9,320 results match your criteria Long QT Syndrome


The citrus flavanone hesperetin preferentially inhibits slow-inactivating currents of an LQT3 syndrome Na channel mutation.

Br J Pharmacol 2019 Jan 16. Epub 2019 Jan 16.

Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, Leuven, Belgium.

Background And Purpose: The citrus flavanone hesperetin (HSP) has been proposed for the treatment of several human pathologies, but its cardiovascular actions remain largely unexplored. Here we evaluated HSP effects on cardiac electrical and contractile activities, on aortic contraction, on the wild type voltage-gated Na channel Na 1.5 and on a channel mutant (R1623Q) associated with lethal ventricular arrhythmias in the Long QT syndrome subtype 3 (LQT3). Read More

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http://dx.doi.org/10.1111/bph.14577DOI Listing
January 2019

The necessity of implantable cardioverter defibrillators in patients with Kearns-Sayre syndrome - systematic review of the articles.

Int J Cardiol 2018 Dec 27. Epub 2018 Dec 27.

Department of Pathophysiology, Oita University, 1397-1, Yamane, Hidaka, Saitama 350-1298, Japan.

The most common cardiac feature of Kearns-Sayre syndrome (KSS) is atrioventricular block (AVB), and pacemaker implantations (PMIs) are recommended for KSS patients with advanced AVB. However, some KSS patients develop fatal arrhythmias such as polymorphic ventricular tachycardia (PMVT) and ventricular fibrillation (VF) and die suddenly even after PMIs. We report a patient with KSS who developed PMVT, VF, and QT prolongation, and was treated with mexiletine and successfully managed with an implantable cardioverter defibrillator (ICD). Read More

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http://dx.doi.org/10.1016/j.ijcard.2018.12.064DOI Listing
December 2018

Transcription alterations of KCNQ1 associated with imprinted methylation defects in the Beckwith-Wiedemann locus.

Genet Med 2019 Jan 12. Epub 2019 Jan 12.

Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università della Campania "Luigi Vanvitelli", Caserta, Italy.

Purpose: Beckwith-Wiedemann syndrome (BWS) is a developmental disorder caused by dysregulation of the imprinted gene cluster of chromosome 11p15.5 and often associated with loss of methylation (LOM) of the imprinting center 2 (IC2) located in KCNQ1 intron 10. To unravel the etiological mechanisms underlying these epimutations, we searched for genetic variants associated with IC2 LOM. Read More

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http://dx.doi.org/10.1038/s41436-018-0416-7DOI Listing
January 2019

Human ether‑à‑go‑go‑related gene mutation L539fs/47‑hERG leads to cell apoptosis through the endoplasmic reticulum stress pathway.

Int J Mol Med 2019 Jan 2. Epub 2019 Jan 2.

Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Institute of Cardiovascular Channelopathy, Key Laboratory of Molecular Cardiology, Xi'an, Shaanxi 710061, P.R. China.

Congenital long QT syndrome (LQTS) is a cardiac channelopathy that often results in fatal arrhythmias. LQTS mutations not only lead to abnormal myocardial electrical activities but are associated with heart contraction abnormalities, cardiomyopathy and congenital heart defects. In vivo and in vitro studies have found that LQTS mutations are associated with cardiomyocyte apoptosis, cardiac developmental disorders and even embryonic mortality. Read More

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http://www.spandidos-publications.com/10.3892/ijmm.2019.4049
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http://dx.doi.org/10.3892/ijmm.2019.4049DOI Listing
January 2019
3 Reads

Implantation of Cardioverter-Defibrillator in Children With Long-QT Syndrome: Assessment of Indications, Efficacy, and Safety Based on 10-Year Experience.

Kardiologiia 2018 Dec 25;58(12):52-58. Epub 2018 Dec 25.

Clinical Institute of Pediatrics named after Academician Y. E. Veltishev; RNIMU after N.I. Pirogov.

Purpose: to assess specificities of course of the long-QT syndrome in children before and after implantation of cardioverter-defibrillator (ICD), and optimization of indications to ICD-therapy.

Materials And Methods: We included in this study 48 children with long-QT syndrome from 44 unrelated families (28 boys and 20 girls), who underwent ICD implantation at the mean age 11.8±3. Read More

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http://dx.doi.org/10.18087/cardio.2018.12.10191DOI Listing
December 2018

Probing the Dynamics and Structural Topology of Reconstituted Human KCNQ1 Voltage Sensor Domain (Q1-VSD) in Lipid Bilayers using EPR Spectroscopy.

Biochemistry 2019 Jan 8. Epub 2019 Jan 8.

