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https://www.readbyqxmd.com/read/29739726/new-onset-seizures-in-a-patient-with-long-qt-syndrome-lqts2-and-a-pathogenic-carboxyl-terminus-frameshift-variant-of-the-kcnh2-gene
#1
Katherine Zarroli, Henry Querfurth
In patients with Long QT Syndrome (LQTS), mutations in the potassium channel KCNH2 gene increase seizure susceptibility with missense mutations involving the pore region of the gene acting as a positive predictor of seizures. Seizures are less commonly reported in patients with carboxyl (C')-terminus mutations. This case report describes a young man who presented with syncope followed by a first seizure and was found to have LQTS caused by a pathogenic carboxyl-terminus deletion/frameshifting mutation of the KCNH2 gene...
May 5, 2018: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
https://www.readbyqxmd.com/read/29725305/development-of-a-high-throughput-flow-cytometry-assay-to-monitor-defective-trafficking-and-rescue-of-long-qt2-mutant-herg-channels
#2
Scott A Kanner, Ananya Jain, Henry M Colecraft
Long QT Syndrome (LQTS) is an acquired or inherited disorder characterized by prolonged QT interval, exertion-triggered arrhythmias, and sudden cardiac death. One of the most prevalent hereditary LQTS subtypes, LQT2, results from loss-of-function mutations in the hERG channel, which conducts I Kr , the rapid component of the delayed rectifier K+ current, critical for cardiac repolarization. The majority of LQT2 mutations result in Class 2 deficits characterized by impaired maturation and trafficking of hERG channels...
2018: Frontiers in Physiology
https://www.readbyqxmd.com/read/29723683/beyond-the-length-and-look-of-repolarization-defining-the-non-qtc-electrocardiographic-profiles-of-patients-with-congenital-long-qt-syndrome
#3
Conor M Lane, J Martijn Bos, Ram K Rohatgi, Michael J Ackerman
BACKGROUND: Little is known about the spectrum and prevalence of ECG features beyond the length and morphology of repolarization in patients with congenital long QT syndrome (LQTS). OBJECTIVE: To characterize the full ECG phenotype of LQTS patients and evaluate differences by age and LQTS genotype. METHODS: Retrospective review of 943 patients with LQTS (57% female, median age 25 years; IQR 9 - 34 years) was performed. Comprehensive analysis of their initial evaluation ECG was performed using definitions outlined in Heart Rhythm Society guidelines...
April 30, 2018: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/29707106/inhibition-of-aldose-reductase-2-by-a-benzofuroxane-derivative-bf-5m-increases-the-expression-of-kcne1-kcnq1-in-high-glucose-cultured-h9c2-cardiac-cells-and-sudden-cardiac-death
#4
Maria Consiglia Trotta, Monica Salerno, Anna Lisa Brigida, Vincenzo Monda, Antonietta Messina, Carmela Fiore, Roberto Avola, Renato Bernardini, Francesco Sessa, Gabriella Marsala, Guido N Zanghì, Giovanni Messina, Michele D'Amico, Clara Di Filippo
Long QT syndrome (LQTS) is characterized by prolonged QT interval, leading to sudden cardiac death. Hyperglycemia is an important risk factor for LQTS, inhibiting the cardiac rapid component delayed rectifier K+ current (Iks), responsible for QT interval. We previously showed that the new ALR2 inhibitor BF-5m supplies cardioprotection from QT prolongation induced by high glucose concentration in the medium, reducing QT interval prolongation and preserving morphology. Here we investigated the effects of BF-5m on cell cytotoxicity and viability in H9c2 cells, and on cellular potassium ion channels expression...
