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https://www.readbyqxmd.com/read/28550094/safety-of-outpatient-initiation-of-disopyramide-for-obstructive-hypertrophic-cardiomyopathy-patients
#1
Arnon Adler, Dana Fourey, Adaya Weissler-Snir, Waseem Hindieh, Raymond H Chan, Michael H Gollob, Harry Rakowski
BACKGROUND: Disopyramide is effective in ameliorating symptoms in patients with hypertrophic cardiomyopathy; however, its potential for proarrhythmic effect has raised concerns about its use in the ambulatory setting. The risk of initiating disopyramide in this manner has never been evaluated. METHODS AND RESULTS: All charts of patients seen in the outpatient hypertrophic cardiomyopathy clinic between 2010 and 2014 were screened for initiation of disopyramide and data were extracted...
May 26, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28549870/accuracy-of-cyst-versus-solid-diagnosis-in-the-breast-using-quantitative-transmission-qt-ultrasound
#2
Elaine Iuanow, Kathleen Smith, Nancy A Obuchowski, Jennifer Bullen, John C Klock
RATIONAL AND OBJECTIVES: This study aims to evaluate the diagnostic utility of breast imaging using transmission ultrasound. We present readers' accuracy in determining whether a breast lesion is a cyst versus a solid using transmission ultrasound as an adjunct to mammography. MATERIALS AND METHODS: This retrospective multi-reader, multi-case receiver operating characteristic study included 37 lesions seen on mammography and transmission ultrasound. Cyst cases were confirmed as cysts using their appearance on handheld ultrasound...
May 23, 2017: Academic Radiology
https://www.readbyqxmd.com/read/28547743/unremodelled-and-bradycardic-heart-of-the-anaesthetized-rabbit-is-applicable-for-detection-of-drug-induced-torsades-de-pointes-arrhythmias
#3
Mihoko Hagiwara, Seiji Shibuta, Kazuhiro Takada, Ryuichi Kambayashi, Misako Nakajo, Megumi Aimoto, Yoshinobu Nagasawa, Akira Takahara
BACKGROUND AND PURPOSE: Several rabbit proarrhythmia models have been recently developed by genetic or pharmacological methods to suppress the slow component of delayed rectifier K(+) currents in the ventricle, leading to reduction of the repolarization reserve. The present study was designed to characterize a novel rabbit in vivo proarrhythmia model with severe bradycardia caused by acute atrioventricular block (AVB). EXPERIMENTAL APPROACH: Bradycardia was induced in isoflurane-anaesthetized rabbits by creation of AVB using catheter ablation, and the ventricle was electrically driven at 60 beats min(-1) throughout the experiment except when extrasystole appeared...
May 26, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28546456/electrocardiographic-predictors-of-heart-failure-with-reduced-versus-preserved-ejection-fraction-the-multi-ethnic-study-of-atherosclerosis
#4
Wesley T O'Neal, Matylda Mazur, Alain G Bertoni, David A Bluemke, Mouaz H Al-Mallah, Joao A C Lima, Dalane Kitzman, Elsayed Z Soliman
BACKGROUND: Several markers detected on the routine 12-lead ECG are associated with future heart failure events. We examined whether these markers are able to separate the risk of heart failure with reduced ejection fraction (HFrEF) from heart failure with preserved ejection fraction (HFpEF). METHODS AND RESULTS: We analyzed data of 6664 participants (53% female; mean age 62±10 years) from MESA (Multi-Ethnic Study of Atherosclerosis) who were free of cardiovascular disease at baseline (2000-2002)...
May 25, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28544933/cardiotoxic-effect-of-levofloxacin-and-ciprofloxacin-in-rats-with-without-acute-myocardial-infarction-impact-on-cardiac-rhythm-and-cardiac-expression-of-kv4-3-kv1-2-and-nav1-5-channels
#5
Ahmed M Abdelrady, Sawsan A Zaitone, Noha E Farag, Manal S Fawzy, Yasser M Moustafa
Prolongation of QT interval is possible with fluoroquinolones, yet the underlying contributing factors have not been elucidated. Two widely used fluoroquinolone drugs were at the focus of this study in rats with/without acute myocardial dysfunction (AMI) induced by isoproterenol. The effects of levofloxacin and ciprofloxacin on the cardiac mRNA expression of rat Kv4.3, Kv1.2 and Nav1.5 mRNAs were determined. Administration of the two antibiotics produced dose-dependent changes in ECG parameters that were more prominent in rats with AMI than healthy rats; this was accompanied by elevations in serum lactate dehydrogenase and creatine kinase-MB...
