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https://www.readbyqxmd.com/read/29048110/morphometric-and-morphologic-parameters-of-the-heart-in-healthy-alouatta-guariba-clamitans-cabrera-1940
#1
Murilo Gomes de Soutello Charlier, Maurício Gianfrancesco Filippi, Carolina Hagy Girotto, Vanessa Lanes Ribeiro, Carlos Roberto Teixeira, Maria Lúcia Gomes Lourenço, Luiz Carlos Vulcano
BACKGROUND: This study aimed at assessing the heart function of one neotropical primate (Alouatta guariba clamitans) kept in captivity using radiography, electrocardiogram (ECG) and Doppler echocardiography. METHODS: Ten adult healthy howler monkeys (A. g. clamitans) were evaluated under general anaesthesia. Vertebral Heart Scores (VHS) were obtained from radiographic studies. Ejection fraction, shortening fraction of left ventricle, left atrial/aortic root ratio, ascending aortic diameter, peak velocity of pulmonary, mitral, tricuspid and aortic blood flow and other values were measured by Doppler echocardiography...
October 19, 2017: Journal of Medical Primatology
https://www.readbyqxmd.com/read/29046645/computational-cardiac-modeling-reveals-mechanisms-of-ventricular-arrhythmogenesis-in-long-qt-syndrome-type-8-cacna1c-r858h-mutation-linked-to-ventricular-fibrillation
#2
Jieyun Bai, Kuanquan Wang, Yashu Liu, Yacong Li, Cuiping Liang, Gongning Luo, Suyu Dong, Yongfeng Yuan, Henggui Zhang
Functional analysis of the L-type calcium channel has shown that the CACNA1C R858H mutation associated with severe QT interval prolongation may lead to ventricular fibrillation (VF). This study investigated multiple potential mechanisms by which the CACNA1C R858H mutation facilitates and perpetuates VF. The Ten Tusscher-Panfilov (TP06) human ventricular cell models incorporating the experimental data on the kinetic properties of L-type calcium channels were integrated into one-dimensional (1D) fiber, 2D sheet, and 3D ventricular models to investigate the pro-arrhythmic effects of CACNA1C mutations by quantifying changes in intracellular calcium handling, action potential profiles, action potential duration restitution (APDR) curves, dispersion of repolarization (DOR), QT interval and spiral wave dynamics...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/29046643/trigger-vs-substrate-multi-dimensional-modulation-of-qt-prolongation-associated-arrhythmic-dynamics-by-a-herg-channel-activator
#3
Michael A Colman, Erick A Perez Alday, Arun V Holden, Alan P Benson
Background: Prolongation of the QT interval of the electrocardiogram (ECG), underlain by prolongation of the action potential duration (APD) at the cellular level, is linked to increased vulnerability to cardiac arrhythmia. Pharmacological management of arrhythmia associated with QT prolongation is typically achieved through attempting to restore APD to control ranges, reversing the enhanced vulnerability to Ca(2+)-dependent afterdepolarisations (arrhythmia triggers) and increased transmural dispersion of repolarisation (arrhythmia substrate) associated with APD prolongation...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/29044094/evaluation-of-tp-e-interval-tp-e-qt-ratio-and-tp-e-qtc-ratio-in-patients-with-mitral-valve-stenosis-before-and-after-balloon-valvuloplasty
#4
Muhammet Dural, Kadir Uğur Mert, Kemal İskenderov
OBJECTIVE: Sympathetic activity increases in patients with mitral stenosis (MS). The association between prolonged Tpeak-Tend (Tp-e) interval and increased sympathetic activity has been demonstrated. This study aimed to evaluate Tp-e interval, Tp-e/QT ratio, and Tp-e/corrected QT interval (QTc) ratio in patients with MS before and after balloon valvuloplasty. METHODS: Thirty patients with severe MS and 30 sex-, body mass index-, and and age-matched healthy control subjects were enrolled...
October 13, 2017: Anatolian Journal of Cardiology
https://www.readbyqxmd.com/read/29042382/drugs-and-life-threatening-ventricular-arrhythmia-risk-results-from-the-dare-study-cohort
#5
Abigail L Coughtrie, Elijah R Behr, Deborah Layton, Vanessa Marshall, A John Camm, Saad A W Shakir
OBJECTIVES: To establish a unique sample of proarrhythmia cases, determine the characteristics of cases and estimate the contribution of individual drugs to the incidence of proarrhythmia within these cases. SETTING: Suspected proarrhythmia cases were referred by cardiologists across England between 2003 and 2011. Information on demography, symptoms, prior medical and drug histories and data from hospital notes were collected. PARTICIPANTS: Two expert cardiologists reviewed data for 293 referred cases: 130 were included...
