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https://www.readbyqxmd.com/read/28929393/electrophysiological-characteristics-of-the-rat-azygos-vein-under-electrical-pacing-and-adrenergic-stimulation
#1
Alexandra D Ivanova, Vlad S Kuzmin
Rodent thoracic veins are characterized by an extended myocardial coating. In the present study, the electrical activity in the cardiac tissue of the rat azygos vein (AZV) was investigated for the first time. The atrial-like action potentials (AP) and atrial-like conduction of the excitation were observed in the rat AZV under continuous electrical pacing. Termination of electrical pacing resulted in spontaneous positive shift of resting membrane potential (RMP) in AZV. Boradrenaline induced biphasic effects on RMP in all quiescent AZV preparations but only in 25% preparations-bursts of spontaneous AP, which were suppressed by both α- and β-adrenoreceptor antagonists...
September 19, 2017: Journal of Physiological Sciences: JPS
https://www.readbyqxmd.com/read/28917011/prevalence-predictors-and-prognostic-implications-of-pr-interval-prolongation-in-patients-with-heart-failure
#2
Theodora Nikolaidou, Pierpaolo Pellicori, Jufen Zhang, Syed Kazmi, Kevin M Goode, John G Cleland, Andrew L Clark
AIMS: To determine the prevalence, incidence, predictors, and prognostic implications of PR interval prolongation in patients referred with suspected heart failure. METHODS AND RESULTS: Consecutive patients referred with suspected heart failure were prospectively enrolled. After excluding patients with implantable cardiac devices and atrial fibrillation, 1420 patients with heart failure and reduced ejection fraction (HeFREF) [age: median 71 (interquartile range IQR 63-78) years; men: 71%; NT-ProBNP: 1319 (583-3378) ng/L], 1094 with heart failure and normal ejection fraction (HeFNEF) [age: 76 (70-82) years; men: 47%; NT-ProBNP: 547 (321-1171) ng/L], and 1150 without heart failure [age: 68 (60-75) years; men: 51%; NT-ProBNP: 86 (46-140) ng/L] were included...
September 15, 2017: Clinical Research in Cardiology: Official Journal of the German Cardiac Society
https://www.readbyqxmd.com/read/28911514/defibrillation-for-ventricular-fibrillation-a-shocking-update
#3
REVIEW
Graham Nichol, Michael R Sayre, Federico Guerra, Jeanne Poole
Cardiac arrest is defined as the termination of cardiac activity associated with loss of consciousness, of spontaneous breathing, and of circulation. Sudden cardiac arrest and sudden cardiac death (SCD) are terms often used interchangeably. Most patients with out-of-hospital cardiac arrest have shown coronary artery disease or symptoms during the hour before the event. Cardiac arrest is potentially reversible by cardiopulmonary resuscitation, defibrillation, cardioversion, cardiac pacing, or treatments targeted at the underlying disease (e...
September 19, 2017: Journal of the American College of Cardiology
https://www.readbyqxmd.com/read/28906405/repetitive-optimizing-left-ventricular-pacing-configurations-with-quadripolar-leads-improves-response-to-cardiac-resynchronization-therapy-a-single-center-randomized-clinical-trial
#4
Min Gu, Han Jin, Wei Hua, Xiao-Han Fan, Li-Gang Ding, Jing Wang, Hong-Xia Niu, Chi Cai, Shu Zhang
BACKGROUND: This study aimed to investigate whether repetitive optimizing left ventricular pacing configurations (LVPCs) with quadripolar leads (QUAD) can improve response to cardiac resynchronization therapy (CRT). METHODS: Fifty-two eligible patients were enrolled and 1:1 randomized to either the quadripolar LV leads (QUAD) group or the conventional bipolar leads (CONV) group. In the QUAD group, optimization of LVPC was performed for all patients before discharge and for nonresponders at 3 months follow-up...
September 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28901586/long-term-effects-of-cardiac-resynchronization-therapy-on-electrical-remodeling-in-heart-failure-a-prospective-study
#5
Bharatraj Banavalikar, Anees Thajudeen, Narayanan Namboodiri, Krishna Kumar Mohanan Nair, Abhilash Srivilasam Pushpangadhan, Ajit Kumar Valaparambil
INTRODUCTION: Effects of cardiac resynchronization therapy (CRT) on arrhythmogenicity and sudden death have not been fully ascertained. CRT has been shown to increase transmural dispersion of repolarization (TDR) immediately on implantation, that may favorably remodel on long-term follow-up. However, such a hypothesis has not been prospectively evaluated. METHODS AND RESULTS: We included 35 consecutive patients who underwent CRT implantation between September 2013 & August 2014 (mean age 56...
