keyword
MENU ▼
Read by QxMD icon Read
search

Prolonged QT syndrome

keyword
https://www.readbyqxmd.com/read/28812984/modelling-the-effects-of-quinidine-disopyramide-and-e-4031-on-short-qt-syndrome-variant-3-in-the-human-ventricles
#1
Cunjin Luo, Kuanquan Wang, Henggui Zhang
Short QT syndrome (SQTS) is an inherited cardiac channelopathy, but at present little information is available on its pharmacological treatment. SQT3 variant (linked to the inward rectifier potassium current IK1) of SQTS, results from a gain-of-function mutation (Kir2.1 D172N) in the KCNJ2-encoded channels, which is associated with ventricular fibrillation (VF). Using biophysically-detailed human ventricular computer models, this study investigated the potential effects of quinidine, disopyramide, and E-4031 on SQT3...
August 16, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/28808933/cardiovascular-disease-in-clozapine-treated-patients-evidence-mechanisms-and-management
#2
REVIEW
Kathlyn J Ronaldson
Myocarditis occurs in about 3% of those initiated on clozapine but monitoring reduces the risk of serious outcome. Cardiomyopathy may develop after myocarditis, or from prolonged tachycardia. Monitoring using echocardiography is not deemed cost effective. Tachycardia, orthostatic hypotension and reduced heart rate variability are a group of clozapine-related adverse effects associated with autonomic dysfunction and may have serious consequences in the long term. Elevated heart rate and poor heart rate variability can be treated with a β-blocker or a non-dihydropyridine calcium channel blocker, while orthostatic hypotension can be alleviated by increased fluid intake and abdominal binding, but may require pharmacological intervention...
August 14, 2017: CNS Drugs
https://www.readbyqxmd.com/read/28794082/loss-of-function-kcne2-variants-true-monogenic-culprits-of-long-qt-syndrome-or-proarrhythmic-variants-requiring-secondary-provocation
#3
Jason D Roberts, Andrew D Krahn, Michael J Ackerman, Ram K Rohatgi, Arthur J Moss, Babak Nazer, Rafik Tadros, Brenda Gerull, Shubhayan Sanatani, Yanushi D Wijeyeratne, Alban-Elouen Baruteau, Alison R Muir, Benjamin Pang, Julia Cadrin-Tourigny, Mario Talajic, Lena Rivard, David J Tester, Taylor Liu, Isaac R Whitman, Julianne Wojciak, Susan Conacher, Lorne J Gula, Peter Leong-Sit, Jaimie Manlucu, Martin S Green, Robert Hamilton, Jeff S Healey, Coeli M Lopes, Elijah R Behr, Arthur A Wilde, Michael H Gollob, Melvin M Scheinman
BACKGROUND: Insight into type 6 long-QT syndrome (LQT6), stemming from mutations in the KCNE2-encoded voltage-gated channel β-subunit, is limited. We sought to further characterize its clinical phenotype. METHODS AND RESULTS: Individuals with reported pathogenic KCNE2 mutations identified during arrhythmia evaluation were collected from inherited arrhythmia clinics and the Rochester long-QT syndrome (LQTS) registry. Previously reported LQT6 cases were identified through a search of the MEDLINE database...
August 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/28782696/heritability-in-a-scn5a-mutation-founder-population-with-increased-female-susceptibility-to-non-nocturnal-ventricular-tachyarrhythmia-and-sudden-cardiac-death
#4
Rachel M A Ter Bekke, Aaron Isaacs, Andrei Barysenka, Marije B Hoos, Jan D H Jongbloed, Jan C A Hoorntje, Alfons S M Patelski, Apollonia T J M Helderman-van den Enden, Arthur van den Wijngaard, Monika Stoll, Paul G A Volders
BACKGROUND: Heritable cardiac sodium-channel dysfunction is associated with various arrhythmia syndromes, some predisposing to ventricular fibrillation. Phenotypic diversity among carriers of identical-by-descent mutations is often remarkable, suggesting influences of genetic modifiers. OBJECTIVE: We identified a unique SCN5A-mutation founder population with mixed clinical phenotypes and sudden cardiac death, and investigated the heritability of electromechanical traits besides the SCN5A-mutation effect...
August 3, 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/28768059/-epicatechin-rescues-the-as2-o3-induced-herg-k-channel-deficiency-possibly-through-upregulating-transcription-factor-sp1-expression
#5
Zengxiang Dong, Yuanqi Shi, Lifang Feng, Zhaoqian Shen, Li Fang, Sijia Zheng, Xin Hai, Baoxin Li
(-)-Epicatechin (EPI) has beneficial effects on the cardiovascular disease. The human ether-a-go-go-related gene (HERG) potassium channel is crucial for repolarization of cardiac action potential. Dysfunction of the HERG channel can cause long QT syndrome type 2 (LQT2). Arsenic trioxide (As2 O3 ) has shown efficacy in the treatment of acute promyelocytic leukemia. However, As2 O3 can induce the deficiency of HERG channel and cause LQT2. In this study, we examined whether EPI could rescue the As2 O3 -induced HERG channel deficiency...