October 16, 2017: BMJ Open
https://www.readbyqxmd.com/read/29037423/unique-ecg-presentations-and-clinical-management-of-a-symptomatic-lqt2-female-carrying-a-novel-de-novo-kcnh2-mutation
#6
Chunlin Yin, Ping Zhang, Jing Yang, Li Zhang
A 26-year-old woman, 12 days in postpartum, developed recurrent syncope and cardiac arrest. Her ECG revealed QT-prolongation associated with LQT2-specific T-U wave patterns, T wave alternans, long QT-dependent torsade de pointes (TdP) and ventricular fibrillation (VF). She also had intermittent LBBB (80bpm) on alternate beats and RBBB at sinus tachycardia (113bpm). Family genotyping revealed a novel de novo missense mutation G604C of KCNH2. Propranolol slowed heart rate and further prolonged QT interval (610ms) that caused TdP recurrence...
August 17, 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/29037240/kh176-under-development-for-rare-mitochondrial-disease-a-first-in-man-randomized-controlled-clinical-trial-in-healthy-male-volunteers
#7
Saskia Koene, Edwin Spaans, Luc Van Bortel, Griet Van Lancker, Brant Delafontaine, Fabio Badilini, Julien Beyrath, Jan Smeitink
BACKGROUND: Mitochondrial disorders are a clinically, biochemically and genetically heterogeneous group of multi-system diseases, with an unmet medical need for treatment. KH176 is an orally bio-available small molecule under development for the treatment of mitochondrial(-related) diseases. The compound is a member of a new class of drugs, acting as a potent intracellular redox-modulating agent essential for the control of oxidative and redox pathologies. The aim of this randomized, placebo controlled, double-blinded phase 1 study was to test safety, tolerability and pharmacokinetics of single and multiple doses of KH176 in healthy male volunteers...
October 16, 2017: Orphanet Journal of Rare Diseases
https://www.readbyqxmd.com/read/29037160/-homozygous-and-compound-heterozygous-mutation-in-3-turkish-family-with-jervell-and-lange-nielsen-syndrome-case-reports
#8
Fahrettin Uysal, Burcu Turkgenc, Guven Toksoy, Ozlem M Bostan, Elif Evke, Oya Uyguner, Cengiz Yakicier, Hulya Kayserili, Ergun Cil, Sehime G Temel
BACKGROUND: Jervell and Lange-Nielsen syndrome (JLNS) isa recessive model of long QT syndrome which might also be related to possible hearing loss. Although the syndrome has been demonstrated to be originated from homozygous or compound heterozygous mutations in either the KCNQ1 or KCNE1 genes, additional mutations in other genetic loci should be considered, particularly in malignant course patients. CASE PRESENTATIONS: Three patients were admitted into hospital due to recurrent seizures/syncope, intrauterine and postnatal bradycardia respectively; moreover all three patients had congenital sensorineural hearing-loss...
October 16, 2017: BMC Medical Genetics
https://www.readbyqxmd.com/read/29036623/predictors-of-mortality-in-high-risk-patients-with-qt-prolongation-in-a-community-hospital
#9
Charlotte Gibbs, Jacob Thalamus, Kristian Heldal, Øystein Lunde Holla, Kristina H Haugaa, Jan Hysing
Aims: To determine predictors of mortality in patients with corrected QT interval (QTc) ≥ 500 ms in a community hospital. Methods and results: In this retrospective observational study, we searched the electrocardiogram (ECG) database at Telemark Hospital Trust, Norway, from January 2004 to December 2014. Medication, electrolyte abnormalities, and medical conditions known to prolong the QT interval were recorded. From the medical records, we assessed whether the prolonged QTc was noted by the health care providers...
October 3, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/29036559/the-brisk-standing-test-for-long-qt-syndrome-in-prepubertal-school-children-defining-normal
#10
L H P M Filippini, P G Postema, K Zoubin, B J M Hermans, N A Blom, T Delhaas, A A M Wilde
Aims: Long QT syndrome (LQTS) is associated with malignant arrhythmias and sudden death from birth to advanced age. Prolongation of the QT-interval, may however be concealed on standard electrocardiograms (ECG). The brisk-standing-test (BST) was developed to guide LQTS-diagnosis and treatment in adults. We hypothesized that the BST may be used in prepubertal children to identify LQTS subjects. Accordingly, reference values for the BST should be available to prevent incorrect diagnosis and treatment of LQTS...
