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https://www.readbyqxmd.com/read/29104745/an-adaptive-and-time-efficient-ecg-r-peak-detection-algorithm
#1
Qin Qin, Jianqing Li, Yinggao Yue, Chengyu Liu
R-peak detection is crucial in electrocardiogram (ECG) signal analysis. This study proposed an adaptive and time-efficient R-peak detection algorithm for ECG processing. First, wavelet multiresolution analysis was applied to enhance the ECG signal representation. Then, ECG was mirrored to convert large negative R-peaks to positive ones. After that, local maximums were calculated by the first-order forward differential approach and were truncated by the amplitude and time interval thresholds to locate the R-peaks...
2017: Journal of Healthcare Engineering
https://www.readbyqxmd.com/read/29103053/domperidone-for-hypotension-in-parkinson-s-disease-a-systematic-review
#2
Stephen Bacchi, Ivana Chim, Philippe Kramer, Ronald B Postuma
BACKGROUND: Domperidone is a proposed treatment of orthostatic hypotension (OH) in Parkinson's disease (PD). However, domperidone use in PD is tempered by concerns regarding QT prolongation and ventricular tachyarrhythmia and sudden cardiac death (VT/SCD). OBJECTIVE: The aim is to identify peer-reviewed studies in which either (1) the effect of domperidone on blood pressure in patients with PD, or (2) the adverse effects associated with domperidone use in PD patients has been reported...
2017: Journal of Parkinson's Disease
https://www.readbyqxmd.com/read/29042382/drugs-and-life-threatening-ventricular-arrhythmia-risk-results-from-the-dare-study-cohort
#3
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/28951721/mechanistic-systems-modeling-to-improve-understanding-and-prediction-of-cardiotoxicity-caused-by-targeted-cancer-therapeutics
#4
Jaehee V Shim, Bryan Chun, Johan G C van Hasselt, Marc R Birtwistle, Jeffrey J Saucerman, Eric A Sobie
Tyrosine kinase inhibitors (TKIs) are highly potent cancer therapeutics that have been linked with serious cardiotoxicity, including left ventricular dysfunction, heart failure, and QT prolongation. TKI-induced cardiotoxicity is thought to result from interference with tyrosine kinase activity in cardiomyocytes, where these signaling pathways help to control critical processes such as survival signaling, energy homeostasis, and excitation-contraction coupling. However, mechanistic understanding is limited at present due to the complexities of tyrosine kinase signaling, and the wide range of targets inhibited by TKIs...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28944242/autosomal-recessive-long-qt-syndrome-type-1-in-eight-families-from-saudi-arabia
#5
Amnah Y Bdier, Saleh Al-Ghamdi, Prashant K Verma, Khalid Dagriri, Bandar Alshehri, Omamah A Jiman, Sherif E Ahmed, Arthur A M Wilde, Zahurul A Bhuiyan, Jumana Y Al-Aama
BACKGROUND: One of the most common primary cardiac arrhythmia syndromes is autosomal dominant long QT syndrome, type 1 (LQT1), chiefly caused by mono-allelic mutations in the KCNQ1 gene. Bi-allelic mutations in the KCNQ1 gene are causal to Jervell and Lange-Nielsen syndrome (JLNS), characterized by severe and early-onset arrhythmias with prolonged QTc interval on surface ECG and sensorineural deafness. Occasionally, bi-allelic mutations in KCNQ1 are also found in patients without any deafness, referred to as autosomal recessive long QT syndrome, type 1 (AR LQT1)...