August 2, 2017: Journal of Biochemical and Molecular Toxicology
https://www.readbyqxmd.com/read/28765088/the-evolving-role-of-ankyrin-b-in-cardiovascular-disease
#6
Sara N Koenig, Peter J Mohler
Over the last decade, ankyrin-B has been identified as a prominent player in cardiac physiology. Ankyrin-B has a multitude of functions, with roles in expression, localization, and regulation of proteins critical for cardiac excitability, cytoskeletal integrity, and signaling. Further, human ANK2 variants that result in ankyrin-B loss-of-function are associated with 'Ankyrin-B syndrome', a complex cardiac phenotype that may include bradycardia and heart rate variability, conduction block, atrial fibrillation, QT interval prolongation, and potentially fatal catecholaminergic polymorphic ventricular tachycardia...
July 29, 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/28762916/-predictors-of-electrical-myocardial-instability-in-men-with-arterial-hypertension-and-obstructive-sleep-apnea-hypopnea-syndrome
#7
O V Lyshova, N V Borodin, I I Kostenko
OBJECTIVE: To access the detectability of corrected QT interval (QTc) prolongation ( more or equal 450 ms) and increased QT dispersion (QTd more or equal 60 ms) in men with obstructive sleep apnea-hypopnea syndrome (OSAS) and newly diagnosed arterial hypertension (AH). MATERIAL AND METHODS: We included in this study 138 men (mean age 40.5+/-6.9 years, body mass index 34.5+/-4.7 kg/m2, all with more or equal 3 risk factors of AH development, 34% with subclinical target organs damage)...
May 2017: Kardiologiia
https://www.readbyqxmd.com/read/28734073/differential-calcium-sensitivity-in-nav-1-5-mixed-syndrome-mutants
#8
Mena Abdelsayed, Alban-Elouen Baruteau, Karen Gibbs, Shubhayan Sanatani, Andrew D Krahn, Vincent Probst, Peter C Ruben
INTRODUCTION: Inherited arrhythmias may arise from mutations in the SCN5a gene, which encodes the cardiac voltage-gated sodium channel, NaV 1.5. Mutants in NaV 1.5 result in Brugada Syndrome (BrS1), Long-QT Syndrome (LQT3), or mixed syndromes (an overlap of BrS1/LQT3). Exercise is a potential arrhythmogenic trigger in mixed syndromes. We sought to determine the effects of elevated cytosolic calcium, common during exercise, in mixed syndrome NaV 1.5 mutants. METHODS: We used whole-cell patch-clamp to assess the biophysical properties of NaV 1...
July 22, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28728494/the-clinical-significance-of-qt-prolongation-associated-with-tamoxifen-a-review-of-the-literature
#9
Katherine Fung, Julia Imeson, Frances Cusano
Objective To review the literature discussing QT prolongation associated with the use of tamoxifen in order to evaluate the clinical significance. Data sources A search of PubMed (1946 to 2017), MEDLINE (1946 to 2017) and EMBASE (1947 to 2017) was performed using a combination of the following search terms: tamoxifen, estrogen antagonist, selective estrogen receptor modulator, QT prolongation, QT interval, long QT syndrome and torsades de pointes. All searches were limited to human subjects. Reference lists of the literature found were also reviewed but did not reveal any further articles...
January 1, 2017: Journal of Oncology Pharmacy Practice
https://www.readbyqxmd.com/read/28720088/sex-is-a-moderator-of-the-association-between-nos1ap-sequence-variants-and-qtc-in-two-long-qt-syndrome-founder-populations-a-pedigree-based-measured-genotype-association-analysis
#10
Annika Winbo, Eva-Lena Stattin, Ida Maria Westin, Anna Norberg, Johan Persson, Steen M Jensen, Annika Rydberg
BACKGROUND: Sequence variants in the NOS1AP gene have repeatedly been reported to influence QTc, albeit with moderate effect sizes. In the long QT syndrome (LQTS), this may contribute to the substantial QTc variance seen among carriers of identical pathogenic sequence variants. Here we assess three non-coding NOS1AP sequence variants, chosen for their previously reported strong association with QTc in normal and LQTS populations, for association with QTc in two Swedish LQT1 founder populations...