May 22, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/28543601/influence-of-meals-and-glycemic-changes-on-qt-interval-dynamics
#6
Brenda Cirincione, Philip T Sager, Donald E Mager
Thorough QT/QTc studies have become an integral part of early drug development programs, with major clinical and regulatory implications. This analysis expands on existing pharmacodynamic models of QT interval analysis by incorporating the influence of glycemic changes on the QT interval in a semimechanistic manner. A total of 21 healthy subjects enrolled in an open-label phase 1 pilot study and provided continuous electrocardiogram monitoring and plasma glucose and insulin concentrations associated with a 24-hour baseline assessment...
May 22, 2017: Journal of Clinical Pharmacology
https://www.readbyqxmd.com/read/28543393/model-based-evaluation-of-exenatide-effects-on-the-qt-interval-in-healthy-subjects-following-continuous-iv-infusion
#7
Brenda Cirincione, Frank LaCreta, Philip Sager, Donald E Mager
Investigation of the cardiovascular proarrhythmic potential of a new chemical entity is now an integral part of drug development. Studies suggest that meals and glycemic changes can influence QT intervals, and a semimechanistic model has been developed that incorporates the effects of changes in glucose concentrations on heart rate (HR) and QT intervals. This analysis aimed to adapt the glucose-HR-QT model to incorporate the effects of exenatide, a drug that reduces postprandial increases in glucose concentrations...
May 22, 2017: Journal of Clinical Pharmacology
https://www.readbyqxmd.com/read/28542844/the-inward-rectifier-current-inhibitor-pa-6-terminates-atrial-fibrillation-and-does-not-cause-ventricular-arrhythmias-in-dedicated-goat-and-dog-models
#8
Yuan Ji, Rosanne Varkevisser, Dragan Opacic, Alexandre Bossu, Marion Kuiper, Jet D M Beekman, Sihyung Yang, Azinwi Phina Khan, Dobromir Dobrev, Niels Voigt, Michael Zhuo Wang, Sander Verheule, Marc A Vos, Marcel A G Van der Heyden
BACKGROUND AND PURPOSE: Inward rectifier current (IK1 ) density increases in atrial fibrillation (AF), shortening effective refractory period and thus promotes atrial reentry. Pentamidine-Analogue 6 (PA-6) is a selective and potent IK1 inhibitor. We tested PA-6 for anti-AF efficacy and potential proarrhythmia, in established large animal models. EXPERIMENTAL APPROACH: PA-6 was applied i.v. in anaesthetized goats with rapid pacing induced AF and anaesthetized chronic AV block dogs...
May 24, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28539979/association-of-metabolic-syndrome-and-electrocardiographic-markers-of-subclinical-cardiovascular-disease
#9
Theodora W Elffers, Renée de Mutsert, Hildo J Lamb, Arie C Maan, Peter W Macfarlane, Ko Willems van Dijk, Frits R Rosendaal, J Wouter Jukema, Stella Trompet
BACKGROUND: The metabolic syndrome (MetS) and its components are well-established risk factors for cardiovascular diseases (CVD). It is inconclusive whether MetS and MetS score are associated with electrocardiographic markers of subclinical CVD, therefore we investigated this in a population without pre-existing CVD. METHODS: We performed a cross-sectional analysis in the Netherlands Epidemiology of Obesity study, a population-based cohort including 6671 participants aged 45-65...
2017: Diabetology & Metabolic Syndrome
https://www.readbyqxmd.com/read/28538401/atrial-fibrillation-was-changed-into-sinus-bradycardia-in-a-ros1-positive-advanced-lung-adenocarcinoma-patient-who-achieved-durable-response-to-crizotinib-a-case-report-and-literature-review
#10
Lan Liu, Jing Wu, Wei Zhao, Mei-Juan Huang
RATIONAL: The c-ros oncogene 1 receptor tyrosine kinase (ROS1)-rearrangements represent a new and rare genetic subtype of non-small-cell lung cancer. In recent years, the use of crizotinib in ROS1-rearranged lung cancer exhibits significant clinical efficacy. Crizotinib is generally well tolerated and the most frequent adverse events include visual disorders, gastrointestinal disturbances, cardiac, and endocrine abnormalities. From a cardiac perspective, crizotinib is associated with 2 main cardiac effects, QT interval prolongation and bradycardia...