October 3, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/29036457/feasibility-evaluation-of-long-term-use-of-beta-blockers-and-calcium-antagonists-in-patients-with-brugada-syndrome
#11
Tsukasa Kamakura, Mitsuru Wada, Kohei Ishibashi, Yuko Y Inoue, Koji Miyamoto, Hideo Okamura, Satoshi Nagase, Takashi Noda, Takeshi Aiba, Satoshi Yasuda, Wataru Shimizu, Shiro Kamakura, Kengo Kusano
Aims: Beta-blockers (BBs) and calcium antagonists (CAs) are reported to aggravate ST-segment elevation in some patients with Brugada syndrome (BrS). The feasibility of their long-term use in BrS still remains unknown. We investigated the safety of long-term use of BB and CA in BrS patients. Methods and results: Of the 360 consecutive BrS patients, 29 [5: a history of ventricular fibrillation (VF), 17: syncope, 7: asymptomatic] took BB and/or CA (BB: 22, CA: 8) for more than 1 year for the treatment of co-morbidities such as atrial tachyarrhythmia, vasospastic angina, and neurally mediated syncope...
September 23, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/29035985/qt-corrections-for-long-qt-risk-assessment-implications-for-the-preparticipation-examination
#12
David Hadley, David Hsu, David Pickham, Jonathan A Drezner, Victor F Froelicher
BACKGROUND: Because sudden cardiac death (SCD) in the young mainly occur in individuals with structurally normal hearts, improved screening techniques for detecting inherited arrhythmic diseases are needed. The QT interval is an important screening measurement; however, the criteria for detecting an abnormal QT interval are based on Bazett formula and older populations. OBJECTIVE: To define the normal upper limits for QT interval from the electrocardiograms (ECGs) of healthy young individuals, compare the major correction formula and propose new QT interval thresholds for detecting those at risk of SCD...
October 10, 2017: Clinical Journal of Sport Medicine: Official Journal of the Canadian Academy of Sport Medicine
https://www.readbyqxmd.com/read/29031413/experiences-in-digitizing-and-digitally-measuring-a-paper-based-ecg-archive
#13
Arttu Holkeri, Antti Eranti, Tuomas V Kenttä, Kai Noponen, M Anette E Haukilahti, Tapio Seppänen, M Juhani Junttila, Tuomas Kerola, Harri Rissanen, Markku Heliövaara, Paul Knekt, Aapo L Aro, Heikki V Huikuri
BACKGROUND: No established method for digitizing and digital measuring of paper electrocardiograms (ECG) exists. We describe a paper ECG digitizing and digital measuring process, and report comparability to manual measurements. METHODS: A paper ECG was recorded from 7203 health survey participants in 1978-1980. With specific software, the ECGs were digitized (ECG Trace Tool), and measured digitally (EASE). A sub-sample of 100 ECGs was selected for manual measurements...
September 27, 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/29030380/association-between-qt-interval-components-and-sudden-cardiac-death-the-aric-study-atherosclerosis-risk-in-communities
#14
Wesley T O'Neal, Matthew J Singleton, Jason D Roberts, Larisa G Tereshchenko, Nona Sotoodehnia, Lin Y Chen, Gregory M Marcus, Elsayed Z Soliman
BACKGROUND: Several reports have demonstrated that prolongation of the QT interval is associated with sudden cardiac death (SCD). However, it is unknown whether any of the components within the QT interval are responsible for its association with SCD. METHODS AND RESULTS: We examined the association of the individual QT-interval components (R-wave onset to R-peak, R-peak to R-wave end, ST-segment, T-wave onset to T-peak, and T-peak to T-wave end) with SCD in 12 241 participants (54±5...
October 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/29029798/effect-of-intravenous-ondansetron-on-qtc-interval-in-children-with-gastroenteritis
#15
Robert J Hoffman, Khalid Alansari
BACKGROUND: The potential for ondansetron to cause QT prolongation and fatal dysrhythmia is well-reported, including a 2011 FDA report on the topic. Few clinical trials evaluating this phenomenon in the ED setting exist, and only one is pediatric. OBJECTIVE: We have sought to determine the effect of a standardized dose of intravenous ondansetron on the QTc duration of children under 14years of age treated for gastroenteritis-associated vomiting in a pediatric ED...
