG) criteria and structural mapping were used to predict the pathogenicity of variants (3D model of pig RyR2 in open-state). RESULTS Among 237 CPVT subjects, 193 (81%) had genetic testing. Fifteen patients (8%) with a median age of 9 years (IQR 5-12) had ≥2 variants. Sudden cardiac arrest occurred in 11 children (73%), although none died during a median follow-up of 4.3 years (IQR 2.5-6.1). Thirteen patients (80%) had at least two RYR2 variants, while the remaining two patients had RYR2 variants plus variants in other CPVT-linked genes. Among all variants identified, re-classification of the commercial laboratory interpretation using ACMG criteria led to the upgrade from variant of unknown significance (VUS) to pathogenic/likely pathogenic (P/LP) for 5 variants, and downgrade from P/LP to VUS for 6 variants. For RYR2 variants, 3D mapping using the RyR2 model suggested that 2 VUS by ACMG criteria were P/LP, while 2 variants were downgraded to likely benign. CONCLUSIONS This severely affected cohort demonstrates that a minority of CPVT cases are related to ≥2 variants, which may have implications on family-based genetic counselling. While multi-variant CPVT patients were at high-risk for sudden cardiac arrest, there are insufficient data to conclude that this genetic phenomenon has prognostic implications at present. Further research is needed to determine the significance and generalizability of this observation. This study also shows that a rigorous approach to variant re-classification using the ACMG criteria and 3D mapping is important in reaching an accurate diagnosis, especially in the multi-variant population.
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Affiliation(s)
- Thomas M. Roston
- Departments of Medicine, Pediatrics, and Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC, Canada
- Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Omid Haji-Ghassemi
- Departments of Medicine, Pediatrics, and Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Martin J. LaPage
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, United States of America
| | - Anjan S. Batra
- Department of Pediatrics, University of California at Irvine Medical Center, Irvine, CA, United States of America
| | - Yaniv Bar-Cohen
- Department of Pediatrics, Children’s Hospital Los Angeles, Los Angeles, CA, United States of America
| | - Chris Anderson
- Providence Sacred Heart Children’s Hospital, Spokane, WA, United States of America
| | - Yung R. Lau
- Division of Pediatric Cardiology, University of Alabama at Birmingham, Birmingham, AB, United States of America
| | - Kathleen Maginot
- Department of Pediatrics, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States of America
| | - Roman A. Gebauer
- Department of Pediatric Cardiology, University of Leipzig, Leipzig, Germany
| | - Susan P. Etheridge
- Department of Pediatrics, University of Utah, and Primary Children’s Hospital, Salt Lake City, UT, United States of America
| | - James E. Potts
- Departments of Medicine, Pediatrics, and Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Filip Van Petegem
- Departments of Medicine, Pediatrics, and Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Shubhayan Sanatani
- Departments of Medicine, Pediatrics, and Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC, Canada
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Yamada T, Lau YR. Successful catheter ablation of a focal atrial tachycardia originating from the coronary sinus ostium in a patient with a history of Fontan conversion and dextrocardia. Europace 2018; 20:1351. [PMID: 29688296 DOI: 10.1093/europace/euy061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Takumi Yamada
- Division of Cardiovascular Disease, Department of Pediatric Cardiology, University of Alabama at Birmingham, FOT 930A, 510 20th Street South, Birmingham, AL, USA
| | - Yung R Lau
- Division of Cardiovascular Disease, Department of Pediatric Cardiology, University of Alabama at Birmingham, FOT 930A, 510 20th Street South, Birmingham, AL, USA
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Lau YR, Kay GN. Supraventricular Tachycardia With Something Missing. Circulation 2018; 137:2076-2079. [PMID: 29735593 DOI: 10.1161/circulationaha.118.034773] [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: 11/16/2022]
Affiliation(s)
| | - G Neal Kay
- Medicine (G.N.K.), University of Alabama at Birmingham.