April 3, 2018: Oncotarget
https://www.readbyqxmd.com/read/29706893/determinants-of-isoform-specific-gating-kinetics-of-herg1-channel-combined-experimental-and-simulation-study
#5
Laura L Perissinotti, Pablo M De Biase, Jiqing Guo, Pei-Chi Yang, Miranda C Lee, Colleen E Clancy, Henry J Duff, Sergei Y Noskov
IKr is the rapidly activating component of the delayed rectifier potassium current, the ion current largely responsible for the repolarization of the cardiac action potential. Inherited forms of long QT syndrome (LQTS) (Lees-Miller et al., 1997) in humans are linked to functional modifications in the Kv11.1 (hERG) ion channel and potentially life threatening arrhythmias. There is little doubt now that hERG-related component of IKr in the heart depends on the tetrameric (homo- or hetero-) channels formed by two alternatively processed isoforms of hERG, termed hERG1a and hERG1b...
2018: Frontiers in Physiology
https://www.readbyqxmd.com/read/29688407/mental-stress-test-a-rapid-simple-and-efficient-test-to-unmask-long-qt-syndrome
#6
Pauline Etienne, François Huchet, Nathalie Gaborit, Julien Barc, Aurélie Thollet, Florence Kyndt, Béatrice Guyomarch, Hervé Le Marec, Flavien Charpentier, Jean-Jacques Schott, Richard Redon, Vincent Probst, Jean-Baptiste Gourraud
Aims: QT prolongation during mental stress test (MST) has been associated with familial idiopathic ventricular fibrillation. In long QT syndrome (LQTS), up to 30% of mutation carriers have normal QT duration. Our aim was to assess the QT response during MST, and its accuracy in the diagnosis of concealed LQTS. Methods and results: All patients who are carrier of a KCNQ1 or KCNH2 mutations without QT prolongation were enrolled. A control group was constituted of patients with negative exercise and epinephrine tests...
April 20, 2018: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/29672598/long-qt-molecular-autopsy-in-sudden-unexplained-death-in-the-young-1-40-years-old-lessons-learnt-from-an-eight-year-experience-in-new-zealand
#7
Luciana Marcondes, Jackie Crawford, Nikki Earle, Warren Smith, Ian Hayes, Paul Morrow, Tom Donoghue, Amanda Graham, Donald Love, Jonathan R Skinner
BACKGROUND: To review long QT syndrome molecular autopsy results in sudden unexplained death in young (SUDY) between 2006 and 2013 in New Zealand. METHODS: Audit of the LQTS molecular autopsy results, cardiac investigations and family screening data from gene-positive families. RESULTS: During the study period, 365 SUDY cases were referred for molecular autopsy. 128 cases (35%) underwent LQTS genetic testing. 31 likely pathogenic variants were identified in 27 cases (21%); SCN5A (14/31, 45%), KCNH2 (7/31, 22%), KCNQ1 (4/31, 13%), KCNE2 (3/31, 10%), KCNE1 (2/31, 7%), KCNJ2 (1/31, 3%)...
2018: PloS One
https://www.readbyqxmd.com/read/29660751/-exposure-therapy-with-the-help-of-a-wearable-defibrillator-device-used-in-the-treatment-of-severe-obsessive-compulsive-disorder-and-congenital-lqts-an-example-for-interdisciplinary-treatment
#8
Fabian Sinowatz, Clemens Jilek, Ulrich Voderholzer, Ulrich Cuntz, Martin Greetfeld, Petra Hopfner, Jürgen Pache
We report on a case of a young female suffering from both obsessive-compulsive disorder (OCD) and a severe underlying cardiac disease. Due to the somatic comorbidity, treatment according to guidelines with exposure and reaction prevention was not initially conducted, due to potentially fatal risks to the patient. However, through collaboration with a cardiology clinic, we were able to find an innovative solution which allowed for the continuation of the exposure therapy. This case report demonstrates a successful interdisciplinary collaboration and is intended to sensitize the reader to the need for checking for somatic contraindications before conducting exposure therapy...
