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Early repolarization

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https://www.readbyqxmd.com/read/28624975/deleterious-acute-and-chronic-effects-of-bradycardic-right-ventricular-apex-pacing-consequences-for-arrhythmic-outcome
#1
T R G Stams, A Dunnink, W M van Everdingen, H D M Beekman, R van der Nagel, B Kok, M F A Bierhuizen, M J Cramer, M Meine, M A Vos
In the chronic complete atrioventricular (AV) block dog (CAVB) model, both bradycardia and altered ventricular activation due to the uncontrolled idioventricular rhythm contribute to ventricular remodeling and the enhanced susceptibility to Torsade de Pointes (TdP) arrhythmias. We investigated the effect of permanent bradycardic right ventricular apex (RVA) pacing on mechanical and electrical remodeling and TdP. In 23 anesthetized dogs, serial experiments were performed at sinus rhythm (SR), acutely after AV block (AAVB) and 3 weeks of remodeling CAVB at a fixed pacing rate of 60/min...
July 2017: Basic Research in Cardiology
https://www.readbyqxmd.com/read/28619993/low-extracellular-potassium-prolongs-repolarization-and-evokes-early-afterdepolarization-in-human-induced-pluripotent-stem-cell-derived-cardiomyocytes
#2
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/28612303/additive-proarrhythmic-effect-of-combined-treatment-with-qt-prolonging-agents
#3
Gerrit Frommeyer, Christina Fischer, Christian Ellermann, Dirk G Dechering, Simon Kochhäuser, Philipp S Lange, Kristina Wasmer, Michael Fehr, Lars Eckardt
Drug combinations may elevate the risk of proarrhythmia. The aim of the present study was to investigate whether combinations of non-cardiovascular agents induce an additive increase in the proarrhythmic risk. In 12 female rabbit hearts, a drug combination of cotrimoxazole (300 µM), ondansetron (5 µM) and domperidone (1 µM) was infused after obtaining baseline data. In another 13 hearts, a combination of cotrimoxazole (300 µM), ondansetron (5 µM) and erythromycin (300 µM) was infused. Monophasic action potentials and ECG displayed a significant QT prolongation in all groups...
June 13, 2017: Cardiovascular Toxicology
https://www.readbyqxmd.com/read/28611679/icariin-a-novel-blocker-of-sodium-and-calcium-channels-eliminates-early-and-delayed-afterdepolarizations-as-well-as-triggered-activity-in-rabbit-cardiomyocytes
#4
Wanzhen Jiang, Mengliu Zeng, Zhenzhen Cao, Zhipei Liu, Jie Hao, Peipei Zhang, Youjia Tian, Peihua Zhang, Jihua Ma
Icariin, a flavonoid monomer from Herba Epimedii, has confirmed pharmacological and biological effects. However, its effects on arrhythmias and cardiac electrophysiology remain unclear. Here we investigate the effects of icariin on ion currents and action potentials (APs) in the rabbit myocardium. Furthermore, the effects of icariin on aconitine-induced arrhythmias were assessed in whole rabbits. Ion currents and APs were recorded in voltage-clamp and current-clamp mode in rabbit left ventricular myocytes (LVMs) and left atrial myocytes (LAMs), respectively...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28606656/divergent-antiarrhythmic-effects-of-resveratrol-and-piceatannol-in-a-whole-heart-model-of-long-qt-syndrome
#5
Christian Ellermann, Julian Wolfes, Simon Kochhäuser, Dirk G Dechering, Florian Reinke, Kristina Wasmer, Lars Eckardt, Gerrit Frommeyer
BACKGROUND: The polyphenol resveratrol and its metabolite piceatannol have beneficial health effects including antiarrhythmic properties in ischemia/reperfusion. The objective of this study was to determine potential antiarrhythmic effects in acquired long-QT-syndrome (LQTS). METHODS AND RESULTS: 26 rabbit hearts were isolated and Langendorff-perfused. The IKr-blocker sotalol (100μM) was infused to mimic LQTS-2. Hearts were assigned to two groups. Sotalol significantly prolonged action potential duration (APD90) and QT-interval in both groups (group 1:APD90: +18ms, p<0...
June 3, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28591770/inferolateral-early-repolarization-among-non-ischaemic-sudden-cardiac-death-victims
#6
Lauri T A Holmström, Mira A Haukilahti, Jani T Tikkanen, Aapo L Aro, Tuomas V Kenttä, Marja-Leena Kortelainen, Heikki V Huikuri, Matti J Junttila
Aim: Inferolateral early repolarization (ER) has been associated with an increased risk of sudden cardiac death (SCD). However, this association is thought to be mainly due to ischaemic SCD. The association of ER and non-ischaemic SCD has not been studied. The aim was to evaluate whether inferolateral ER is associated with non-ischaemic SCD. Methods and results: Study population consists of 275 consecutive victims of non-ischaemic SCD with 12-lead ECG and control group of general population cohort with 10 864 subjects...