KCNQ1 (Kv7.1 or KvLQT1) is a potassium ion channel protein found in the heart, ear and other tissues. In complex with the KCNE1 accessory protein it plays a role during the repolarization phase of the cardiac action potential. Read More

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http://dx.doi.org/10.1021/acs.biochem.8b01042DOI Listing
January 2019

Calmodulinopathy: Functional Effects of CALM Mutations and Their Relationship With Clinical Phenotypes.

Front Cardiovasc Med 2018 11;5:176. Epub 2018 Dec 11.

Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy.

In spite of the widespread role of calmodulin (CaM) in cellular signaling, CaM mutations lead specifically to cardiac manifestations, characterized by remarkable electrical instability and a high incidence of sudden death at young age. Penetrance of the mutations is surprisingly high, thus postulating a high degree of functional dominance. According to the clinical patterns, arrhythmogenesis in CaM mutations can be attributed, in the majority of cases, to either prolonged repolarization (as in long-QT syndrome, LQTS phenotype), or to instability of the intracellular Ca store (as in catecholamine-induced tachycardias, CPVT phenotype). Read More

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http://dx.doi.org/10.3389/fcvm.2018.00176DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6297375PMC
December 2018

Predictors of β-blocker adherence in cardiac inherited disease.

Open Heart 2018 16;5(2):e000877. Epub 2018 Dec 16.

Department of Psychological Medicine, The University of Auckland, Auckland, New Zealand.

Objective: The cardiac inherited disease (CID) population has suboptimal adherence to long-term β-blocker therapy, which is known to be a risk for sudden cardiac death. This study aimed to identify the clinical and psychosocial variables associated with non-adherence in this population.

Methods: 130 individuals (aged 16-81 years, median: 54) from the New Zealand Cardiac Inherited Disease Registry taking β-blockers participated: 65 (50%) long QT syndrome, 42 (32%) hypertrophic cardiomyopathy and 23 (18%) other. Read More

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http://openheart.bmj.com/lookup/doi/10.1136/openhrt-2018-000
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http://dx.doi.org/10.1136/openhrt-2018-000877DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6307606PMC
December 2018
1 Read

A trafficking-deficient KCNQ1 mutation, T587M, causes a severe phenotype of long QT syndrome by interfering with intracellular hERG transport.

J Cardiol 2018 Dec 24. Epub 2018 Dec 24.

Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan. Electronic address:

Background: KCNQ1-T587M is a C-terminal mutation correlated with severe phenotypes of long QT syndrome (LQTS). However, functional analysis of KCNQ1 channels with the T587M mutation showed a mild genotype in the form of haploinsufficiency in a heterologous expression system. This study sought to explore the molecular mechanism underlying the phenotype-genotype dissociation of LQTS patients carrying the KCNQ1-T587M mutation. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S09145087183035
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http://dx.doi.org/10.1016/j.jjcc.2018.10.011DOI Listing
December 2018
4 Reads

Long QT syndrome caveolin-3 mutations differentially modulate K 4 and Ca 1.2 channels to contribute to action potential prolongation.

J Physiol 2018 Dec 27. Epub 2018 Dec 27.

Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison. 1111, Highland Ave, Madison, WI, 53705-2275.

Key Points: Mutations in the caveolae scaffolding protein, caveolin-3 (Cav3), have been linked to the long QT type 9 inherited arrhythmia syndrome (LQT9), and the cause of underlying action potential duration prolongation is incompletely understood. Here, we show that LQT9 Cav3 mutations, F97C and S141R, cause mutation-specific gain of function effects on Ca 1.2-encoded L-type Ca channels responsible for I and cause loss of function effects on heterologously expressed K 4. Read More

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http://dx.doi.org/10.1113/JP276014DOI Listing
December 2018

Dynamic QT Changes in Long QT Syndrome Type 8.

Circ J 2018 Dec 22. Epub 2018 Dec 22.

Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science.

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http://dx.doi.org/10.1253/circj.CJ-18-0984DOI Listing
December 2018

Molecular autopsy: using the discovery of a novel de novo pathogenic variant in the KCNH2 gene to inform healthcare of surviving family.

Heliyon 2018 Dec 8;4(12):e01015. Epub 2018 Dec 8.

Molecular Genetics Laboratory, New York City Office of Chief Medical Examiner, USA.

Background: Molecular testing of the deceased (Molecular Autopsy) is an overlooked area in the United States healthcare system and is not covered by medical insurance, leading to ineffective care for surviving families of thousands of sudden unexpected natural deaths each year. We demonstrated the precision management of surviving family members through the discovery of a novel pathogenic variant in a decedent.