October 4, 2017: American Journal of Emergency Medicine
https://www.readbyqxmd.com/read/29029613/right-precordial-directed-electrocardiographical-markers-identify-arrhythmogenic-right-ventricular-cardiomyopathy-in-the-absence-of-conventional-depolarization-or-repolarization-abnormalities
#16
Daniel Cortez, Anneli Svensson, Jonas Carlson, Sharon Graw, Nandita Sharma, Francesca Brun, Anita Spezzacatene, Luisa Mestroni, Pyotr G Platonov
BACKGROUND: Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) carries a risk of sudden death. We aimed to assess whether vectorcardiographic (VCG) parameters directed toward the right heart and a measured angle of the S-wave would help differentiate ARVD/C with otherwise normal electrocardiograms from controls. METHODS: Task Force 2010 definite ARVD/C criteria were met for all patients. Those who did not fulfill Task Force depolarization or repolarization criteria (-ECG) were compared with age and gender-matched control subjects...
October 13, 2017: BMC Cardiovascular Disorders
https://www.readbyqxmd.com/read/29024579/impact-of-the-norepinephrine-prodrug-droxidopa-on-the-qtc-interval-in-healthy-individuals
#17
William B White, L Arthur Hewitt, Ali A Mehdirad
A double-blind, 4-period crossover study (NCT01327066) was conducted to assess the effect of the novel norepinephrine prodrug droxidopa on the QT interval in in healthy subjects. Subjects were randomized to receive a single dose of droxidopa 600 mg (maximal dose) and 2000 mg (supratherapeutic dose) compared with the positive control, moxifloxacin 400 mg, and placebo, each separated by a 3-day washout period. Patients were monitored by continuous Holter monitoring, and electrocardiograms (ECGs) were extracted 0...
October 11, 2017: Clinical Pharmacology in Drug Development
https://www.readbyqxmd.com/read/29023952/pharmacokinetics-and-electrophysiological-effects-of-sotalol-hydrochloride-in-horses
#18
B Broux, D De Clercq, A Decloedt, L Vera, M Devreese, R Gehring, S Croubels, G van Loon
BACKGROUND: Arrhythmias in horses may require long term anti-arrhythmic therapy. Unfortunately, oral anti-arrhythmic drugs for use in horses are currently scarce. In human patients and small animals, sotalol, a β-blocker with class III anti-arrhythmic properties, is often used for long-term treatment. OBJECTIVES: To determine the pharmacokinetics of sotalol at multiple oral dosages in unfasted horses, as well as the effects on electro- and echocardiographic measurements, right atrial and ventricular monophasic action potential (MAP) and effective refractory period (ERP)...
October 10, 2017: Equine Veterinary Journal
https://www.readbyqxmd.com/read/29021866/criteria-for-short-qt-interval-based-on-a-new-qt-heart-rate-adjustment-formula
#19
Simon W Rabkin
BACKGROUND: A short QT interval, within which an increased risk for atrial fibrillation and/or fatal cardiac arrhythmias occurs, has been difficult to define. METHODS: The lower percentiles of a new QTc formula were determined, using a precise mathematical fitting of the QT-heart rate relationship from the ECGs of 13,600 individuals from the NHANES II and III surveys. RESULTS: The QTc interval for persons in the lower fifth percentile, second (2...
October 2017: Journal of Arrhythmia
https://www.readbyqxmd.com/read/29020391/association-between-mitochondrial-dna-copy-number-and-sudden-cardiac-death-findings-from-the-atherosclerosis-risk-in-communities-study-aric
#20
Yiyi Zhang, Eliseo Guallar, Foram N Ashar, Ryan J Longchamps, Christina A Castellani, John Lane, Megan L Grove, Josef Coresh, Nona Sotoodehnia, Leonard Ilkhanoff, Eric Boerwinkle, Nathan Pankratz, Dan E Arking
Aims: Sudden cardiac death (SCD) is a major public health burden. Mitochondrial dysfunction has been implicated in a wide range of cardiovascular diseases including cardiomyopathy, heart failure, and arrhythmias, but it is unknown if it also contributes to SCD risk. We sought to examine the prospective association between mtDNA copy number (mtDNA-CN), a surrogate marker of mitochondrial function, and SCD risk. Methods and results: We measured baseline mtDNA-CN in 11 093 participants from the Atherosclerosis Risk in Communities (ARIC) study...
June 30, 2017: European Heart Journal
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