April 16, 2018: Psychotherapie, Psychosomatik, Medizinische Psychologie
https://www.readbyqxmd.com/read/29660035/the-preventable-burden-of-work-related-ill-health
#9
P Cocco, R Agius
Background: The fraction of ill-health overall attributable to occupational conditions has not been extensively evaluated, thus contributing to the perception of a lesser relevance of education and research in occupational health in respect to other fields of medical research and practice. Aims: To assess the relevance of work-related conditions on the aetiology of human ill-health in different health domains. Methods: We extracted the risk estimates associated with heritability and with occupational risk factors for chronic lymphocytic leukaemia (CLL), major depressive disorder (MDD) and long QT syndrome (LQTS) from 13 published international reports...
April 12, 2018: Occupational Medicine
https://www.readbyqxmd.com/read/29650123/interplay-between-genetic-substrate-qtc-duration-and-arrhythmia-risk-in-patients-with-long-qt-syndrome
#10
Andrea Mazzanti, Riccardo Maragna, Gaetano Vacanti, Nicola Monteforte, Raffaella Bloise, Maira Marino, Lorenzo Braghieri, Patrick Gambelli, Mirella Memmi, Eleonora Pagan, Massimo Morini, Alberto Malovini, Martin Ortiz, Luciana Sacilotto, Riccardo Bellazzi, Lorenzo Monserrat, Carlo Napolitano, Vincenzo Bagnardi, Silvia G Priori
BACKGROUND: Long QT syndrome (LQTS) is a common inheritable arrhythmogenic disorder, often secondary to mutations in the KCNQ1, KCNH2, and SCN5A genes. The disease is characterized by a prolonged ventricular repolarization (QTc interval) that confers susceptibility to life-threatening arrhythmic events (LAEs). OBJECTIVES: This study sought to create an evidence-based risk stratification scheme to personalize the quantification of the arrhythmic risk in patients with LQTS...
April 17, 2018: Journal of the American College of Cardiology
https://www.readbyqxmd.com/read/29648704/abnormal-ventricular-repolarization-in-long-qt-syndrome-carriers-is-related-to-short-left-ventricular-filling-time-and-attenuated-stroke-volume-response-during-exercise
#11
Dafni Charisopoulou, George Koulaouzidis, Annika Rydberg, Michael Y Henein
BACKGROUND: Long QT syndrome (LQTS) carriers are characterized by abnormal ventricular repolarization, prolonged systole, and mechanical dispersion. Prolonged left ventricular (LV) systole has been shown to result in disproportionate shortening of LV filling in other conditions. The aim of this study was to assess LV filling, diastolic function, and stroke volume (SV) response to dynamic exercise, in a group of LQTS carriers. METHODS: Forty-seven LQTS carriers (45 ± 15 years, 20 symptomatic) and 35 healthy individuals underwent bicycle stress echocardiogram...
April 12, 2018: Echocardiography
https://www.readbyqxmd.com/read/29625280/long-qt-syndrome-type-5-lite-defining-the-clinical-phenotype-associated-with-the-potentially-pro-arrhythmic-p-asp85asn-kcne1-common-genetic-variant
#12
Conor Lane, John R Giudicessi, Dan Ye, David J Tester, Ram K Rohatgi, J Martijn Bos, Michael J Ackerman
BACKGROUND: Long QT syndrome (LQTS) genetic test reports commonly exclude potentially pro-arrhythmic common variants such as p.Asp85Asn-KCNE1. OBJECTIVE: To determine if a discernible phenotype is associated with p.Asp85Asn-KCNE1 and if relatively common KCNE1 variants underlie transient QT prolongation pedigrees with negative commercial LQTS genetic tests. METHODS: Retrospective review was used to compare demographics, symptomatology, and QT parameters of individuals with p...