Methods: Forensic investigation and molecular autopsy were performed on an 18-year-old female who died suddenly and unexpectedly. Read More

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http://dx.doi.org/10.1016/j.heliyon.2018.e01015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6288419PMC
December 2018
2 Reads

Isoproterenol suppresses recurrent torsades de pointes in a patient with long QT syndrome type 2.

HeartRhythm Case Rep 2018 Dec 5;4(12):576-579. Epub 2018 Sep 5.

Penn State Heart & Vascular Institute, Penn State Hershey Health, Hershey, Pennsylvania.

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https://linkinghub.elsevier.com/retrieve/pii/S22140271183024
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http://dx.doi.org/10.1016/j.hrcr.2018.08.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6301889PMC
December 2018
1 Read

Calmodulinopathy: A Novel, Life-Threatening Clinical Entity Affecting the Young.

Front Cardiovasc Med 2018 6;5:175. Epub 2018 Dec 6.

Istituto Auxologico Italiano, IRCCS, Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, Milan, Italy.

Sudden cardiac death (SCD) in the young may often be the first manifestation of a genetic arrythmogenic disease that had remained undiagnosed. Despite the significant discoveries of the genetic bases of inherited arrhythmia syndromes, there remains a measurable fraction of cases where in-depth clinical and genetic investigations fail to identify the underlying SCD etiology. A few years ago, 2 cases of infants with recurrent cardiac arrest episodes, due to what appeared to be as a severe form of long QT syndrome (LQTS), came to our attention. Read More

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http://dx.doi.org/10.3389/fcvm.2018.00175DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6291462PMC
December 2018
1 Read

Long-Term Follow-Up of Patients With Short QT Syndrome: Clinical Profile and Outcome.

J Am Heart Assoc 2018 Dec;7(23):e010073

1 First Department of Medicine Faculty of Medicine University Medical Centre Mannheim (UMM) University of Heidelberg Mannheim Germany.

Background Short QT syndrome ( SQTS ) is a rare inheritable disease associated with sudden cardiac death. Data on long-term outcomes of families with SQTS are limited. Methods and Results Seventeen patients with SQTS in 7 independent families (48% men; median age, 42. Read More

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https://www.ahajournals.org/doi/10.1161/JAHA.118.010073
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http://dx.doi.org/10.1161/JAHA.118.010073DOI Listing
December 2018
4 Reads

Determination and Interpretation of the QT Interval.

Circulation 2018 Nov;138(21):2345-2358

Heart Center, Department of Clinical and Experimental Cardiology (A.S.V., K.V.V.L., N.H., S.e.K., M.H.A.S., H.M.J.S., A.A.M.W., P.G.P.), Amsterdam UMC, University of Amsterdam, The Netherlands.

Background: Long QT syndrome (LQTS) is associated with potentially fatal arrhythmias. Treatment is very effective, but its diagnosis may be challenging. Importantly, different methods are used to assess the QT interval, which makes its recognition difficult. Read More

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http://dx.doi.org/10.1161/CIRCULATIONAHA.118.033943DOI Listing
November 2018
7 Reads

High-Throughput Functional Evaluation of KCNQ1 Decrypts Variants of Unknown Significance.

Circ Genom Precis Med 2018 Nov;11(11):e002345

Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL (C.G.V., R.R.D., K.L.F., S.L.G., F.P., J.-M.D., A.L.G.).

Background: The explosive growth in known human gene variation presents enormous challenges to current approaches for variant classification that have implications for diagnosis and treatment of many genetic diseases. For disorders caused by mutations in cardiac ion channels as in congenital arrhythmia syndromes, in vitro electrophysiological evidence has high value in discriminating pathogenic from benign variants, but these data are often lacking because assays are cost, time, and labor intensive.

Methods: We implemented a strategy for performing high-throughput functional evaluations of ion channel variants that repurposed an automated electrophysiological recording platform developed previously for drug discovery. Read More

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http://dx.doi.org/10.1161/CIRCGEN.118.002345DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6309341PMC
November 2018
4 Reads

Recurrent Torsades with Refractory QT Prolongation in a 54-Year-Old Man.

Am J Case Rep 2018 Dec 20;19:1515-1518. Epub 2018 Dec 20.

Critical Care Services, Tripler Army Medical Center, Honolulu, HI, USA.

BACKGROUND QT prolongation is a common, easily overlooked clinical problem with potentially dire consequences. Drug-induced and congenital forms are not mutually exclusive, but are treated differently. Here, we present a case of cryptogenic underlying congenital long QT syndrome (cLQTS) successfully treated with isoproterenol, a drug contraindicated in most congenital forms of this condition. Read More

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https://www.amjcaserep.com/abstract/index/idArt/912326
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http://dx.doi.org/10.12659/AJCR.912326DOI Listing
December 2018
6 Reads

Predicting Patient Response to the Antiarrhythmic Mexiletine Based on Genetic Variation: Personalized Medicine for Long QT Syndrome.