September 2017: Molecular Genetics & Genomic Medicine
https://www.readbyqxmd.com/read/28943016/serum-calcium-and-risk-of-sudden-cardiac-arrest-in-the-general-population
#6
COMPARATIVE STUDY
Hirad Yarmohammadi, Audrey Uy-Evanado, Kyndaron Reinier, Carmen Rusinaru, Harpriya Chugh, Jonathan Jui, Sumeet S Chugh
OBJECTIVE: To evaluate the potential role of low serum Ca levels in the occurrence of sudden cardiac arrest (SCA) in the community. PATIENTS AND METHODS: We compared 267 SCA cases [177 (66%) men] and 445 controls [314 (71%) men] from a large population-based study (catchment population ∼1 million individuals) in the US Northwest from February 1, 2002, through December 31, 2015. Patients were included if their age was 18 years or older with available creatinine clearance (CrCl) and serum electrolyte levels for analyses to enable adjustment for renal function...
October 2017: Mayo Clinic Proceedings
https://www.readbyqxmd.com/read/28919217/population-based-beat-to-beat-qt-analysis-from-holter-recordings-in-the-long-qt-syndrome
#7
Alex Page, Scott McNitt, Xiaojuan Xia, Wojciech Zareba, Jean-Philippe Couderc
The increasing dissemination of wearable ECG recorders (e.g. Holter, patches, and strap sensors) enables the acquisition of large amounts of data during long periods of time. However, the clinical value of these long-term continuous recordings is hindered by the lack of automatic tools to extract clinically relevant information (other than non-sinus and life-threatening rhythms) from such long-term data, particularly when targeting population-based research. In this work, we propose and test a new tool for analyzing beat-to-beat interval measurements and extracting features from Holter ECGs...
August 10, 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/28776165/prolongation-of-the-qtc-interval-in-hiv-infected-individuals-compared-to-the-general-population
#8
Nico Reinsch, Marina Arendt, Marie Henrike Geisel, Christina Schulze, Volker Holzendorf, Anna Warnke, Till Neumann, Norbert H Brockmeyer, Dirk Schadendorf, Lewin Eisele, Raimund Erbel, Susanne Moebus, Karl-Heinz Jöckel, Stefan Esser
OBJECTIVES: Prolonged QT interval is associated with arrhythmias and sudden death. An increased prevalence of QT interval prolongation in human immunodeficiency virus-infected (HIV) subjects was previously described. The impact of different medications and HIV infection itself on the QT interval is rarely investigated in large HIV+ cohorts. METHODS: We compared QT interval measurement in 496 HIV(+) patients of the HIV-HEART study (HIVH) and 992 sex- and age-matched controls of the population-based German Heinz Nixdorf Recall study (HNR)...
October 2017: Infection
https://www.readbyqxmd.com/read/28746337/genome-wide-analysis-of-ivermectin-response-by-onchocerca-volvulus-reveals-that-genetic-drift-and-soft-selective-sweeps-contribute-to-loss-of-drug-sensitivity
#9
Stephen R Doyle, Catherine Bourguinat, Hugues C Nana-Djeunga, Jonas A Kengne-Ouafo, Sébastien D S Pion, Jean Bopda, Joseph Kamgno, Samuel Wanji, Hua Che, Annette C Kuesel, Martin Walker, Maria-Gloria Basáñez, Daniel A Boakye, Mike Y Osei-Atweneboana, Michel Boussinesq, Roger K Prichard, Warwick N Grant
BACKGROUND: Treatment of onchocerciasis using mass ivermectin administration has reduced morbidity and transmission throughout Africa and Central/South America. Mass drug administration is likely to exert selection pressure on parasites, and phenotypic and genetic changes in several Onchocerca volvulus populations from Cameroon and Ghana-exposed to more than a decade of regular ivermectin treatment-have raised concern that sub-optimal responses to ivermectin's anti-fecundity effect are becoming more frequent and may spread...
July 2017: PLoS Neglected Tropical Diseases
https://www.readbyqxmd.com/read/28705431/-effect-of-intermittent-variable-intensity-exercise-on-qt-variation-and-risk-of-sudden-cardiac-death-among-cameroonian-school-adolescents
#10
E C Bika Lele, M N Pepouomi, A Temfemo, J Mekoulou, P Assomo Ndemba, S H Mandengue
INTRODUCTION: Several cases of sudden deaths are observed among students practicing sport and physical activity (SPA). Just few studies have been carried out on the variation of the QT (interval) and risk of sudden death during sporting exercises. AIM: To determine the effect of variable intermittent stress intensity on the variation of QT and the risk of sudden cardiac death. PATIENTS AND METHODS: Form 4, lower sixth and upper sixth students were recruited from a high school in Douala (Cameroon)...