June 7, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28569435/the-new-kids-on-the-block-of-arrhythmogenic-disorders-short-qt-syndrome-and-early-repolarization
#7
REVIEW
Andrea Mazzanti, Katherine Underwood, Dmitriy Nevelev, Shanna Kofman, Silvia G Priori
Short QT Syndrome (SQTS) is a one of the rarest inheritable cardiac channelopathy, characterized by an accelerated cardiac repolarization, which is also the substrate for the development of life-threatening ventricular arrhythmias. Up to this date, fewer than 200 SQTS cases have been reported in the literature worldwide. Patients with SQTS may experience a cardiac arrest as early as in the neonatal period or as late as 80 years old. The cumulative probability of experiencing a cardiac arrest by the fifth decade of life approaches 40%, highlighting the importance of early recognition and management...
June 1, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28557343/progression-of-early-repolarization-patterns-at-a-four-year-follow-up-in-a-female-flight-crew-population-implications-for-aviation-medicine
#8
Gwénolé Rohel, Eric Perrier, Aurélien Delluc, Jonathan Monin, Olivier Manen, Philippe Paule, Marie Piquemal, Jacques Mansourati, Ulric Vinsonneau
BACKGROUND: To assess the prevalence, the appearance, and the distribution, as well as the fluctuation over time of early repolarization patterns after four years in a female population derived from the French aviation sector. METHODS: This was a retrospective longitudinal study from 1998 to 2010 of a population of female employees who received a full clinical examination and an electrocardiogram (ECG) upon their recruitment and after a period of four years. RESULTS: A total of 306 women were included (average of 25...
May 30, 2017: Annals of Noninvasive Electrocardiology
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
#9
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/28542428/age-dependent-electrical-and-morphological-remodeling-of-the-drosophila-heart-caused-by-herg-seizure-mutations
#10
Karen Ocorr, Alexander Zambon, Yoav Nudell, Santiago Pineda, Soda Diop, Min Tang, Takeshi Akasaka, Erika Taylor
Understanding the cellular-molecular substrates of heart disease is key to the development of cardiac specific therapies and to the prevention of off-target effects by non-cardiac targeted drugs. One of the primary targets for therapeutic intervention has been the human ether a go-go (hERG) K+ channel that, together with the KCNQ channel, controls the rate and efficiency of repolarization in human myocardial cells. Neither of these channels plays a major role in adult mouse heart function; however, we show here that the hERG homolog seizure (sei), along with KCNQ, both contribute significantly to adult heart function as they do in humans...
May 2017: PLoS Genetics
https://www.readbyqxmd.com/read/28541470/progressive-increase-of-the-tpeak-tend-interval-is-associated-with-ischaemia-induced-ventricular-fibrillation-in-a-porcine-myocardial-infarction-model
#11
Jan E Azarov, Marina M Demidova, Sasha Koul, Jesper van der Pals, David Erlinge, Pyotr G Platonov
Aims: Repolarization indices of ECG have been widely assessed as predictors of ventricular arrhythmias. However, little is known of the dynamic changes of these parameters during continuous monitoring in acute ischaemic episodes. The objective of the study was to evaluate repolarization-related predictors of ventricular fibrillation (VF) during progression of experimental myocardial infarction. Methods and results: Myocardial infarction was induced in 27 pigs by 40-min balloon inflation in the left anterior descending coronary artery, and 12-lead ECG was continuously recorded...
May 24, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28534025/atrial-fibrillation-dynamics-and-ionic-block-effects-in-six-heterogeneous-human-3d-virtual-atria-with-distinct-repolarization-dynamics
#12
Carlos Sánchez, Alfonso Bueno-Orovio, Esther Pueyo, Blanca Rodríguez
Atrial fibrillation (AF) usually manifests as reentrant circuits propagating through the whole atria creating chaotic activation patterns. Little is yet known about how differences in electrophysiological and ionic properties between patients modulate reentrant patterns in AF. The goal of this study is to quantify how variability in action potential duration (APD) at different stages of repolarization determines AF dynamics and their modulation by ionic block using a set of virtual whole-atria human models...
2017: Frontiers in Bioengineering and Biotechnology
https://www.readbyqxmd.com/read/28511782/prevalence-of-early-repolarization-pattern-in-patients-with-lone-atrial-fibrillation
#13
Patrick W McNair, Dan M Benenson, James E Ip, George Thomas, Jim W Cheung, Christopher F Liu, Bruce B Lerman, Steven M Markowitz
BACKGROUND: The objective of this study was to test the association of early repolarization pattern (ER) with lone atrial fibrillation (AF). METHODS: Electrocardiograms (ECGs) were analyzed in blinded fashion in a case-control study of 182 patients with lone AF and 182 controls without AF. RESULTS: Patients with lone AF and controls had similar frequencies of ER pattern (15% vs. 19%, p=0.40). In patients <50years of age, there was also no difference in the percentage of patients with ER in the AF and control groups (17% vs...
April 28, 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/28497823/natural-products-modulating-the-herg-channel-heartaches-and-hope
#14
REVIEW
Jadel M Kratz, Ulrike Grienke, Olaf Scheel, Stefan A Mann, Judith M Rollinger
Covering: 1996-December 2016The human Ether-à-go-go Related Gene (hERG) channel is a voltage-gated potassium channel playing an essential role in the normal electrical activity in the heart. It is involved in the repolarization and termination of action potentials in excitable cardiac cells. Mutations in the hERG gene and hERG channel blockage by small molecules are associated with increased risk of fatal arrhythmias. Several drugs have been withdrawn from the market due to hERG channel-related cardiotoxicity...