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Yamada T, Lau YR, Kay GN. Atrioventricular Nodal Reentrant Tachycardia With a Displaced His-Bundle in an Atrioventricular Canal Defect. J Cardiovasc Electrophysiol 2016; 28:120-121. [PMID: 27616545 DOI: 10.1111/jce.13099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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: 08/20/2016] [Revised: 08/30/2016] [Accepted: 09/07/2016] [Indexed: 11/26/2022]
Affiliation(s)
- Takumi Yamada
- Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Yung R Lau
- Department of Pediatric Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - G Neal Kay
- Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Boczek NJ, Gomez-Hurtado N, Ye D, Calvert ML, Tester DJ, Kryshtal D, Hwang HS, Johnson CN, Chazin WJ, Loporcaro CG, Shah M, Papez AL, Lau YR, Kanter R, Knollmann BC, Ackerman MJ. Spectrum and Prevalence of CALM1-, CALM2-, and CALM3-Encoded Calmodulin Variants in Long QT Syndrome and Functional Characterization of a Novel Long QT Syndrome-Associated Calmodulin Missense Variant, E141G. ACTA ACUST UNITED AC 2016; 9:136-146. [PMID: 26969752 DOI: 10.1161/circgenetics.115.001323] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 03/04/2016] [Indexed: 12/22/2022]
Abstract
BACKGROUND Calmodulin (CaM) is encoded by 3 genes, CALM1, CALM2, and CALM3, all of which harbor pathogenic variants linked to long QT syndrome (LQTS) with early and severe expressivity. These LQTS-causative variants reduce CaM affinity to Ca(2+) and alter the properties of the cardiac L-type calcium channel (CaV1.2). CaM also modulates NaV1.5 and the ryanodine receptor, RyR2. All these interactions may play a role in disease pathogenesis. Here, we determine the spectrum and prevalence of pathogenic CaM variants in a cohort of genetically elusive LQTS, and functionally characterize the novel variants. METHODS AND RESULTS Thirty-eight genetically elusive LQTS cases underwent whole-exome sequencing to identify CaM variants. Nonsynonymous CaM variants were over-represented significantly in this heretofore LQTS cohort (13.2%) compared with exome aggregation consortium (0.04%; P<0.0001). When the clinical sequelae of these 5 CaM-positive cases were compared with the 33 CaM-negative cases, CaM-positive cases had a more severe phenotype with an average age of onset of 10 months, an average corrected QT interval of 676 ms, and a high prevalence of cardiac arrest. Functional characterization of 1 novel variant, E141G-CaM, revealed an 11-fold reduction in Ca(2+)-binding affinity and a functionally dominant loss of inactivation in CaV1.2, mild accentuation in NaV1.5 late current, but no effect on intracellular RyR2-mediated calcium release. CONCLUSIONS Overall, 13% of our genetically elusive LQTS cohort harbored nonsynonymous variants in CaM. Genetic testing of CALM1-3 should be pursued for individuals with LQTS, especially those with early childhood cardiac arrest, extreme QT prolongation, and a negative family history.
