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Atrial fibrillation substrate

Stefan Georg Spitzer, László Károlyi, Carola Rämmler, Frank Scharfe, Thomas Weinmann, Mirko Zieschank, Anke Langbein
INTRODUCTION: A patient-tailored ablation approach focused on the elimination of both pulmonary vein triggers as well as substrate drivers may result in favourable outcomes with recurrent persistent AF patients. OBJECTIVE: We evaluated the long-term outcomes of rotor ablation combined with conventional pulmonary vein isolation (PVI) in patients with recurrent non-paroxysmal AF. METHODS: 58 consecutive patients underwent FIRM-guided rotor ablation followed by conventional PVI for the treatment of recurrent non-paroxysmal AF...
October 21, 2016: Journal of Cardiovascular Electrophysiology
Mu Qin, Xu Liu, Shao-Hui Wu, Xiao-Dong Zhang
Several clinically relevant outcomes post atrial substrate modification in patients with atrial fibrillation (AF) have not been systematically analyzed among published studies on adjunctive cardiac ganglionated plexi (GP) or complex fractionated atrial electograms (CFAE) ablation vs. pulmonary vein isolation (PVI) alone. Out of 176 reports identified, the present meta-analysis included 14 randomized and non-randomized controlled trials (1613 patients) meeting inclusion criteria. Addition of GP ablation to PVI significantly increased freedom from atrial tachyarrhythmia in short- (OR: 1...
2016: PloS One
Christopher P Lawrance, Matthew C Henn, Jacob R Miller, Michael A Kopek, Andrew J Zhang, Richard B Schuessler, Ralph J Damiano
BACKGROUND: Atrial fibrillation (AF) occurs in 30% of patients with mitral regurgitation referred for surgical intervention. However, the underlying mechanisms in this population are poorly understood. This study examined the effects of acute left atrial volume overload on atrial electrophysiology and the inducibility of AF. METHODS: Ten canines underwent insertion of an atrioventricular shunt between the left ventricle and left atrium. Shunt and aortic flows were calculated, and the shunt was titrated to a shunt fraction to 40% to 50% of cardiac output...
October 15, 2016: Annals of Thoracic Surgery
Joshua Xu, Jessica G Y Luc, Kevin Phan
Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia in modern clinical practice, with an estimated prevalence of 1.5-2%. The prevalence of AF is expected to double in the next decades, progressing with age and increasingly becoming a global medical challenge. The first-line treatment for AF is often medical treatment with either rate control or anti-arrhythmic agents for rhythm control, in addition to anti-coagulants such as warfarin for stroke prevention in patient at risk. Catheter ablation has emerged as an alternative for AF treatment, which involves myocardial tissue lesions to disrupt the underlying triggers and substrates for AF...
September 2016: Journal of Thoracic Disease
Martin Huemer, Daniel Qaiyumi, Philipp Attanasio, Abdul Parwani, Burkert Pieske, Florian Blaschke, Leif-Hendrik Boldt, Wilhelm Haverkamp, Alexander Wutzler
AIMS: In persistent atrial fibrillation (AF), left atrial low-voltage areas and complex fractionated atrial electrograms (CFAEs) have been thoroughly discussed as critical substrate points for AF perpetuation. Thus, in patients undergoing pulmonary vein isolation, these sites are often considered additional ablation targets. Currently, mapping techniques for these substrate indicators are still under discussion. The aim of this study was to evaluate the impact of different mapping catheters on the detection of low-voltage areas and CFAE...
October 12, 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
Hoang H Nguyen, Shabana Shahanavaz, George F Van Hare, David T Balzer, Ramzi Nicolas, Jennifer N Avari Silva
BACKGROUND: Percutaneous pulmonary valve implantation (PPVI) is first-line therapy for some congenital heart disease patients with right ventricular outflow tract dysfunction. The hemodynamics improvements after PPVI are well documented, but little is known about its effects on the electrophysiologic substrate. The objective of this study is to assess the short- and medium-term electrophysiologic substrate changes and elucidate postprocedure arrhythmias. METHODS AND RESULTS: A retrospective chart review of patients undergoing PPVI from May 2010 to April 2015 was performed...
September 30, 2016: Journal of the American Heart Association
Anna M May, David R Van Wagoner, Reena Mehra
A surge of data has reproducibly identified strong associations of obstructive sleep apnea (OSA) with cardiac arrhythmias. As an extension of epidemiologic and clinic-based findings, experimental investigations have made strides in advancing our understanding of the putative OSA and cardiac arrhythmogenesis mechanistic underpinnings. While most studies have focused on the links between OSA and atrial fibrillation (AF), relationships with ventricular arrhythmias have also been characterized. Key findings implicate OSA-related autonomic nervous system fluctuations typified by enhanced parasympathetic activation during and sympathetic surges subsequent to respiratory events which contribute to augmented arrhythmic propensity...