July 18, 2017: BMC Medical Genetics
https://www.readbyqxmd.com/read/28710299/takotsubo-cardiomyopathy-related-complete-heart-block-and-torsades-de-pointes
#11
Faisal Inayat, Hafeez Ul Hassan Virk, Waqas Ullah, Iqra Riaz
Takotsubo cardiomyopathy (TCM) is a relatively recently recognised clinical entity. It frequently mimics acute coronary syndrome and is accompanied by reversible left ventricular apical ballooning in the absence of angiographically significant coronary artery stenosis. TCM is a reversible condition, and the prognosis is usually well. However, in rare instances, it can be associated with life-threatening arrhythmic complications. Herein, we report the case of a patient with TCM who developed complete atrioventricular block followed by QT prolongation and torsades de pointes...
July 14, 2017: BMJ Case Reports
https://www.readbyqxmd.com/read/28679017/a-comparison-of-qtc-intervals-in-alcohol-withdrawal-patients-versus-acute-coronary-syndrome-patients
#12
Timothy Chu, Keith Azevedo, Amy A Ernst, Dusadee Sarangarm, Steven J Weiss
OBJECTIVES: Patients with an alcohol use disorder experiencing acute intoxication or withdrawal may be at risk for electrocardiograph (ECG) abnormalities, including prolongation of repolarization (long QTc [corrected QT]) that may contribute to arrhythmias and may be associated with a threefold increase in the likelihood of sudden cardiac events. Patients with acute coronary syndrome may have prolonged QTc as well. To our knowledge, no previous studies have compared the QTc of ACS with acute ethanol (EtOH) withdrawal syndromes in the emergency department (ED)...
July 2017: Southern Medical Journal
https://www.readbyqxmd.com/read/28670758/congenital-long-qt-syndrome-and-torsade-de-pointes
#13
REVIEW
Nabil El-Sherif, Gioia Turitto, Mohamed Boutjdir
Since its initial description by Jervell and Lange-Nielsen in 1957, the congenital long QT syndrome (LQTS) has been the most investigated cardiac ion channelopathy. A prolonged QT interval in the surface electrocardiogram is the sine qua non of the LQTS and is a surrogate measure of the ventricular action potential duration (APD). Congenital as well as acquired alterations in certain cardiac ion channels can affect their currents in such a way as to increase the APD and hence the QT interval. The inhomogeneous lengthening of the APD across the ventricular wall results in dispersion of APD...
July 2, 2017: Annals of Noninvasive Electrocardiology
https://www.readbyqxmd.com/read/28654209/sensitivity-and-reliability-of-halothane-anaesthetized-microminipigs-to-assess-risk-of-drug-induced-long-qt-syndrome
#14
Xin Cao, Takeshi Wada, Yuji Nakamura, Suchitra Matsukura, Hiroko Izumi-Nakaseko, Kentaro Ando, Atsuhiko T Naito, Atsushi Sugiyama
Using moxifloxacin and terfenadine, which are known to induce benign and malignant QT interval prolongation, respectively, we analysed whether halothane-anaesthetized microminipigs are an appropriate model for assessing the risk of drug-induced long QT syndrome. Moxifloxacin (0.03, 0.3 and 3 mg/kg) and terfenadine (0.03, 0.3 and 3 mg/kg) were intravenously infused over 10 min. with a pause of 20 min. to the halothane-anaesthetized microminipigs (n=4 for each drug). Moxifloxacin decreased the heart rate, whereas it increased the blood pressure in a dose-related manner...
June 27, 2017: Basic & Clinical Pharmacology & Toxicology
https://www.readbyqxmd.com/read/28648896/inhibition-of-cdk5-alleviates-the-cardiac-phenotypes-in-timothy-syndrome
#15
LouJin Song, Seon-Hye E Park, Yehuda Isseroff, Kumi Morikawa, Masayuki Yazawa
L-type calcium channel CaV1.2 plays an essential role in cardiac function. The gain-of-function mutations in CaV1.2 have been reported to be associated with Timothy syndrome, a disease characterized by QT prolongation and syndactyly. Previously we demonstrated that roscovitine, a cyclin-dependent kinase (CDK) inhibitor, could rescue the phenotypes in induced pluripotent stem cell-derived cardiomyocytes from Timothy syndrome patients. However, exactly how roscovitine rescued the phenotypes remained unclear. Here we report a mechanism potentially underlying the therapeutic effects of roscovitine on Timothy syndrome cardiomyocytes...