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Affiliation(s)
- Nicole J Boczek
- Department Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN
| | | | - Dan Ye
- Department Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN
| | - Melissa L Calvert
- Department Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN
| | - David J Tester
- Department Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN
| | - Dmytro Kryshtal
- Department of Medicine, Vanderbilt University, Nashville, TN
| | - Hyun Seok Hwang
- Department of Medicine, Vanderbilt University, Nashville, TN
| | - Christopher N Johnson
- Departments of Biochemistry & Chemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN
| | - Walter J Chazin
- Departments of Biochemistry & Chemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN
| | - Christina G Loporcaro
- Department Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN.,Mayo Medical School, Mayo Clinic, Rochester, MN
| | - Maully Shah
- Children's Hospital of Philadelphia, Philadelphia, PA
| | - Andrew L Papez
- Department of Pediatric Cardiology, Phoenix Children's Hospital, Phoenix, AZ
| | - Yung R Lau
- Department of Pediatrics, Division of Pediatric Cardiology, University of Alabama at Birmingham, Birmingham, AL
| | - Ronald Kanter
- Division of Cardiology, Nicklaus Children's Hospital, Miami, FL
| | | | - Michael J Ackerman
- Department Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN.,Department of Medicine, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.,Department of Pediatrics, Division of Pediatric Cardiology, Mayo Clinic, Rochester, MN
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Roston TM, Vinocur JM, Maginot KR, Mohammed S, Salerno JC, Etheridge SP, Cohen M, Hamilton RM, Pflaumer A, Kanter RJ, Potts JE, LaPage MJ, Collins KK, Gebauer RA, Temple JD, Batra AS, Erickson C, Miszczak-Knecht M, Kubuš P, Bar-Cohen Y, Kantoch M, Thomas VC, Hessling G, Anderson C, Young ML, Ortega MC, Lau YR, Johnsrude CL, Fournier A, Kannankeril PJ, Sanatani S. Catecholaminergic polymorphic ventricular tachycardia in children: analysis of therapeutic strategies and outcomes from an international multicenter registry. Circ Arrhythm Electrophysiol 2015; 8:633-42. [PMID: 25713214 PMCID: PMC4472494 DOI: 10.1161/circep.114.002217] [Citation(s) in RCA: 165] [Impact Index Per Article: 18.3] [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] [Received: 05/06/2014] [Accepted: 02/11/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Catecholaminergic polymorphic ventricular tachycardia is an uncommon, potentially lethal, ion channelopathy. Standard therapies have high failure rates and little is known about treatment in children. Newer options such as flecainide and left cardiac sympathetic denervation are not well validated. We sought to define treatment outcomes in children with catecholaminergic polymorphic ventricular tachycardia. METHODS AND RESULTS This is a Pediatric and Congenital Electrophysiology Society multicenter, retrospective cohort study of catecholaminergic polymorphic ventricular tachycardia patients diagnosed before 19 years of age. The cohort included 226 patients, including 170 probands and 56 relatives. Symptomatic presentation was reported in 176 (78%). Symptom onset occurred at 10.8 (interquartile range, 6.8-13.2) years with a delay to diagnosis of 0.5 (0-2.6) years. Syncope (P<0.001), cardiac arrest (P<0.001), and treatment failure (P=0.008) occurred more often in probands. β-Blockers were prescribed in 205 of 211 patients (97%) on medication, and 25% experienced at least 1 treatment failure event. Implantable cardioverter defibrillators were placed in 121 (54%) and was associated with electrical storm in 22 (18%). Flecainide was used in 24% and left cardiac sympathetic denervation in 8%. Six deaths (3%) occurred during a cumulative follow-up of 788 patient-years. CONCLUSIONS This study demonstrates a malignant phenotype and lengthy delay to diagnosis in catecholaminergic polymorphic ventricular tachycardia. Probands were typically severely affected. β-Blockers were almost universally initiated; however, treatment failure, noncompliance and subtherapeutic dosing were often reported. Implantable cardioverter defibrillators were common despite numerous device-related complications. Treatment failure was rare in the quarter of patients on flecainide. Left cardiac sympathetic denervation was not uncommon although the indication was variable.