Circ Res 2018 Dec 18. Epub 2018 Dec 18.

Biomedical Engineering, Washington University in St. Louis.

Rationale: Mutations in the SCN5A gene, encoding the α subunit of the Nav1.5 channel, cause a life-threatening form of cardiac arrhythmia, Long QT Syndrome Type 3 (LQT3). Mexiletine, which is structurally related to the Na channel-blocking anesthetic lidocaine, is used to treat LQT3 patients. Read More

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http://dx.doi.org/10.1161/CIRCRESAHA.118.314050DOI Listing
December 2018
1 Read

Anesthetic Considerations for Pediatric Patients With Congenital Long QT Syndrome.

J Cardiothorac Vasc Anesth 2018 Nov 12. Epub 2018 Nov 12.

Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Johns Hopkins All Children's Hospital, St. Petersburg, FL.

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http://dx.doi.org/10.1053/j.jvca.2018.11.005DOI Listing
November 2018
1 Read

Anti-Ro52 antibody acts on the S5-pore linker of hERG to chronically reduce channel expression.

Cardiovasc Res 2018 Dec 13. Epub 2018 Dec 13.

Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Canada.

Aims: The human ether-a-go-go-related gene (hERG) encodes the rapidly activating delayed rectifier potassium channel (IKr). Malfunction of hERG/IKr is the primary cause of acquired long QT syndrome (LQTS), an electrical disorder of the heart that can cause arrhythmias and sudden death. Patients with autoimmune diseases display a high incidence of LQTS. Read More

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http://dx.doi.org/10.1093/cvr/cvy310DOI Listing
December 2018

[ECG pearl: acquired long QT syndrome].

Orv Hetil 2018 Sep;159(39):1607-1610

I. Belgyógyászati Osztály - Kardiológia, Uzsoki utcai Kórház Budapest.

Authors report the case of a patient with drug-induced long QT syndrome. This case highlights the importance of ECG signs of LQTS that may lead to torsade de pointes tachycardia. The patient received the QT prolonging moxifloxacine and the QT remained long even after the offending drug was discontinued. Read More

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http://dx.doi.org/10.1556/650.2018.31021DOI Listing
September 2018

Exome sequencing identifies a novel nonsense mutation of Ring Finger Protein 207 in a Chinese family with Long QT syndrome and syncope.

J Hum Genet 2018 Dec 12. Epub 2018 Dec 12.

Department of Cell Biology, The School of Life Sciences, Central South University, Changsha, 410013, China.

Long QT syndrome (LQTS) is a rare inherited arrhythmia disease characterized by a prolonged QT interval on 12-lead electrocardiograms. It is the crucial factor to induce syncope, ventricular fibrillation, and even sudden cardiac death. Previous studies have proved that mutations of ion channels-related genes play an important role in LQTS patients. Read More

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http://dx.doi.org/10.1038/s10038-018-0549-1DOI Listing
December 2018

Family Relationships Associated With Communication and Testing for Inherited Cardiac Conditions.

West J Nurs Res 2018 Dec 12:193945918817039. Epub 2018 Dec 12.

2 The University of Iowa, Iowa City, IA, USA.

The purpose of this study was to identify characteristics of family relationships associated with communication of genetic risk and testing behaviors among at-risk relatives in families with an inherited cardiac condition. Data were collected from 53 patients and parents of children with an inherited cardiac condition through interviews, pedigrees, and surveys. Associations were examined among family relationship characteristics and whether at-risk relatives were informed about their risk and tested for disease. Read More

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http://dx.doi.org/10.1177/0193945918817039DOI Listing
December 2018

Exercise worsening of electromechanical disturbances: A predictor of arrhythmia in long QT syndrome.

Clin Cardiol 2018 Dec 9. Epub 2018 Dec 9.

Institute of Public Health and Clinical Medicine, Umea University, Umea, Sweden.

Background: Electromechanical (EM) coupling heterogeneity is significant in long QT syndrome (LQTS), particularly in symptomatic patients; EM window (EMW) has been proposed as an indicator of interaction and a better predictor of arrhythmia than QTc.

Hypothesis: To investigate the dynamic response of EMW to exercise in LQTS and its predictive value of arrhythmia.

Methods: Forty-seven LQTS carriers (45 ± 15 years, 20 with arrhythmic events), and 35 controls underwent exercise echocardiogram. Read More

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https://onlinelibrary.wiley.com/doi/abs/10.1002/clc.23132
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http://dx.doi.org/10.1002/clc.23132DOI Listing
December 2018
5 Reads

Clinical and genetic profile of congenital long QT syndrome in Hong Kong: a 20-year experience in paediatrics.