September 29, 2016: Chest
Alonso Pedrote, Adolfo Fontenla, Javier García-Fernández
INTRODUCTION AND OBJECTIVES: This report presents the findings of the 2015 Spanish Catheter Ablation Registry. METHODS: For data collection, each center was allowed to choose freely between 2 systems: retrospective, requiring the completion of a standardized questionnaire, and prospective, involving reporting to a central database. RESULTS: Data were collected from 82 centers. A total of 12 863 ablation procedures were performed, for a mean of 157±119 and a median of 138 procedures per center...
September 28, 2016: Revista Española de Cardiología
Liselotte C R Hensen, Victoria Delgado, Suzanne E van Wijngaarden, Melissa Leung, Mihaly K de Bie, Maurits S Buiten, Martin J Schalij, Jos J Van de Kerkhof, Ton J Rabelink, Joris I Rotmans, J Wouter Jukema, Jeroen J Bax
BACKGROUND: The prevalence of atrial fibrillation (AF) in end-stage renal disease (ESRD) patients is relatively high. The present study evaluated the association between left atrial (LA) remodelling, including an increased size and myocardial fibrosis, and slow LA conduction and the occurrence of AF. METHODS: In 171 ESRD patients enrolled in the Implantable Cardioverter Defibrillators in Dialysis patients (ICD2) trial, the LA dimensions, LA conduction delay [as reflected by the time difference between P-wave onset on surface electrocardiogram and A'-wave on tissue Doppler imaging (PA-TDI)] and LA function were compared between patients who exhibited AF versus patients without AF...
September 29, 2016: Nephrology, Dialysis, Transplantation
Rishi Arora, Gary L Aistrup, Stephen Supple, Caleb Frank, Jasleen Singh, Shannon Tai, Anne Zhao, Laura Chicos, William Marszalec, Ang Guo, Long-Sheng Song, J Andrew Wasserstrom
BACKGROUND: The peculiarities of T-tubule morphology and distribution in the atrium - and how they contribute to excitation-contraction coupling - are just beginning to be understood. OBJECTIVE: To determine T-tubule density in the intact, live right and left atria in a large animal and to determine intra-regional differences in T-tubule organization within each atrium. METHODS: Using confocal microscopy, T-tubules were imaged in both atria in intact, Langendorf-perfused normal dog hearts loaded with di-4-ANEPPS...
September 23, 2016: Heart Rhythm: the Official Journal of the Heart Rhythm Society
David Y Chiang, Albert J R Heck, Dobromir Dobrev, Xander H T Wehrens
Reversible phosphorylation of proteins is a delicate yet dynamic balancing act between kinases and phosphatases, the disturbance of which underlies numerous disease processes. While our understanding of protein kinases has grown tremendously over the past decades, relatively little is known regarding protein phosphatases. This may be because protein kinases are great in number and relatively specific in function, and thereby amenable to be studied in isolation, whereas protein phosphatases are much less abundant and more unspecific in their function...
September 20, 2016: Journal of Molecular and Cellular Cardiology
Mrinal Yadava, Michael D Shapiro
Imaging modalities such as computed tomography, magnetic resonance, positron emission tomography, and single-photon emission computed tomography are an indispensable component of cardiac arrhythmia management. Over the last two decades, developments in imaging techniques have facilitated safer and more effective cardiac ablation and device implantation procedures. Pre-procedural assessment of arrhythmogenic substrate and integration with electroanatomic data has significantly impacted the management of atrial fibrillation and ventricular tachycardia...
November 2016: Current Treatment Options in Cardiovascular Medicine
Céline Jumeau, Alain Rupin, Pauline Chieng-Yane, Nathalie Mougenot, Noël Zahr, Monique David-Dufilho, Stéphane N Hatem
The present study tested the hypothesis that thrombin participates in formation of left atrial remodeling and that direct oral anticoagulants, such as direct thrombin inhibitors (DTIs), can prevent its progression. In a rat model of heart failure associated with left atrial dilation, we found that chronic treatment with DTIs reduces the atrial remodeling and the duration of atrial fibrillation (AF) episodes induced by burst pacing by inhibiting myocardial hypertrophy and fibrosis. In addition to the prevention of thromboembolism complicating AF, DTIs may be of interest to slow down the progression of the arrhythmogenic substrate...