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MESH Headings
- Adolescent
- Age Factors
- Anti-Arrhythmia Agents/adverse effects
- Anti-Arrhythmia Agents/therapeutic use
- Child
- Death, Sudden, Cardiac/etiology
- Death, Sudden, Cardiac/prevention & control
- Defibrillators, Implantable
- Electric Countershock/adverse effects
- Electric Countershock/instrumentation
- Electric Countershock/mortality
- Female
- Humans
- Male
- Patient Selection
- Phenotype
- Registries
- Retrospective Studies
- Risk Factors
- Severity of Illness Index
- Sympathectomy/adverse effects
- Sympathectomy/mortality
- Tachycardia, Ventricular/complications
- Tachycardia, Ventricular/diagnosis
- Tachycardia, Ventricular/mortality
- Tachycardia, Ventricular/physiopathology
- Tachycardia, Ventricular/therapy
- Time Factors
- Treatment Outcome
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Affiliation(s)
- Thomas M. Roston
- Department of Pediatrics, Divisions of Cardiology, University of British Columbia, Vancouver, BC, Canada
| | | | | | - Saira Mohammed
- Department of Pediatrics, Divisions of Cardiology, University of British Columbia, Vancouver, BC, Canada
| | - Jack C. Salerno
- Department of Pediatrics, University of Washington, Seattle, WA
| | | | | | | | - Andreas Pflaumer
- Royal Children’s Hospital MCRI & University of Melbourne, Australia
| | | | - James E. Potts
- Department of Pediatrics, Divisions of Cardiology, University of British Columbia, Vancouver, BC, Canada
| | | | | | | | | | - Anjan S. Batra
- University of California at Irvine Medical Center, Orange, CA
| | | | | | - Peter Kubuš
- Children’s Heart Center, Prague, Czech Republic
| | | | - Michal Kantoch
- Stollery Children’s Hospital, University of Alberta, Edmonton, AB, Canada
| | | | | | - Chris Anderson
- Providence Sacred Heart Children’s Hospital, Spokane, WA
| | | | | | - Yung R. Lau
- University of Alabama at Birmingham, Birmingham, AL
| | | | | | | | - Shubhayan Sanatani
- Department of Pediatrics, Divisions of Cardiology, University of British Columbia, Vancouver, BC, Canada
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Yamada T, Lau YR, Kay GN. Successful cavotricuspid isthmus ablation in a patient with an interrupted inferior vena cava and persistent left superior vena cava. J Cardiovasc Electrophysiol 2014; 26:450-451. [PMID: 25425487 DOI: 10.1111/jce.12588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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] [Indexed: 11/30/2022]
Affiliation(s)
- Takumi Yamada
- Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Yung R Lau
- Department of Pediatric Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - G Neal Kay
- Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Yamada T, Lau YR, Litovsky SH, Thomas McElderry H, Doppalapudi H, Osorio J, Plumb VJ, Neal Kay G. Prevalence and clinical, electrocardiographic, and electrophysiologic characteristics of ventricular arrhythmias originating from the noncoronary sinus of Valsalva. Heart Rhythm 2013; 10:1605-12. [DOI: 10.1016/j.hrthm.2013.08.017] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Indexed: 11/26/2022]
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Johnson JN, Harris KM, Moir C, Lau YR, Ackerman MJ. Left cardiac sympathetic denervation in a pediatric patient with hypertrophic cardiomyopathy and recurrent ventricular fibrillation. Heart Rhythm 2011; 8:1591-4. [PMID: 21459160 DOI: 10.1016/j.hrthm.2011.03.056] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Accepted: 03/25/2011] [Indexed: 10/18/2022]
Affiliation(s)
- Jonathan N Johnson
- Department of Pediatrics/Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minnesota 55905, USA
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Yamada T, Lau YR, McElderry HT, Kay GN. Prolongation of local ventriculoatrial conduction during left lateral accessory pathway ablation: what is the mechanism? Heart Rhythm 2010; 8:942-3. [PMID: 20816870 DOI: 10.1016/j.hrthm.2010.08.021] [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] [Received: 08/23/2010] [Indexed: 11/25/2022]
Affiliation(s)
- Takumi Yamada
- Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, Alabama, USA. -.ne.jp
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Pearce FB, Kirklin JK, Holman WL, Barrett CS, Romp RL, Lau YR. Successful cardiac transplant after Berlin Heart bridge in a single ventricle heart: Use of aortopulmonary shunt as a supplementary source of pulmonary blood flow. J Thorac Cardiovasc Surg 2009; 137:e40-2. [DOI: 10.1016/j.jtcvs.2008.02.044] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Accepted: 02/07/2008] [Indexed: 11/28/2022]
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Yamada T, Lau YR, McElderry HT, Doppalapudi H, Kay GN. Adenosine can improve the intra-atrial conduction block along the mitral annulus during accessory pathway ablation. Europace 2008; 10:303-5. [PMID: 18308752 DOI: 10.1093/europace/eun036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A 10-year-old boy with a supraventricular tachycardia was referred for catheter ablation. An electrophysiologic study revealed a left lateral concealed accessory pathway (AP). A few radiofrequency (RF) applications targeting the AP resulted in an inadvertent intra-atrial conduction block at the mitral isthmus without any damage to the AP. Adenosine was then administered during left ventricular pacing. Soon after that, the conduction at the mitral isthmus recovered partially, and that change disappeared soon. Those findings suggested that the administration of adenosine may transiently recover the conduction at the mitral isthmus damaged by RF ablation.