July 10, 2017: Annales de Cardiologie et D'angéiologie
https://www.readbyqxmd.com/read/28699261/npq-t-a-chlorophyll-fluorescence-parameter-for-rapid-estimation-and-imaging-of-non-photochemical-quenching-of-excitons-in-photosystem-ii-associated-antenna-complexes
#11
Stefanie Tietz, Christopher C Hall, Jeffrey A Cruz, David M Kramer
In photosynthesis, light energy is absorbed by light-harvesting complexes and used to drive photochemistry. However, a fraction of absorbed light is lost to non-photochemical quenching (NPQ) that reflects several important photosynthetic processes to dissipate excess energy. Currently, estimates of NPQ and its individual components (qE , qI , qZ and qT ) are measured from pulse-amplitude-modulation (PAM) measurements of chlorophyll fluorescence yield and require measurements of the maximal yield of fluorescence in fully dark-adapted material (Fm ), when NPQ is assumed to be negligible...
August 2017: Plant, Cell & Environment
https://www.readbyqxmd.com/read/28673509/discovery-of-a-new-mexiletine-derived-agonist-of-the-herg-k-channel
#12
Roberta Gualdani, Maria Maddalena Cavalluzzi, Francesco Tadini-Buoninsegni, Giovanni Lentini
The human Ether-a-go-go Related Gene (hERG) potassium channel plays a central role in the rapid component (IKr) of cardiac action potential repolarization phase. A large number of structurally different compounds block hERG and cause a high risk of arrhythmias. Among the drugs that block hERG channel, a few compounds have been identified as hERG channel activators. Such compounds may be useful, at least in theory, for the treatment of long term QT syndrome. Here we describe a new activator of hERG channel, named MC450...
October 2017: Biophysical Chemistry
https://www.readbyqxmd.com/read/28624887/voriconazole-induced-qt-prolongation-among-hemato-oncologic-patients-clinical-characteristics-and-risk-factors
#13
I Gueta, R Loebstein, N Markovits, Y Kamari, H Halkin, G Livni, H Yarden-Bilavsky
PURPOSE: The purpose of this study is to determine the rate of QTcP and associated risk factors in patients treated with voriconazole. METHODS: We conducted a retrospective chart review of all patients treated with voriconazole in a large tertiary center between 2009 and 2015, using paired comparison of QTc intervals on and off voriconazole treatment, adjusted for comorbidities, electrolyte abnormalities, and concurrent medications. RESULTS: Fifty-four patients were included, of whom 53 were diagnosed with oncologic/hemato-oncologic disease...
September 2017: European Journal of Clinical Pharmacology
https://www.readbyqxmd.com/read/28610624/normal-limits-of-the-electrocardiogram-derived-from-a-large-database-of-brazilian-primary-care-patients
#14
Daniel M F Palhares, Milena S Marcolino, Thales M M Santos, José L P da Silva, Paulo R Gomes, Leonardo B Ribeiro, Peter W Macfarlane, Antonio L P Ribeiro
BACKGROUND: Knowledge of the normal limits of the electrocardiogram (ECG) is mandatory for establishing which patients have abnormal ECGs. No studies have assessed the reference standards for a Latin American population. Our aim was to establish the normal ranges of the ECG for pediatric and adult Brazilian primary care patients. METHODS: This retrospective observational study assessed all the consecutive 12-lead digital electrocardiograms of primary care patients at least 1 year old in Minas Gerais state, Brazil, recorded between 2010 and 2015...