Hong Kong Med J 2018 Dec 3. Epub 2018 Dec 3.

Department of Paediatric Cardiology, Queen Mary Hospital, Pokfulam, Hong Kong.

Introduction: Congenital long QT syndrome (LQTS) is a genetically transmitted cardiac channelopathy that can lead to sudden cardiac death. This study aimed to report the clinical and genetic characteristics of all young patients diagnosed with LQTS in the only tertiary paediatric cardiology centre in Hong Kong.

Methods: This is a retrospective review of all paediatric and young adult patients diagnosed at our centre with LQTS from January 1997 to December 2016. Read More

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http://dx.doi.org/10.12809/hkmj187487DOI Listing
December 2018
1 Read

Interleukin-6 inhibition of hERG underlies risk for acquired long QT in cardiac and systemic inflammation.

PLoS One 2018 6;13(12):e0208321. Epub 2018 Dec 6.

Cardiovascular Research Program, VA New York Harbor Healthcare System, Brooklyn, New York, United States of America.

Increased proinflammatory interleukin-6 (IL-6) levels are associated with acquired long QT-syndrome (LQTS) in patients with systemic inflammation, leading to higher risks for life-threatening polymorphic ventricular tachycardia such as Torsades de Pointes. However, the functional and molecular mechanisms of this association are not known. In most cases of acquired LQTS, the target ion channel is the human ether-á-go-go-related gene (hERG) encoding the rapid component of the delayed rectifier K current, IKr, which plays a critical role in cardiac repolarization. Read More

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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0208321PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6283635PMC
December 2018
2 Reads

Safety of Sports for Young Patients With Implantable Cardioverter-Defibrillators.

Circ Arrhythm Electrophysiol 2018 Nov;11(11):e006305

Yale University School of Medicine, New Haven, CT (J.D., C.B., L.S., F.L., R.J.L.).

Background: Despite safety concerns, many young patients with implantable cardioverter-defibrillators (ICDs) participate in sports. We undertook a prospective, multinational registry to determine the incidence of serious adverse events because of sports participation. The primary end points were death or resuscitated arrest during sports or injury during sports because of arrhythmia or shock. Read More

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http://dx.doi.org/10.1161/CIRCEP.118.006305DOI Listing
November 2018
6 Reads

Medical Castration is a Rare but Possible Trigger of Torsade de Pointes and Ventricular Fibrillation.

Int Heart J 2018 Dec 5. Epub 2018 Dec 5.

Department of Cardiovascular Medicine, Faculty of Medical Sciences, University of Fukui.

Prostate cancer is the most common non-cutaneous malignancy in men and has been steadily rising in an aging society. Medical castration therapy is effective for metastatic prostate cancer, but the proarrhythmic properties have not been reported. We present a 71-year-old Japanese man with metastasis prostate cancer that, during medical castration therapy, had torsades de pointes (TdP) with a QT prolongation and ventricular fibrillation (VF). Read More

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https://www.jstage.jst.go.jp/article/ihj/advpub/0/advpub_18-
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http://dx.doi.org/10.1536/ihj.18-127DOI Listing
December 2018
4 Reads

Control of voltage-driven instabilities in cardiac myocytes with memory.

Chaos 2018 Nov;28(11):113122

Department of Medicine (Cardiology), University of California, Los Angeles, California 90095, USA.

Sudden cardiac death is known to be associated with dynamical instabilities in the heart, and thus control of dynamical instabilities is considered a potential therapeutic strategy. Different control methods were developed previously, including time-delayed feedback pacing control and constant diastolic interval pacing control. Experimental, theoretical, and simulation studies have examined the efficacy of these control methods in stabilizing action potential dynamics. Read More

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http://dx.doi.org/10.1063/1.5040854DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6274634PMC
November 2018
2 Reads

The role of mexiletine in the management of long QT syndrome.

J Electrocardiol 2018 Nov - Dec;51(6):1061-1065. Epub 2018 Aug 31.

Arrhythmia Unit, Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China; Lankenau Institute for Medical Research, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA. Electronic address:

Congenital long QT syndrome (LQTS) is a hereditary cardiac disorder characterized by QT-interval prolongation and T-wave abnormalities on electrocardiogram (ECG), and is associated with an increased risk of torsade de pointes and sudden cardiac death. Beta-blocker medication is effective in most patients except those with a very slow heart rate. Increased late sodium currents (INa-L) can result in bradycardia-dependent QT prolongation. Read More

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http://dx.doi.org/10.1016/j.jelectrocard.2018.08.035DOI Listing
August 2018
1 Read

How to fluorescently label the potassium channel: A case in hERG.