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Affiliation(s)
- Takumi Yamada
- Division of Cardiovascular Diseases, University of Alabama at Birmingham, VH B147, 1670 University Boulevard, 1530 3rd Avenue South, Birmingham, AL 35294-0019, USA.
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Abstract
A 12-year-old boy born with double outlet right ventricle (RV) developed sustained ventricular tachycardia (VT) 6 years after the corrective surgery and underwent electrophysiologic testing and catheter ablation. Electroanatomic mapping of the right and left ventricles during the VT revealed a centrifugal activation from the outflow tract septum. Though an excellent pace map was obtained in the RV, successful ablation was achieved on the left side. These findings suggested that the VT origin might have been located in the intramural region of the ventricular outflow tract septum with a preferential breakout site in the RV outflow tract.
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Affiliation(s)
- Takumi Yamada
- Division of Cardiovascular Diseases, Cardiac Rhythm Management Laboratory, University of Alabama at Birmingham, Birmingham, AL 35294-0019, USA.
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Abstract
BACKGROUND Atrial fibrillation (AF) is uncommon in children, and its mechanisms are unknown. This study describes the electrophysiological findings in children and adolescents with AF and the outcome of catheter ablation. METHODS AND RESULTS Nine adolescents with symptomatic, lone AF who failed antiarrhythmic drug therapy were evaluated. All patients had ECG-documented AF and underwent invasive electrophysiological testing. Intracardiac mapping was performed to determine the site of spontaneous onset of AF and rapidly firing atrial foci. Only the triggering focus was targeted for ablation or isolation. The patients' mean age was 15.9+/-3.3 (range, 8 to 19 years). The most common finding was rapid, irregular atrial tachycardias in the region of the pulmonary veins (n=5), left atrium (n=2), or crista terminalis (n=3). One patient had foci in both the pulmonary veins and crista terminalis. The cycle lengths ranged from 108 to 280 ms. Catheter ablation was acutely successful in 8 patients (88.9%), whereas 1 patient with multiple left atrium foci was treated with the surgical maze operation. Over a mean of 35+/-22 months, 7 patients (77.8%) were arrhythmia free on no medications, while AF recurred in 2 patients who are controlled on antiarrhythmic medications. Two patients with tachycardia-induced cardiomyopathy had resolution of their left ventricular dysfunction after ablation. CONCLUSIONS AF in adolescents with structurally normal hearts is usually due to foci in the pulmonary veins, crista terminalis, or left atrium. These foci usually induce irregular atrial tachycardias. Catheter ablation of the foci is effective in eliminating recurrent AF.
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Affiliation(s)
- Kumaraswamy Nanthakumar
- Division of Cardiovascular Diseases, University of Alabama at Birmingham, 1670 University Blvd, B140 Volker Hall, Birmingham AL 35294-0019, USA.