September 13, 2017: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/28895301/early-leaflet-thrombosis-complicating-transcatheter-implantation-of-a-sapien-3-valve-in-a-native-right-ventricular-outflow-tract
#6
Mounir Riahi, Philipp Blanke, John Webb, Ronald G Carere
A 59-year-old female with Tetralogy of Fallot had a previous complete repair with RVOT patch enlargement. She developed subsequent severe symptomatic (NYHA III) pulmonary regurgitation with severe RV dilatation. She had a concomitant interstitial lung disease secondary to hypersensitivity pneumonitis that precluded her from cardiac surgery. After preprocedural assessment using computed tomography, echocardiography and invasive angiography we decided to implant a 29 mm Edwards Sapien 3 valve without pre-stenting...
September 12, 2017: Catheterization and Cardiovascular Interventions
https://www.readbyqxmd.com/read/28893549/continuous-optimization-of-cardiac-resynchronization-therapy-reduces-atrial-fibrillation-in-heart-failure-patients-results-of-the-adaptive-cardiac-resynchronization-therapy-trial
#7
David Birnie, Harrison Hudnall, Bernd Lemke, Kazutaka Aonuma, Kathy Lai-Fun Lee, Maurizio Gasparini, John Gorcsan, Jeffrey Cerkvenik, David O Martin
BACKGROUND: Data from randomized trials have suggested a modest or no effect of conventional cardiac resynchronization therapy (convCRT) on the incidence of atrial fibrillation (AF). AdaptivCRT (aCRT, Medtronic, Mounds View, MN) is a recently described algorithm for synchronized left ventricular (LV) pacing and continuous optimization of cardiac resynchronization therapy (CRT). OBJECTIVE: We compared the long-term effects of aCRT with convCRT pacing on the incidence of AF...
September 8, 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/28890081/factors-associated-with-postoperative-atrial-fibrillation-and-other-adverse-events-after-cardiac-surgery
#8
Emmanuel Akintoye, Frank Sellke, Roberto Marchioli, Luigi Tavazzi, Dariush Mozaffarian
OBJECTIVE: The study objective was to evaluate the impact of various surgical characteristics and practices on the risk of postoperative atrial fibrillation and other adverse outcomes after cardiac surgery. METHODS: By using the prospectively collected data of patients who underwent cardiac surgery in 28 centers across the United States, Italy, and Argentina, the details of surgery characteristics were collected for each patient and the outcomes, including postoperative atrial fibrillation, major adverse cardiovascular events, and mortality...
August 16, 2017: Journal of Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/28888221/transcatheter-aortic-valve-in-valve-implantation-of-a-corevalve-in-a-jenavalve-prosthesis-a-case-report
#9
Shahram Lotfi, Michael Becker, Ajay Moza, Rüdiger Autschbach, Nikolaus Marx, Jörg Schröder
BACKGROUND: Transcatheter aortic valve implantation has become an accepted treatment modality for inoperable or high-risk surgical patients with symptomatic severe aortic stenosis. CASE PRESENTATION: We report the case of a 70-year-old white man who was treated for severe symptomatic aortic regurgitation using transcatheter aortic valve implantation from the apical approach. Because of recurrent cardiac decompensation 4 weeks after implantation he underwent the implantation of a left ventricular assist device system...
September 10, 2017: Journal of Medical Case Reports
https://www.readbyqxmd.com/read/28887360/initial-clinical-experience-with-a-new-automated-antitachycardia-pacing-algorithm-feasibility-and-safety-in-an-ambulatory-patient-cohort
#10
Raymond Yee, John D Fisher, Ulrika Birgersdotter-Green, Timothy W Smith, David N Kenigsberg, Robert Canby, Troy Jackson, Robert Taepke, Paul DeGroot
BACKGROUND: Antitachycardia pacing (ATP) in implantable cardioverter-defibrillators (ICD) decreases patient shock burden but has recognized limitations. A new automated ATP (AATP) based on electrophysiological first principles was designed. The study objective was to assess the feasibility and safety of AATP in ambulatory ICD patients. METHODS AND RESULTS: Enrolled patients had dual chamber or cardiac resynchronization therapy ICDs, history of ≥1 ICD-treated ventricular tachycardias (VT)/ventricular fibrillation episode, or a recorded, sustained monomorphic VT...