May 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28532774/genotype-positive-long-qt-syndrome-in-patients-with-coexisting-congenital-heart-disease
#11
Mohammed A Ebrahim, Matthew R Williams, Suzanne Shepard, James C Perry
Congenital long QT syndrome (LQTS) is characterized by QT prolongation with predisposition to life-threatening arrhythmia. There have been sporadic reports of LQTS coexisting with more common forms of congenital heart disease (CHD). However, the diagnosis of LQTS when CHD is present may be confounded by several common variables including postoperative electromechanical factors predisposing to ventricular arrhythmia, intrinsic, and postoperative QRS abnormalities. This report documents a single-center experience with patients who have both genetically confirmed LQTS and CHD to examine their modes of presentation and factors associated with making the diagnosis of LQTS in this patient population, as well as potential confounding variables that may mask or delay both LQTS diagnosis and initiation of therapy...
April 27, 2017: American Journal of Cardiology
https://www.readbyqxmd.com/read/28527890/mechano-electric-coupling-heterogeneity-in-repolarization-and-the-electrocardiographic-t-wave
#12
REVIEW
V M F Meijborg, C N W Belterman Va, J M T de Bakker, R Coronel, C E Conrath
Stretch influences repolarization by mechano-electric coupling (MEC) and contributes to arrhythmogenesis. Although there is an abundance of research on electrophysiological effects of MEC, it is still unclear how MEC translates to the ECG. We aim to provide an overview of the MEC research focused on the ECG and the underlying changes in electrophysiology. In addition, we present new data on the effect of left ventricular pressure on the electrocardiographic T-wave. We show that an increase in left ventricular pressure leads to prolonged QT-intervals with increased amplitudes of the STT-segment...
May 17, 2017: Progress in Biophysics and Molecular Biology
https://www.readbyqxmd.com/read/28525585/the-effects-of-gender-on-electrical-therapies-for-the-heart-physiology-epidemiology-and-access-to-therapies-a-report-from-the-xii-congress-of-the-italian-association-on-arrhythmology-and-cardiostimulation-aiac
#13
Giuseppe Boriani, Stefano Lorenzetti, Elisabetta Cerbai, Giuseppe Oreto, Gabriele Bronzetti, Vincenzo Livio Malavasi, Alessandro Biffi, Luigi Padeletti, Gianluca Botto, Igor Diemberger
The difference between men and women is clear even just by looking at an electrocardiogram: females present higher resting heart rate, a shorter QRS complex length and greater corrected QT interval. The development of these differences from pubertal age onward suggests that sexual hormones play a key role, although their effect is far from being completely understood. Different incidences between sexes have been reported for many arrhythmias, both ventricular and supraventricular, and also for sudden cardiac death...
May 19, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28515853/qt-prolongation-is-associated-with-increased-mortality-in-end-stage-liver-disease
#14
Sun Moon Kim, Bennet George, Diego Alcivar-Franco, Charles L Campbell, Richard Charnigo, Brian Delisle, Jonathan Hundley, Yousef Darrat, Gustavo Morales, Samy-Claude Elayi, Alison L Bailey
AIM: To determine the prevalence of QT prolongation in a large series of end stage liver disease (ESLD) patients and its association to clinical variables and mortality. METHODS: The QT interval was measured and corrected for heart rate for each patient, with a prolonged QT cutoff defined as QT > 450 ms for males and QT > 470 ms for females. Multiple clinical variables were evaluated including sex, age, serum sodium, international normalized ratio, creatinine, total bilirubin, beta-blocker use, Model for End-Stage Liver Disease (MELD), MELD-Na, and etiology of liver disease...
April 26, 2017: World Journal of Cardiology
https://www.readbyqxmd.com/read/28512721/mid-term-risk-for-subclinical-atherosclerosis-and-chronic-myocarditis-in-children-with-kawasaki-disease-and-transient-coronary-abnormalities
#15
Mansingh Parihar, Surjit Singh, Pandiarajan Vignesh, Anju Gupta, Manojkumar Rohit
There is evidence for premature atherosclerosis and systemic arterial stiffening during follow-up of children with Kawasaki disease (KD) and coronary artery abnormalities (CAA). Moreover, patients with KD may also have subclinical myocardial involvement and inhomogeneous ventricular repolarization. The inhomogeneous ventricular repolarization manifests as increased QT dispersion on electrocardiography. There is a paucity of studies in endothelial dysfunction and QT dispersion in children with KD and transient CAA...