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Johnson WH, Yang P, Yang T, Lau YR, Mostella BA, Wolff DJ, Roden DM, Benson DW. Clinical, genetic, and biophysical characterization of a homozygous HERG mutation causing severe neonatal long QT syndrome. Pediatr Res 2003; 53:744-8. [PMID: 12621127 DOI: 10.1203/01.pdr.0000059750.17002.b6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [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: 12/19/2022]
Abstract
Previous studies have identified mutations in five ion channel genes as a cause of long QT syndrome, a heterogeneous disorder characterized by prolongation of the QT interval, multiform ventricular tachycardia (torsades de pointes), seizures, syncope, and sudden death. However, in these studies, the average age of initial symptoms is in the third decade of life or later, and few reports have described the genetic causes of long QT syndrome presenting in the prenatal or neonatal period. We used a candidate gene approach to identify the genetic cause of long QT syndrome in an infant whose initial manifestations were detected in utero. Direct bidirectional sequencing of long QT syndrome genes identified a previously unreported HERG missense mutation (R752Q). Three asymptomatic family members were heterozygous for R752Q, and the proband, who manifested ventricular tachycardia in utero, was homozygous. R752Q was not found in 100 normal unrelated chromosomes. Paternal DNA was unavailable for testing. Transient transfection of HERG generated robust IKr, but no current was observed for the mutant HERG. The HERG mutant, R752Q, is associated with a mild phenotype, inasmuch as family members with a heterozygous mutation appear unaffected. The homozygous mutation results in absence of functional IKr, causing a profound loss of HERG channel function, creating the equivalent of a "HERG knockout" and leading to a severe phenotype.
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Affiliation(s)
- Walter H Johnson
- Department of Pediatrics, L.M. Bargeron Division of Pediatric Cardiology, University of Alabama at Birmingham, USA.
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Martin RE, Ellenbogen KA, Lau YR, Hall JA, Kay GN, Shepard RK, Nixon JV, Wood MA. Phased-array intracardiac echocardiography during pulmonary vein isolation and linear ablation for atrial fibrillation. J Cardiovasc Electrophysiol 2002; 13:873-9. [PMID: 12380925 DOI: 10.1046/j.1540-8167.2002.00873.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [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 Fluoroscopic imaging provides limited anatomic guidance for left atrial structures. The aim of this study was to determine the utility of real-time, phased-array intracardiac echocardiography during radiofrequency ablation for atrial fibrillation. METHODS AND RESULTS In 29 patients undergoing pulmonary vein isolation (n = 16) or linear (n = 13) left atrial radiofrequency ablation for atrial fibrillation, intracardiac phased-array echocardiography was used to visualize left atrial anatomy and the pulmonary veins, as well as ablation and mapping catheters during ablation procedures. In the 16 pulmonary vein isolation patients, the mean pulmonary vein ostial diameters measured by venography and intracardiac echocardiography were similar for all veins positions, except that left common pulmonary vein diameters were larger as measured by echocardiography (2.50 +/- 0.29 cm) than by venography (1.79 +/- 0.50 cm, P = 0.001). The ostial diameters measured by echocardiography and venography were not correlated, however (r = 0.23, P = 0.19). As directed by echocardiography, only 1 of 25 circular mapping catheters (4%) used in 16 patients was replaced due to inappropriate sizing of the pulmonary veins. Mean pulmonary vein Doppler flow velocities increased after ablation for left-sided veins but ostial diameters were unchanged. In the linear ablation patients, the entire extent of the linear electrode array could be visualized in only 3 of 52 of catheter positions (6%) in the 13 patients. A portion of the catheter could be seen in only 50% of all target catheter positions. CONCLUSION Phased-array intracardiac echocardiography (1) allows sizing and positioning of pulmonary vein mapping catheters, (2) provides measures of pulmonary vein ostial diameters, (3) continuously monitors pulmonary vein Doppler flow velocities, and (4) has limited use in positioning linear ablation catheters in the left atrium.