September 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/28886927/suitability-of-cardiac-resynchronisation-therapy-in-patients-with-fontan-circulation-and-congenitally-corrected-transposition-of-the-great-arteries
#11
P Demetriades, A Bell, C Gubran, H Marshall, J de Bono, L Hudsmith
BACKGROUND: Cardiac resynchronisation therapy (CRT) is a well-recognised treatment in systolic heart failure. There is limited evidence in congenital patients with univentricular hearts or systemic right ventricles. In 2014 PACES/HRS published a consensus statement recommending CRT if ventricular ejection fraction (EF)≤35%, QRS duration≥150ms (with RBBB in systemic RV), NYHA II-IV and ventricular dilatation. The incidence of patients meeting these criteria in whom CRT is possible is not known...
September 2, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28883840/modalities-of-ventricular-pacing-for-cardiac-resynchronization-therapy-in-patients-with-heart-failure-a-meta-analysis-and-systematic-review
#12
REVIEW
Ailan Chen, Xinyu Chen, Yuechun Shen, Wanglin Li
INTRODUCTION: This meta-analysis evaluated 14 studies which compared clinical and functional outcomes after different cardiac resynchronization therapy (CRT) modalities. MATERIAL AND METHODS: Relevant studies were selected from the Medline, PubMed, Cochrane, and Google Scholar databases until June 27(th), 2016. We analyzed and compared the clinical outcomes (peak O2 consumption and LVEF) and functional outcomes (6-min walk distance and quality of life (SF-36)) of HF patients who received different CRT modalities with outcomes in patients who received conventional univentricular therapy...
August 2017: Archives of Medical Science: AMS
https://www.readbyqxmd.com/read/28883639/hysteretic-dynamics-of-multi-stable-early-afterdepolarisations-with-repolarisation-reserve-attenuation-a-potential-dynamical-mechanism-for-cardiac-arrhythmias
#13
Kunichika Tsumoto, Yasutaka Kurata, Kazuharu Furutani, Yoshihisa Kurachi
Some cardiovascular and non-cardiovascular drugs frequently cause excessive prolongation of the cardiac action potential (AP) and lead to the development of early afterdepolarisations (EADs), which trigger lethal ventricular arrhythmias. Combining computer simulations in APs with numerical calculations based on dynamical system theory, we investigated stability changes of APs observed in a paced human ventricular myocyte model by decreasing and/or increasing the rapid (I Kr) and slow (I Ks) components of delayed rectifying K(+) current...
September 7, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28878692/optimization-of-an-in-silico-cardiac-cell-model-for-proarrhythmia-risk-assessment
#14
Sara Dutta, Kelly C Chang, Kylie A Beattie, Jiansong Sheng, Phu N Tran, Wendy W Wu, Min Wu, David G Strauss, Thomas Colatsky, Zhihua Li
Drug-induced Torsade-de-Pointes (TdP) has been responsible for the withdrawal of many drugs from the market and is therefore of major concern to global regulatory agencies and the pharmaceutical industry. The Comprehensive in vitro Proarrhythmia Assay (CiPA) was proposed to improve prediction of TdP risk, using in silico models and in vitro multi-channel pharmacology data as integral parts of this initiative. Previously, we reported that combining dynamic interactions between drugs and the rapid delayed rectifier potassium current (IKr) with multi-channel pharmacology is important for TdP risk classification, and we modified the original O'Hara Rudy ventricular cell mathematical model to include a Markov model of IKr to represent dynamic drug-IKr interactions (IKr-dynamic ORd model)...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28878402/genetic-mechanisms-contribute-to-the-development-of-heart-failure-in-patients-with-atrioventricular-block-and-right-ventricular-apical-pacing
#15
Nana Liu, Min Zheng, Shijie Li, Hui Bai, Zhouying Liu, Cui Hong Hou, Shu Zhang, Jielin Pu
Right ventricular apical (RVA) pacing can lead to progressive left ventricular dysfunction and heart failure (HF), even in patients with normal cardiac structure and function. Our study conducted candidate gene screening and lentivirus transfected neonatal rat cardiomyocytes (NRCMs) to explore the genetic and pathogenic mechanisms of RVA pacing induced cardiomyopathy in third degree atrioventricular block (III AVB) patients. We followed 887 III AVB patients with baseline normal cardiac function and RVA pacing...