Curr Med Chem 2018 Nov 28. Epub 2018 Nov 28.

Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (MOE), School of Pharmacy, Shandong University, Jinan, Shandong 250012. China.

hERG (Human ether-a-go-go-related gene) potassium channel, which plays an essential role in cardiac action potential repolarization, is responsible for inherited and drug-induced long QT syndrome. Recently, the Cryo-EM structure capturing the open conformation of hERG channel was determined, thus pushing the study on hERG channel at 3.8 Å resolution. Read More

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http://dx.doi.org/10.2174/0929867326666181129094455DOI Listing
November 2018
11 Reads

Protective Effect of Acquired Long QT Syndrome in Takotsubo Syndrome.

Intern Med J 2018 Nov 26. Epub 2018 Nov 26.

First Department of Medicine, Faculty of Medicine, University Medical Centre Mannheim (UMM), University of Heidelberg, Mannheim, Germany.

Background: Clinical variables that predict long-term mortality and recurrence of Takotsubo syndrome (TTS) are not completely understoodas the role of acquired QTc interval prolongation.

Methods And Results: QTc intervals were analysed in 105 patients presenting with symptoms of TTS. These patients were included in an ongoing retrospective cohort database. Read More

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http://doi.wiley.com/10.1111/imj.14169
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http://dx.doi.org/10.1111/imj.14169DOI Listing
November 2018
8 Reads

Support vector machine-based assessment of the T-wave morphology improves long QT syndrome diagnosis.

Europace 2018 Nov;20(suppl_3):iii113-iii119

Department of Biomedical Engineering, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands.

Aims: Diagnosing long QT syndrome (LQTS) is challenging due to a considerable overlap of the QTc-interval between LQTS patients and healthy controls. The aim of this study was to investigate the added value of T-wave morphology markers obtained from 12-lead electrocardiograms (ECGs) in diagnosing LQTS in a large cohort of gene-positive LQTS patients and gene-negative family members using a support vector machine.

Methods And Results: A retrospective study was performed including 688 digital 12-lead ECGs recorded from genotype-positive LQTS patients and genotype-negative relatives at their first visit. Read More

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https://academic.oup.com/europace/article/20/suppl_3/iii113/
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http://dx.doi.org/10.1093/europace/euy243DOI Listing
November 2018
8 Reads

Caveolin-3 Microdomain: Arrhythmia Implications for Potassium Inward Rectifier and Cardiac Sodium Channel.

Front Physiol 2018 9;9:1548. Epub 2018 Nov 9.

Cellular and Molecular Arrhythmia Research Program, University of Wisconsin-Madison, Madison, WI, United States.

In human cardiac ventricular myocytes, caveolin-3 functions as a scaffolding and regulatory protein for signaling molecules and compartmentalizes ion channels. Our lab has recently explored this sub-cellular microdomain and found that potassium inward rectifier Kir2.x is found in association with caveolin-3. Read More

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http://dx.doi.org/10.3389/fphys.2018.01548DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6238080PMC
November 2018

A bilobal model of Ca-dependent inactivation to probe the physiology of L-type Ca channels.

J Gen Physiol 2018 Dec 23;150(12):1688-1701. Epub 2018 Nov 23.

Institute for Computational Medicine, Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD

L-type calcium channels (LTCCs) are critical elements of normal cardiac function, playing a major role in orchestrating cardiac electrical activity and initiating downstream signaling processes. LTCCs thus use feedback mechanisms to precisely control calcium (Ca) entry into cells. Of these, Ca-dependent inactivation (CDI) is significant because it shapes cardiac action potential duration and is essential for normal cardiac rhythm. Read More

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http://dx.doi.org/10.1085/jgp.201812115DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6279366PMC
December 2018
7 Reads

Dynamic Electrocardiographic Abnormalities Captured in Timothy Syndrome.

JACC Clin Electrophysiol 2018 Nov;4(11):1486-1487

Department of Pediatrics, Children's Heart Centre, Division of Cardiology, British Columbia Children's Hospital, Vancouver, British Columbia, Canada. Electronic address:

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http://dx.doi.org/10.1016/j.jacep.2018.06.019DOI Listing
November 2018
2 Reads

Variation of Electrocardiogram Features Across Sleep Stages in Healthy Controls and in Patients with Sleep Apnea Hypopnea Syndrome.

Int Heart J 2018 Nov 20. Epub 2018 Nov 20.

School of Engineering, Sun Yat-Sen University.