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Affiliation(s)
- Robert E Martin
- Department of Internal Medicine, Virginia Commonwealth University's Medical College of Virginia, Richmond 23219, USA
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Abstract
We report the application of emergent cardiopulmonary bypass (CPB) for three pediatric patients in the cardiac catheterization laboratory with cardiac arrest who did not respond to conventional resuscitation efforts. All three patients had return of baseline prearrest rhythms within minutes of the initiation of artificial cardiopulmonary support and the return of spontaneous circulation upon weaning CPB. Two patients had normal neurologic outcomes despite an interval of over 30 minutes from arrest to CPB. The continued judicious application and study of this technology in a small subpopulation of pediatric cardiac arrest patients is warranted.
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Affiliation(s)
- J B Cochran
- Division of Pediatric Critical Care, Children's Hospital, Medical University of South Carolina, Charleston 29425-3305, USA
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Abstract
Prolonged QRS duration on the electrocardiogram has been found to predict adverse arrhythmic events in patients late after repair of tetralogy of Fallot. Whether QRS duration can also predict inducible ventricular tachycardia (VT) at electrophysiologic study is unknown. Between 1984 and 1995 we studied 135 survivors of tetralogy of Fallot surgery whose age at surgery was 34 days to 37 years (3.7 +/- 3.9, median 2.5) and age at electrophysiologic study was 1.4 to 43 years (9.7 +/- 8.2, median 6.7). QRS duration was 80 to 240 ms (137 +/- 29) and > or = 180 ms in 9 patients. Sustained VT was induced in 22 patients (monomorphic in 17). Induced sustained monomorphic VT was related to QRS duration, right ventricular dimension, H-V interval, and presence of symptoms. QRS duration was also related to induced sustained monomorphic VT by multivariate analysis. QRS duration > or = 180 ms was 35% sensitive and 97% specific for induced sustained monomorphic VT. QRS duration was related to induced sustained monomorphic VT even when only asymptomatic patients were analyzed. A QRS duration > or = 180 ms was 100% sensitive and 96% specific for detecting clinical VT. Prolonged QRS duration on the electrocardiogram is associated with induced sustained monomorphic VT on electrophysiologic study. The finding of prolonged QRS duration should suggest the need for further testing to determine the risk of adverse arrhythmic events in patients after repair of tetralogy of Fallot, even if they are asymptomatic.
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Affiliation(s)
- S Balaji
- Division of Pediatric Cardiology, Medical University of South Carolina, Charleston 29425, USA
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Abstract
OBJECTIVE To study the effect of sympathetic stimulation and increase in heart rate on the QT and QTc intervals. DESIGN Prospective non-randomised study of eight consecutive patients. SETTING Electrophysiology laboratory at a tertiary centre. PATIENTS Eight patients aged 10-20 years (median 12.5) undergoing repeat electrophysiological study after previously successful catheter ablation (n = 6) or presumed supraventricular tachycardia (n = 2) with negative studies. INTERVENTIONS Electrocardiograms were obtained (a) at baseline, (b) during atrial pacing at 450 ms cycle length, (c) during isoprenaline infusion at 0.025 microgram/kg/min, (d) adding atrial pacing (450 ms cycle length) to isoprenaline at 0.025 microgram/kg/min, and (e) isoprenaline at 0.05 microgram/kg/min. MAIN OUTCOME MEASURES QT and QTc intervals at each of the above mentioned stages. RESULTS The QT interval was reduced from a mean value of 350 ms to around 315-325 ms by each of the above manoeuvres. Correspondingly, the QTc increased from a mean of 407 ms to around 445-470 ms. Pacing was as effective as isoprenaline in shortening the QT interval and prolonging the QTc intervals. CONCLUSIONS Heart rate directly influences QT and QTc intervals in children and adolescents. The QT is shortened, but QTc is prolonged. Hence, reliance on the QTc alone could lead to mistaken diagnosis of long QT syndrome.