July 11, 2017: Stem Cell Reports
https://www.readbyqxmd.com/read/28645448/takotsubo-syndrome-presenting-as-syncope-in-a-patient-with-permanent-pacemaker
#16
Bharatraj Banavalikar, Sivasankaran Sivasubramonian, Narayanan Namboodiri, Krishna Kumar Mohanan Nair, Dibya Ranjan Behera, Ajitkumar Valaparambil
Takotsubo syndrome is an acute reversible heart failure syndrome triggered by physical or emotional stress, especially in postmenopausal women. Herein, we describe a case of a 31-year-old pacemaker dependent lady who presented with syncope after she was bereaved of her father. Electrocardiogram at admission revealed ventricular paced rhythm at 60/min, prolonged QT interval and frequent runs of torsades de pointes. Transthoracic echocardiogram and left ventriculogram revealed findings typical of Takotsubo syndrome...
May 18, 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/28632743/in-silico-assessment-of-the-effects-of-quinidine-disopyramide-and-e-4031-on-short-qt-syndrome-variant-1-in-the-human-ventricles
#17
Cunjin Luo, Kuanquan Wang, Henggui Zhang
AIMS: Short QT syndrome (SQTS) is an inherited disorder associated with abnormally abbreviated QT intervals and an increased incidence of atrial and ventricular arrhythmias. SQT1 variant (linked to the rapid delayed rectifier potassium channel current, IKr) of SQTS, results from an inactivation-attenuated, gain-of-function mutation (N588K) in the KCNH2-encoded potassium channels. Pro-arrhythmogenic effects of SQT1 have been well characterized, but less is known about the possible pharmacological antiarrhythmic treatment of SQT1...
2017: PloS One
https://www.readbyqxmd.com/read/28619993/low-extracellular-potassium-prolongs-repolarization-and-evokes-early-afterdepolarization-in-human-induced-pluripotent-stem-cell-derived-cardiomyocytes
#18
Jukka Kuusela, Kim Larsson, Disheet Shah, Chandra Prajapati, Katriina Aalto-Setälä
Long QT syndrome (LQTS) is characterized by a prolonged QT-interval on electrocardiogram and by increased risk of sudden death. One of the most common and potentially life-threatening electrolyte disturbances is hypokalemia, characterized by low concentrations of K(+) Using a multielectrode array platform and current clamp technique, we investigated the effect of low extracellular K(+) concentration ([K(+)]Ex) on the electrophysiological properties of hiPSC-derived cardiomyocytes (CMs) generated from a healthy control subject (WT) and from two symptomatic patients with type 1 of LQTS carrying G589D (LQT1A) or IVS7-2A>G mutation (LQT1B) in KCNQ1 The baseline prolongations of field potential durations (FPDs) and action potential durations (APDs) were longer in LQT1-CMs than in WT-CMs...
June 15, 2017: Biology Open
https://www.readbyqxmd.com/read/28616803/amitriptyline-may-have-possibility-to-induce-brugada-syndrome-rather-than-long-qt-syndrome
#19
Nur Jaharat Lubna, Takeshi Wada, Yuji Nakamura, Koki Chiba, Xin Cao, Hiroko Izumi-Nakaseko, Kentaro Ando, Atsuhiko T Naito, Yoshioki Satoh, Atsushi Sugiyama
Amitriptyline has been reported to induce long QT syndrome in addition to Brugada syndrome. We qualitatively and quantitatively analyzed the potential of amitriptyline to induce these lethal syndromes by using the halothane-anesthetized dogs (n = 6). Amitriptyline was intravenously administered in doses of 0.1, 1 and 10 mg/kg over 10 min every 20 min, which would provide approximately 1, 10 and 100 times higher plasma concentrations than a therapeutic one, respectively. The low dose hardly altered any of the cardiovascular variables...
June 14, 2017: Cardiovascular Toxicology
https://www.readbyqxmd.com/read/28613240/an-isoform-of-nedd4-2-plays-a-pivotal-role-in-electrophysiological-cardiac-abnormalities
#20
Shintaro Minegishi, Tomoaki Ishigami, Hisho Kawamura, Tabito Kino, Lin Chen, Rie Nakashima-Sasaki, Hiroshi Doi, Kengo Azushima, Hiromichi Wakui, Yumi Chiba, Kouichi Tamura
We have previously shown that neural precursor cell-expressed developmentally downregulated gene 4-2 (Nedd4-2) isoforms with a C2 domain are closely related to ubiquitination of epithelial sodium channel (ENaC), resulting in salt-sensitive hypertension by Nedd4-2 C2 targeting in mice. The sodium voltage-gated channel alpha subunit 5 (SCN5A) gene encodes the α subunit of the human cardiac voltage-gated sodium channel (I Na), and the potassium voltage-gated channel subfamily H member 2 (KCNH2) gene encodes rapidly activating delayed rectifier K channels (I Kr)...
June 14, 2017: International Journal of Molecular Sciences
keyword
keyword
1099
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"