Sleep apnea hypopnea syndrome (SAHS) is an independent risk factor for various cardiovascular diseases. Electrocardiogram (ECG) features such as the RR, PR, QT, QTc, Tpe intervals and the Tpe/QT, Tpe/QTc ratios are used to predict and study cardiovascular diseases. It is not clear whether regular patterns of PR and Tpe-related features across sleep stages exist in SAHSs or healthy controls nor whether sleep stages affect the short- and long-range influences of respiratory events on ECG indices. Read More

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http://dx.doi.org/10.1536/ihj.18-076DOI Listing
November 2018
8 Reads

[Analysis of the KCNQ1 gene mutation in 2 families with congenital long QT syndrome type 1 in Xinjiang Uygur Autonomous Region].

Zhonghua Xin Xue Guan Bing Za Zhi 2018 Nov;46(11):868-873

Pacing and Electrophysiology Department, First Affiliated Hospital of Xinjiang Medical University, Urumqi 830000, China.

Present study analyzed the association betwen the postassium voltage-gated channel KQT-like subfamily member 1 gene (KCNQ1) mutation and the clinical and the electrocardiographic features in 2 pedigrees with congenital long QT syndrome type 1 (LQT1) in Xinjiang Uygur Autonomous Region. Three family members were diagnosed as LQT1 patients in 2 Uygur congenital LQT1 families, these 3 LQT1 patients served as long QT group, 24 Uygur healthy volunteers served as control group. Electrocardiogram (ECG) and the gene detection were applied to compare the ECG and molecular genetic features between the long QT group and control group, and to explore the relationship between the KCNQ1 gene mutation and the clinical and the electrocardiographic features in these 2 families with congenital long QT syndrome type 1. Read More

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http://dx.doi.org/10.3760/cma.j.issn.0253-3758.2018.11.010DOI Listing
November 2018
5 Reads

[Performance of interpreting the variants of long QT syndrome according ACMG guidelines by four clinical gene screening agencies from Beijing].

Zhonghua Xin Xue Guan Bing Za Zhi 2018 Nov;46(11):857-861

Cardiology Center of Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Center for Cardiovascular Diseases & Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing 100029, China.

To analyze the interpretation results on the pathogenic classification of KCNH2 variants and SCN5A variants of long QT syndrome (LQTS) based on American College of Medical Genetics and Genomics (ACMG) guidelines by 4 clinical gene screening agencies from Beijing. Pathogenic classification of 16 variants in KCNH2 and SCN5A was made by 4 clinical gene screening agencies from Beijing based on ACMG guideline. Krippendorff's alpha was used to assess the inter-agency variation consistency. Read More

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http://dx.doi.org/10.3760/cma.j.issn.0253-3758.2018.11.008DOI Listing
November 2018
6 Reads

Lack of modulatory effect of the SCN5A R1193Q polymorphism on cardiac fast Na+ current at body temperature.

PLoS One 2018 12;13(11):e0207437. Epub 2018 Nov 12.

Laboratory for Biological Information Processing, Graduate School of Science and Engineering, University of Toyama, Toyama City, Toyama, Japan.

SCN5A encodes the main subunit of the NaV1.5 channel, which mediates the fast Na+ current responsible for generating cardiac action potentials. The single nucleotide polymorphism SCN5A(R1193Q), which results in an amino acid replacement in the subunit, is common in East Asia. Read More

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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0207437PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6231685PMC
November 2018
1 Read

Mechanisms Underlying the Actions of Antidepressant and Antipsychotic Drugs That Cause Sudden Cardiac Arrest.

Arrhythm Electrophysiol Rev 2018 Aug;7(3):199-209

Lankenau Institute for Medical Research Wynnewood, PA, USA.

A number of antipsychotic and antidepressant drugs are known to increase the risk of ventricular arrhythmias and sudden cardiac death. Based largely on a concern over the development of life-threatening arrhythmias, a number of antipsychotic drugs have been temporarily or permanently withdrawn from the market or their use restricted. While many antidepressants and antipsychotics have been linked to QT prolongation and the development of torsade de pointes arrhythmias, some have been associated with a Brugada syndrome phenotype and the development of polymorphic ventricular arrhythmias. Read More

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https://www.aerjournal.com/articles/antidepressant-antipsych
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http://dx.doi.org/10.15420/aer.2018.29.2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6141916PMC
August 2018
6 Reads

Long-QT Syndrome and Competitive Sports.

Arrhythm Electrophysiol Rev 2018 Aug;7(3):187-192

University of Rennes, Department of Sports Medicine University Hospital of Rennes, Inserm, LTSI-UMR 1099 Rennes, France.