April 3, 2018: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/29622001/clinical-and-molecular-genetic-risk-determinants-in-adult-long-qt-syndrome-type-1-and-2-patients-koponen-et-al-follow-up-of-adult-lqts-patients
#13
Mikael Koponen, Aki S Havulinna, Annukka Marjamaa, Annukka M Tuiskula, Veikko Salomaa, Päivi J Laitinen-Forsblom, Kirsi Piippo, Lauri Toivonen, Kimmo Kontula, Matti Viitasalo, Heikki Swan
BACKGROUND: Long QT syndrome (LQTS) is an inherited cardiac disorder predisposing to sudden cardiac death (SCD). We studied factors affecting the clinical course of genetically confirmed patients, in particular those not receiving β-blocker treatment. In addition, an attempt was made to associate risk of events to specific types of KCNQ1 and KCNH2 mutations. METHODS: A follow-up study covering a mean of 18.6 ± 6.1 years was conducted in 867 genetically confirmed LQT1 and LQT2 patients and 654 non-carrier relatives aged 18-40 years...
April 5, 2018: BMC Medical Genetics
https://www.readbyqxmd.com/read/29616748/electrocardiographic-t-wave-parameters-in-families-with-long-qt-syndrome
#14
Grażyna Markiewicz-Łoskot, Ewa Moric-Janiszewska, Bogusław Mazurek, Marianna Łoskot, Mariola Bartusek, Agnieszka Skierska, Lesław Szydłowski
BACKGROUND: T-wave parameters, especially the Tpeak-Tend interval (TpTe), reflect the total dispersion of repolarization, whose amplification may lead to the development of life-threatening ventricular arrhythmias observed in the long QT syndrome (LQTS). OBJECTIVES: The study attempted to evaluate QT, QTp (Q-Tpeak) and TpTe (Tpeak-Tend) intervals in unaffected and affected blood relatives of children with clinically confirmed LQTS as well as to determine whether the values of these repolarization parameters may be used in clinical practice...
March 21, 2018: Advances in Clinical and Experimental Medicine: Official Organ Wroclaw Medical University
https://www.readbyqxmd.com/read/29575607/the-maximum-qtc-of-holter-electrocardiography-in-a-pediatric-population
#15
Yoshiharu Ogawa, Toshikatsu Tanaka, Sachiko Kido
BACKGROUND: The corrected QT interval (QTc) of electrocardiograms (ECGs) at rest and after exercise in a short daytime recording period may be insufficient for the diagnosis and management of long QT syndrome (LQTS) patients, especially for those with LQTS type 2 and 3. Therefore, examining QTc using Holter ECG is important. We designed a method of analyzing QTc in Holter ECG that can be performed in daily clinical practice by combining automatic and manual measurements. METHODS: We reviewed the charts of healthy children (n=210) and LQTS patients (n=35) aged <16 years and analyzed QTc at rest, after exercise, and the maximum QTc of Holter ECG...
March 25, 2018: Pediatrics International: Official Journal of the Japan Pediatric Society
https://www.readbyqxmd.com/read/29573040/f463l-increases-the-potential-of-dofetilide-on-human-ether-a-go-go-related-gene-herg-channels
#16
Gong Cheng, Jine Wu, Wenqi Han, Chaofeng Sun
Mutations in genes related to long QT syndrome (LQTS) is recognized as an independent risk of drug-induced LQTS. We previously screened a mutation F463L in a Chinese patient with LQT2, syncope, and epilepsy. Here, we planned to illustrate how F463L influences the action of dofetilide on hERG channels. F463L-hERG plasmids were transfected into the stable Human Embryonic Kidney 293 (HEK293) cells expressing WT-hERG to generate heterozygous mutant (WT + F463L-hERG). Whole-cell patch clamp and laser confocal scanning microscopy were used to evaluate electrophysiological consequences and the membrane distribution of hERG protein...