May 17, 2017: Pediatric Cardiology
https://www.readbyqxmd.com/read/28510346/lack-of-effect-of-rivipansel-on-qtc-interval-in-healthy-adult-african-american-male-subjects
#16
Brinda K Tammara, Anna Plotka, Frank E Shafer, David R J Readett, Steve Riley, Joan M Korth-Bradley
Rivipansel is a pan-selectin inhibitor in phase 3 development for the treatment of vaso-occlusive crises in patients with sickle cell disease. This single-dose, randomized, 3-period, 3-treatment (400 mg moxifloxacin open-label, 4 g rivipansel-blinded, and placebo-blinded) crossover study evaluated the effect of rivipansel on the QT/QTc interval in 48 healthy male African American subjects (age, 21-53 years; weight, 60-115 kg). Time-matched, placebo-adjusted change from baseline QT interval using Fridericia's correction method (QTcF) was determined using a repeated-measures mixed-effects model...
May 16, 2017: Journal of Clinical Pharmacology
https://www.readbyqxmd.com/read/28510313/categorization-and-theoretical-comparison-of-quantitative-methods-for-assessing-qt-rr-hysteresis
#17
REVIEW
Hugo Gravel, Daniel Curnier, Nagib Dahdah, Vincent Jacquemet
BACKGROUND: In the human electrocardiogram, there is a lag of adaptation of the QT interval to heart rate changes, usually termed QT/RR hysteresis (QT-hys). Subject-specific quantifiers of QT-hys have been proposed as potential biomarkers, but there is no consensus on the choice of the quantifier. METHODS: A comprehensive literature search was conducted to identify original articles reporting quantifiers of repolarization hysteresis from the surface ECG in humans...
May 16, 2017: Annals of Noninvasive Electrocardiology
https://www.readbyqxmd.com/read/28509723/determinants-of-retinal-microvascular-features-and-their-relationships-in-two-european-populations
#18
Mirna Kirin, Reka Nagy, Thomas J MacGillivray, Ozren Polašek, Caroline Hayward, Igor Rudan, Harry Campbell, Sarah Wild, Alan F Wright, James F Wilson, Veronique Vitart
OBJECTIVES: To examine factors influencing retinal vasculature in two environmentally contrasted, cross-sectional studies of adult participants of European descent and to estimate the extent and specificity of genetic contributions to each retinal vasculature feature. METHODS: Retinal images from 1088 participants in the Orkney Complex Disease Study and 387 in the CROATIA-Korčula study, taken using the same nonmydriatic camera system and graded by the same person, were evaluated...
May 13, 2017: Journal of Hypertension
https://www.readbyqxmd.com/read/28508456/age-and-sex-based-reference-ranges-for-non-invasive-ventricular-repolarisation-parameters
#19
Annabella Braschi, Maurizio G Abrignani, Vincenzo C Francavilla, Vincenzo Abrignani, Giuseppe Francavilla
BACKGROUND: Some electrocardiographic parameters are able to assess indirectly ventricular repolarisation homogeneity. It is consequently essential to discriminate between normal and abnormal values in clinical decision-making. Considering there is still not a consensus about normal cut-off values, the aim of this study was to document reference intervals in all age groups of a healthy population, providing for age- and sex-percentile tables, which can be used easily and quickly in clinical practice...
May 2017: International Journal of Clinical Practice
https://www.readbyqxmd.com/read/28507628/does-vitamin-d-deficiency-effect-heart-rate-variability-in-low-cardiovascular-risk-population
#20
Ahmet Nalbant, Mehmet Bulent Vatan, Perihan Varım, Ceyhun Varım, Tezcan Kaya, Ali Tamer
AIM: This study aimed to evaluate the cardiac autonomic dysfunction and the cardiac arrhythmia risk using heart rate variability parameters in subjects with vitamin D deficiency and low cardiovascular risk. MATERIAL AND METHODS: One hundred five consecutive individuals, 54 patients with low vitamin D status and 51 healthy controls were enrolled in this study. The overall cardiac autonomic tone was quantified by using various heart rate variability parameters included mean RR interval, mean Heart Rate, mean of standard deviations of intervals for 24 hours (SDNN), standard deviation of averages of intervals (SDANN), mean of standard deviation of intervals for 5 minutes (SDNNI), root mean square of difference of successive intervals (rMSSD) and the proportion of intervals differing more than 50 ms (pNN50) values...
April 15, 2017: Open Access Macedonian Journal of Medical Sciences
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