Long QT syndrome (LQTS) is an inherited channelopathy which exposes athletes to a risk of sudden cardiac death. Diagnosis is more difficult in this population because: the QT interval is prolonged by training; and the extreme bradycardia frequently observed in athletes makes the QT correction formula less accurate. Based on limited clinical data which tend to demonstrate that exercise, especially swimming, is a trigger for cardiac events, participation in any competitive sports practice is not supported by 2005 European guidelines. Read More

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https://www.aerjournal.com/articles/long-qt-syndrome-and-com
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http://dx.doi.org/10.15420/aer.2018.39.3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6141947PMC
August 2018
9 Reads

QT Prolongation and Malignant Arrhythmia: How Serious a Problem?

Eur Cardiol 2017 Dec;12(2):112-120

First University Department of Cardiology, Hippokration Hospital Athens, Greece.

QT prolongation constitutes one of the most frequently encountered electrical disorders of the myocardium. This is due not only to the presence of several associated congenital syndrome but also, and mainly, due to the QT-prolonging effects of several acquired conditions, such as ischaemia and heart failure, as well as multiple medications from widely different categories. Propensity of repolarization disturbances to arrhythmia appears to be inherent in the function of and electrophysiology of the myocardium. Read More

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https://www.ecrjournal.com/articles/qt-prolongation-and-mali
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http://dx.doi.org/10.15420/ecr.2017:16:1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6223357PMC
December 2017
9 Reads

Epilepsy in patients with long QT syndrome type 1: A Norwegian family.

Epilepsy Behav Case Rep 2018 9;10:118-121. Epub 2018 Oct 9.

Department of Neurology, Oslo University Hospital - Rikshospitalet, PO Box 4950, Nydalen, 0424 Oslo, Norway.

The congenital long QT syndrome (cLQTS) is an inherited cardiac disorder and is associated with sudden cardiac death. We describe a Norwegian family with mutations within the gene causing cLQTS type 1 (LQT1) and epilepsy. The index patient had Jervell and Lange-Nielsen-syndrome (JLNS) with deafness and recurrent episodes of cardiac arrhythmia. Read More

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http://dx.doi.org/10.1016/j.ebcr.2018.09.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6215028PMC
October 2018
1 Read

A Hiccup in Hiccup Management: Cardiac Arrest from Previously Undiagnosed Congenital Long QT Syndrome.

Case Rep Emerg Med 2018 10;2018:5023954. Epub 2018 Oct 10.

Department of Emergency Medicine, University Hospitals Cleveland Medical Center & Case Western Reserve University, Cleveland, OH 44106, USA.

We report the case of a person who went into cardiac arrest after being given chlorpromazine for hiccups and was subsequently diagnosed with congenital Long QT Syndrome. Long QT Syndrome is an uncommon, congenital condition that carries a high risk of sudden cardiac death. Clinicians need to recognize the risk that chlorpromazine may prolong the QTc and prepare to manage potential complications. Read More

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http://dx.doi.org/10.1155/2018/5023954DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6199886PMC
October 2018
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Sudden cardiac arrest in patients without overt heart disease: a limited value of next generation sequencing.

Pol Arch Intern Med 2018 12 7;128(12):721-730. Epub 2018 Nov 7.

INTRODUCTION Unexplained sudden cardiac arrest (SCA), occurs in up to 10% of patients and is often attributed to an inherited arrhythmia syndrome. Family screening and genetic testing may help clarify the cause of unexplained SCA. OBJECTIVES We aimed to assess the usefulness of clinical evaluation and genetic testing in patients after unexplained SCA and in their families. Read More

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http://pamw.pl/en/node/4366
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http://dx.doi.org/10.20452/pamw.4366DOI Listing
December 2018
6 Reads

A personalized approach to long QT syndrome.

Curr Opin Cardiol 2019 Jan;34(1):46-56

Department of Pediatrics, Pediatric Cardiology, University of Utah, Primary Children's Hospital, Salt Lake City, Utah, USA.

Purpose Of Review: Our purpose is to provide an update on the new clinical and genetic aspects of long QT syndrome (LQTS). LQTS is the most common channelopathy and a cause of syncope and sudden death in the young. Although there are 17 types of LQTS, most patients have types 1 or 2 which are due to mutations in KCNQ1 and KCNH2 (encoding for the cardiac potassium channels), and type 3 which is due to a mutation in SCN5A (encoding for the sodium channel). Read More

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http://dx.doi.org/10.1097/HCO.0000000000000587DOI Listing
January 2019
8 Reads

Discordant results about QT prolongation in patients with Turner syndrome.

Anatol J Cardiol 2018 11;20(5):307-308

Department of Cardiology, Koþuyolu Kartal Training and Research Hopital; Ýstanbul-Turkey.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6280277PMC
http://dx.doi.org/10.14744/AnatolJCardiol.2018.27164DOI Listing
November 2018