May 12, 2017: Natural Product Reports
https://www.readbyqxmd.com/read/28495433/ventricular-and-supraventricular-ectopy-in-subjects-with-early-repolarization
#15
Teresa Trenkwalder, Ryan King, Bernhard M Kaess, Christian Hengstenberg, Heribert Schunkert, Till Ittermann, Stephan B Felix, Mathias Busch, Marcus Dörr, Wibke Reinhard
Early repolarization (ER) is a common electrocardiographic (ECG) finding that is associated with an increased risk of idiopathic ventricular fibrillation and sudden cardiac death. This study investigated whether the presence of ER is a predictor of ventricular and supraventricular ectopy as a marker for electrical instability. Standard 12-lead electrocardiograms of the first follow-up in the population-based Study of Health in Pomerania (SHIP-1) (n = 3,300, age 20 to 79 years) were analyzed to identify subjects with an ER pattern...
April 12, 2017: American Journal of Cardiology
https://www.readbyqxmd.com/read/28493952/a-mutation-in-the-cacna1c-gene-leads-to-early-repolarization-syndrome-with-incomplete-penetrance-a-chinese-family-study
#16
Xin Liu, Yang Shen, Jinyan Xie, Huihui Bao, Qing Cao, Rong Wan, Xiaoming Xu, Hui Zhou, Lin Huang, Zhenyan Xu, Wengen Zhu, Jinzhu Hu, Xiaoshu Cheng, Kui Hong
BACKGROUND: Early repolarization syndrome (ERS) may be a near-Mendelian or an oligogenic disease; however, no direct evidence has been provided to support this theory. METHODS AND RESULTS: We described a large Chinese family with nocturnal sudden cardiac death induced by ERS in most of the young male adults. One missense mutation (p.Q1916R) was found in the major subunit of the L-type calcium channel gene CACNA1C by the direct sequencing of candidate genes. A concomitant gain-of-function variant in the sodium channel gene SCN5A (p...
2017: PloS One
https://www.readbyqxmd.com/read/28491706/radiofrequency-catheter-ablation-for-treatment-of-premature-ventricular-contractions-triggering-ventricular-fibrillation-from-the-right-ventricular-outflow-tract-in-a-patient-with-early-repolarization-syndrome
#17
Jun Kakihara, Masahiko Takagi, Yusuke Hayashi, Hiroaki Tatsumi, Atsushi Doi, Minoru Yoshiyama
No abstract text is available yet for this article.
July 2016: HeartRhythm Case Reports
https://www.readbyqxmd.com/read/28490369/erratum-to-%C3%A2-novel-trigenic-cacna1c-des-mypn-mutations-in-a-family-of-hypertrophic-cardiomyopathy-with-early-repolarization-and-short-qt-syndrome
#18
Yanhong Chen, Hector Barajas-Martinez, Dongxiao Zhu, Xihui Wang, Chonghao Chen, Ruijuan Zhuang, Jingjing Shi, Xueming Wu, Yijia Tao, Weidong Jin, Xiaoyan Wang, Dan Hu
No abstract text is available yet for this article.
May 11, 2017: Journal of Translational Medicine
https://www.readbyqxmd.com/read/28476433/intelligent-use-of-advanced-capabilities-of-diagnostic-ecg-algorithms-in-a-monitoring-environment
#19
Reza Firoozabadi, Richard E Gregg, Saeed Babaeizadeh
A large number of ST-elevation notifications are generated by cardiac monitoring systems, but only a fraction of them is related to the critical condition known as ST-segment elevation myocardial infarction (STEMI) in which the blockage of coronary artery causes ST-segment elevation. Confounders such as acute pericarditis and benign early repolarization create electrocardiographic patterns mimicking STEMI but usually do not benefit from a real-time notification. A STEMI screening algorithm able to recognize those confounders utilizing capabilities of diagnostic ECG algorithms in variation analysis of ST segments helps to avoid triggering a non-actionable ST-elevation notification...
April 25, 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/28464037/pressure-overload-induced-angiotensin-mediated-early-remodeling-in-mouse-heart
#20
Jeremy H Kim, Ya-Ping Jiang, Ira S Cohen, Richard Z Lin, Richard T Mathias
Our previous work on angiotensin II-mediated electrical-remodeling in canine left ventricle, in connection with a long history of other studies, suggested the hypothesis: increases in mechanical load induce autocrine secretion of angiotensin II (A2), which coherently regulates a coterie of membrane ion transporters in a manner that increases contractility. However, the relation between load and A2 secretion was correlative. We subsequently showed a similar or identical system was present in murine heart. To investigate whether the relation between mechanical load and A2-mediated electrical remodeling was causal, we employed transverse aortic constriction in mice to subject the left ventricle to pressure overload for short-term (1 to 2 days) or long-term (1 to 2 weeks) periods...
2017: PloS One
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