June 13, 2017: BMC Cardiovascular Disorders
https://www.readbyqxmd.com/read/28608915/abc-om-pediatrisk-ekg-tolkning
#15
Caroline Fransson, Stefan Johansson, Cecilia Halvorsen
The ABC of paediatric ECG interpretation In paediatric patients, ECG is used as a tool for investigation of arrhythmias, chest pain, syncope, intoxications and congenital heart abnormalities. Paediatric ECGs differ significantly from adult ECGs, and change gradually during childhood, largely because of the changes that start with the transition of foetal circulation at birth. This evolution is most prominent during the first year of life, but it is not until the late adolescent years that the ECG corresponds to that of adults...
June 9, 2017: Läkartidningen
https://www.readbyqxmd.com/read/28590366/effect-of-gwas-identified-genetic-variants-on-maximum-qt-interval-in-patients-with-schizophrenia-receiving-antipsychotic-agents-a-24-hour-holter-ecg-study
#16
Junzo Watanabe, Naoki Fukui, Yutaro Suzuki, Takuro Sugai, Shin Ono, Nobuto Tsuneyama, Mami Saito, Misuzu Tajiri, Toshiyuki Someya
BACKGROUND: Users of antipsychotics (APs) have a risk of sudden cardiac death (SCD). Sudden cardiac death in such patients is thought to be largely due to drug-induced QT prolongation. It has been reported that many subjects with drug-induced torsades de pointes (TdP) have risk alleles associated with subclinical congenital long QT syndrome. METHODS: We investigated the effects of the risk alleles associated with long QT on the QT interval in patients receiving APs using 24-hour Holter electrocardiograms to take into account the circadian fluctuation of QT intervals...
August 2017: Journal of Clinical Psychopharmacology
https://www.readbyqxmd.com/read/28542844/the-inward-rectifier-current-inhibitor-pa-6-terminates-atrial-fibrillation-and-does-not-cause-ventricular-arrhythmias-in-goat-and-dog-models
#17
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: The density of the inward rectifier current (IK1 ) increases in atrial fibrillation (AF), shortening effective refractory period and thus promoting atrial re-entry. The synthetic compound pentamidine analogue 6 (PA-6) is a selective and potent IK1 inhibitor. We tested PA-6 for anti-AF efficacy and potential proarrhythmia, using established models in large animals. EXPERIMENTAL APPROACH: PA-6 was applied i.v. in anaesthetized goats with rapid pacing-induced AF and anaesthetized dogs with chronic atrio-ventricular (AV) block...
August 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28515853/qt-prolongation-is-associated-with-increased-mortality-in-end-stage-liver-disease
#18
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/28509723/determinants-of-retinal-microvascular-features-and-their-relationships-in-two-european-populations
#19
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...
August 2017: Journal of Hypertension
https://www.readbyqxmd.com/read/28500657/modulation-of-kv-11-1-herg-channels-by-5-1h-indazol-5-yl-oxy-methyl-n-4-trifluoromethoxy-phenyl-pyrimidin-2-amine-itp-2-a-novel-small-molecule-activator
#20
Harinath Sale, Samrat Roy, Jayakumar Warrier, Srinivasan Thangathirupathy, Yoganand Vadari, Shruthi K Gopal, Prasad Krishnamurthy, Manjunath Ramarao
BACKGROUND AND PURPOSE: Activators of Kv 11.1 (hERG) channels have potential utility in the treatment of acquired and congenital long QT (LQT) syndrome. Here, we describe a new hERG channel activator, 5-(((1H-indazol-5-yl)oxy)methyl)-N-(4-(trifluoromethoxy)phenyl)pyrimidin-2-amine (ITP-2), with a chemical structure distinct from previously reported compounds. EXPERIMENTAL APPROACH: Conventional electrophysiological methods were used to assess the effects of ITP-2 on hERG1a and hERG1a/1b channels expressed heterologously in HEK-293 cells...
August 2017: British Journal of Pharmacology
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