March 23, 2018: Microscopy Research and Technique
https://www.readbyqxmd.com/read/29566261/effects-of-trimethoprim-sulfadiazine-and-detomidine-on-the-function-of-equine-k-v-11-1-channels-in-a-two-electrode-voltage-clamp-tevc-oocyte-model
#17
D S Trachsel, M A Tejada, V Groesfjeld Christensen, P J Pedersen, J K Kanters, R Buhl, K Calloe, D A Klaerke
The long QT syndrome (LQTS) is a channelopathy that can lead to severe arrhythmia and sudden cardiac death. Pharmacologically induced LQTS is caused by interaction between drugs and potassium channels, especially the Kv 11.1 channel. Due to such interactions, numerous drugs have been withdrawn from the market or are administered with precautions in human medicine. However, some compounds, such as trimethoprim-sulfonamide combinations are still widely used in veterinarian medicine. Therefore, we investigate the effect of trimethoprim-sulfadiazine (TMS), trimethoprim, sulfadiazine, and detomidine on equine-specific Kv 11...
March 22, 2018: Journal of Veterinary Pharmacology and Therapeutics
https://www.readbyqxmd.com/read/29550106/meta-analysis-of-t-peak-t-end-and-t-peak-t-end-qt-ratio-for-risk-stratification-in-congenital-long-qt-syndrome
#18
Gary Tse, Mengqi Gong, Lei Meng, Cheuk Wai Wong, Stamatis Georgopoulos, George Bazoukis, Martin C S Wong, Konstantinos P Letsas, Vassilios S Vassiliou, Yunlong Xia, Adrian M Baranchuk, Gan-Xin Yan, Tong Liu
BACKGROUND AND OBJECTIVES: Congenital long QT syndrome (LQTS) predisposes affected individuals to ventricular tachycardia/fibrillation (VF/VF), potentially resulting in sudden cardiac death. The Tpeak -Tend interval and the Tpeak -Tend /QT ratio, electrocardiographic markers of dispersion of ventricular repolarization, were proposed for risk stratification but their predictive values in LQTS have been controversial. A systematic review and meta-analysis was conducted to examine the value of Tpeak -Tend intervals and Tpeak -Tend /QT ratios in predicting arrhythmic and mortality outcomes in congenital LQTS...
May 2018: Journal of Electrocardiology
https://www.readbyqxmd.com/read/29532034/mechanisms-of-kcnq1-channel-dysfunction-in-long-qt-syndrome-involving-voltage-sensor-domain-mutations
#19
Hui Huang, Georg Kuenze, Jarrod A Smith, Keenan C Taylor, Amanda M Duran, Arina Hadziselimovic, Jens Meiler, Carlos G Vanoye, Alfred L George, Charles R Sanders
Mutations that induce loss of function (LOF) or dysfunction of the human KCNQ1 channel are responsible for susceptibility to a life-threatening heart rhythm disorder, the congenital long QT syndrome (LQTS). Hundreds of KCNQ1 mutations have been identified, but the molecular mechanisms responsible for impaired function are poorly understood. We investigated the impact of 51 KCNQ1 variants with mutations located within the voltage sensor domain (VSD), with an emphasis on elucidating effects on cell surface expression, protein folding, and structure...
March 2018: Science Advances
https://www.readbyqxmd.com/read/29525288/cardiac-channelopathies-the-role-of-sodium-channel-mutations
#20
REVIEW
Diana João Fonseca, Manuel Joaquim Vaz da Silva
INTRODUCTION AND OBJECTIVES: The importance of sodium channels for the normal electrical activity of the heart is emphasized by the fact that mutations (inherited or de novo) in genes that encode for these channels or their associated proteins cause arrhythmogenic syndromes such as the Brugada syndrome and the long QT syndrome (LQTS). The aim of this study is to conduct a review of the literature on the mutations in the sodium channel complex responsible for heart disease and the implications of a close relationship between genetics and the clinical aspects of the main cardiac channelopathies, namely at the level of diagnosis, risk stratification, prognosis, screening of family members and treatment...
February 2018: Portuguese Journal of Cardiology: An Official Journal of the Portuguese Society of Cardiology
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