September 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28877886/pulmonary-right-ventricular-resynchronization-in-congenital-heart-disease-acute-improvement-in-right-ventricular-mechanics-and-contraction-efficiency
#16
Jan Janoušek, Jan Kovanda, Miroslav Ložek, Viktor Tomek, Pavel Vojtovič, Roman Gebauer, Peter Kubuš, Miroslav Krejčíř, Joost Lumens, Tammo Delhaas, Frits Prinzen
BACKGROUND: Electromechanical discoordination may contribute to long-term pulmonary right ventricular (RV) dysfunction in patients after surgery for congenital heart disease. We sought to evaluate changes in RV function after temporary RV cardiac resynchronization therapy. METHODS AND RESULTS: Twenty-five patients aged median 12.0 years after repair of tetralogy of Fallot and similar lesions were studied echocardiographically (n=23) and by cardiac catheterization (n=5) after primary repair (n=4) or after surgical RV revalvulation for significant pulmonary regurgitation (n=21)...
September 2017: Circulation. Cardiovascular Imaging
https://www.readbyqxmd.com/read/28875729/role-of-cardiac-pacing-in-congenital-complete-heart-block
#17
Stephanie F Chandler, Francis Fynn-Thompson, Douglas Y Mah
Congenital complete heart block affects 1/15,000 live-born infants, predominantly due to atrioventricular nodal injury from maternal antibodies of mothers with systemic lupus erythermatosus or Sjogren's syndrome. The majority of these children will need a pacemaker implanted prior to becoming young adults. This article will review the various patient and technical factors that influence the type of pacemaker implanted, and the current literature on optimal pacing practices. Areas covered: A literature search was performed using PubMed, Embase and Web of Science...
September 6, 2017: Expert Review of Cardiovascular Therapy
https://www.readbyqxmd.com/read/28868038/quantitative-comparison-of-effects-of-dofetilide-sotalol-quinidine-and-verapamil-between-human-ex-vivo-trabeculae-and-in-silico-ventricular-models-incorporating-inter-individual-action-potential-variability
#18
Oliver J Britton, Najah Abi-Gerges, Guy Page, Andre Ghetti, Paul E Miller, Blanca Rodriguez
Background:In silico modeling could soon become a mainstream method of pro-arrhythmic risk assessment in drug development. However, a lack of human-specific data and appropriate modeling techniques has previously prevented quantitative comparison of drug effects between in silico models and recordings from human cardiac preparations. Here, we directly compare changes in repolarization biomarkers caused by dofetilide, dl-sotalol, quinidine, and verapamil, between in silico populations of human ventricular cell models and ex vivo human ventricular trabeculae...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28866284/intracardiac-electrocardiographic-assessment-of-precordial-taser-shocks-in-human-subjects-a-pilot-study
#19
Jason P Stopyra, James E Winslow, David M Fitzgerald, William P Bozeman
BACKGROUND: Case reports of cardiac arrest in temporal proximity to Conducted Electrical Weapon(CEW) exposure raise legitimate concerns about this as a rare possibility. In this pilot study, we respectfully navigate the oversight and regulatory hurdles and demonstrate the intra-shock electrocardiographic effects of an intentional transcardiac CEW discharge using subcutaneous probes placed directly across the precordium of patients with a previously implanted intracardiac EKG sensing lead...
August 24, 2017: Journal of Forensic and Legal Medicine
https://www.readbyqxmd.com/read/28859784/outcomes-of-cardiac-resynchronization-therapy-with-or-without-defibrillation-in-patients-with-nonischemic-cardiomyopathy
#20
MULTICENTER STUDY
Francisco Leyva, Abbasin Zegard, Edmund Acquaye, Christopher Gubran, Robin Taylor, Paul W X Foley, Fraz Umar, Kiran Patel, Jonathan Panting, Howard Marshall, Tian Qiu
BACKGROUND: Recent studies have cast doubt on the benefit of cardiac resynchronization therapy (CRT) with defibrillation (CRT-D) versus pacing (CRT-P) for patients with nonischemic cardiomyopathy (NICM). Left ventricular myocardial scar portends poor clinical outcomes. OBJECTIVES: The aim of this study was to determine whether CRT-D is superior to CRT-P in patients with NICM either with (+) or without (-) left ventricular midwall fibrosis (MWF), detected by cardiac magnetic resonance...
September 5, 2017: Journal of the American College of Cardiology
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