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Affiliation(s)
- S Balaji
- South Carolina Children's Heart Center, Medical University of South Carolina, Charleston 29425, USA
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Colvin EV, Lau YR, Samdarshi TE. Vegetation biopsy using transesophageal echocardiography guidance: a technique to aid in diagnosis of culture-negative endocarditis. Cathet Cardiovasc Diagn 1996; 37:215-7. [PMID: 8808086 DOI: 10.1002/(sici)1097-0304(199602)37:2<215::aid-ccd25>3.0.co;2-h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A method of obtaining a vegetation sample in a culture-negative endocarditis is described. A combination of fluoroscopy and transesophageal echocardiography was utilized to obtain the sample. The results positively influenced the diagnosis and treatment in this 16-yr-old male with complex congenital heart disease.
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Affiliation(s)
- E V Colvin
- Department of Pediatrics, University of Alabama at Birmingham 35294-0007, USA
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Lau YR, Case CL, Gillette PC, Shuler CO, Fyfe DA, Knick BJ, Buckles DS. Frequency of atrioventricular valve dysfunction after radiofrequency catheter ablation via the atrial approach in children. Am J Cardiol 1994; 74:617-8. [PMID: 8074051 DOI: 10.1016/0002-9149(94)90757-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [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: 01/28/2023]
Affiliation(s)
- Y R Lau
- Division of Pediatric Cardiology, South Carolina Children's Heart Center, Medical University of South Carolina, Charleston 29425
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Abstract
This study was undertaken to examine the actuarial survival of endocardial pacing leads in a pediatric population. We prospectively followed 148 children and young adults age 4 months to 38 years. Of these, 58 had normal cardiac anatomy and 90 had surgically corrected congenital heart disease. A total of 213 leads were inserted in these patients. Actuarial analysis showed that at 5 years 76.0% of the pacemaker leads were still in use. The reasons for abandonment included death (10), exit block (8), lead fracture (8), adapter malfunction (7), and other including infection, lead migration, and pacemaker malfunction (12). Excluding deaths, an actuarial survival curve was constructed. Stepwise discriminant analysis and independent measures of association showed a significant difference in lead abandonment when the leads placed in the atrium were compared to those placed in the ventricle (30 vs 5; P < 0.0005). Lead insulating material, cardiac anatomy, and/or indication for pacemaker placement had no statistically significant impact on lead survival.
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Affiliation(s)
- Y R Lau
- Medical University of South Carolina, South Carolina Children's Heart Center, Charleston 29425
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Lau YR, Gillette PC, Case CL, Stammers A, Kratz J, Davis B. Successful treatment of medically refractory ventricular fibrillation with emergency cardiopulmonary bypass in an adolescent with corrected complex congenital heart disease. Am J Cardiol 1992; 70:699-700. [PMID: 1510025 DOI: 10.1016/0002-9149(92)90218-n] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 12/27/2022]
Affiliation(s)
- Y R Lau
- Division of Pediatric Cardiology, Charleston, South Carolina 29425
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Affiliation(s)
- Y R Lau
- Medical University of South Carolina, Children's Heart Center, Charleston 29425
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Crawford JM, Lau YR, Bull B. Calibration of hematology analyzers. Role of the microhematocrit. Arch Pathol Lab Med 1987; 111:324-7. [PMID: 3827540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Discrepancies between the hematocrit values measured by automated methods and those measured by centrifugation have discouraged the use of the centrifuged microhematocrit to calibrate automated hematology analyzers. The discrepancy appears to be due to changes in the internal viscosity of red blood cells and can be eliminated in the most popular line of automated whole blood analyzers (Coulter Counters) by use of a simple correction table. Fresh blood obtained from volunteers was separated by centrifugation into fractions of increasing mean corpuscular hemoglobin concentration. A correction table for hematocrit values obtained by automated equipment was derived from the linear relationship between the discrepancy in hematocrit values and the manually obtained values for mean corpuscular hemoglobin concentration. With the use of the correction table, an average of three randomly selected fresh blood samples is sufficient to transfer a centrifugally determined hematocrit value to a multichannel analyzer with a coefficient of variation of 1.5%. Thus, this straightforward approach permits the microhematocrit to function as a practical calibration standard.
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