August 2016: JACC. Basic to Translational Science
Takehito Sasaki, Kohki Nakamura, Shigeto Naito, Kentaro Minami, Keiko Koyama, Eiji Yamashita, Koji Kumagai, Shigeru Oshima
BACKGROUND: We aimed to identify the predictors of clinical outcomes after circumferential pulmonary vein isolation (CPVI) without any substrate modification for long-standing persistent atrial fibrillation (LSP-AF). METHODS: This study retrospectively analyzed 70 consecutive LSP-AF patients who underwent an initial CPVI and were followed up for more than one year. The right and left atrial volumes indexed to the body surface areas (RAVI and LAVI) were determined by pre-acquired contrast-enhanced computed tomography (CT)...
September 18, 2016: Pacing and Clinical Electrophysiology: PACE
Rohan S Wijesurendra, Alexander Liu, Christian Eichhorn, Rina Ariga, Eylem Levelt, William T Clarke, Christopher T Rodgers, Theodoros D Karamitsos, Yaver Bashir, Matthew Ginks, Kim Rajappan, Tim Betts, Vanessa M Ferreira, Stefan Neubauer, Barbara Casadei
BACKGROUND: Lone atrial fibrillation (AF) may reflect a subclinical cardiomyopathy that persists after sinus rhythm (SR) restoration, providing a substrate for AF recurrence. To test this hypothesis, we investigated the effect of restoring SR by catheter ablation on left ventricular (LV) function and energetics in patients with AF but no significant comorbidities. METHODS: Fifty-three patients with symptomatic paroxysmal or persistent AF and without significant valvular disease, uncontrolled hypertension, coronary artery disease, uncontrolled thyroid disease, systemic inflammatory disease, diabetes mellitus, or obstructive sleep apnea (ie, lone AF) undergoing ablation and 25 matched control subjects in SR were investigated...
October 11, 2016: Circulation
R Talotta, F Atzeni, A Batticciotto, D Ventura, P Sarzi-Puttini
It is still unknown whether there is an association between the use of certolizumab pegol (CZP) in rheumatic patients and the onset of cardiac arrhythmias. We describe the cases of two patients with rheumatoid arthritis (RA) treated with CZP as the first-line biological drug and methotrexate (MTX), who developed an arrhythmic event. The first was a 60-year-old, hypertensive male smoker, the second a 66-year-old dyslipidemic female non-smoker. Both were diagnosed as having RA in 2010, and started treatment with MTX plus CZP...
2016: Reumatismo
Shinsuke Miyazaki, Hiroshi Taniguchi, Shigeki Kusa, Hiroaki Nakamura, Hitoshi Hachiya, Kenzo Hirao, Yoshito Iesaka
BACKGROUND: A paucity of data exists about long-term outcomes after catheter ablation of persistent atrial fibrillation (AF). The mechanisms of AF are still unclear. OBJECTIVE: The purpose of this study was to evaluate the 5-year outcome after persistent AF ablation using sequential defragmentation approaches and to identify the prognostic factors. METHODS: One hundred thirty-five patients with persistent AF (age 62 ± 9 years, 76 longstanding persistent AF) underwent catheter ablation using biatrial linear defragmentation approaches consisting of substrate modification for eliminating AF after pulmonary vein antrum isolation...
August 30, 2016: Heart Rhythm: the Official Journal of the Heart Rhythm Society
Alejandro Liberos, Alfonso Bueno-Orovio, Miguel Rodrigo, Ursula Ravens, Ismael Hernandez-Romero, Francisco Fernandez-Aviles, Maria S Guillem, Blanca Rodriguez, Andreu M Climent
BACKGROUND: Atrial remodeling as a result of long-standing persistent atrial fibrillation (AF) induces substrate modifications that lead to different perpetuation mechanisms than in paroxysmal AF and a reduction in the efficacy of antiarrhythmic treatments. OBJECTIVE: The purpose of this study was to identify the ionic current modifications that could destabilize reentries during chronic AF and serve to personalize antiarrhythmic strategies. METHODS: A population of 173 mathematical models of remodeled human atrial tissue with realistic intersubject variability was developed based on action potential recordings of 149 patients diagnosed with AF...
August 26, 2016: Heart Rhythm: the Official Journal of the Heart Rhythm Society
Tolga Aksu, Tümer Erdem Guler, Kivanc Yalin, Ali Oto
Pulmonary vein isolation has been accepted as potential target for ablation of paroxysmal atrial fibrillation (AF) given that the pulmonary veins are the main source of AF triggers. However, ablation strategies for persistent AF are less well defined. Mapping and ablation of complex fractionated atrial electrograms (CFAEs) is one strategy that has been proposed as a strategy for substrate modification although there is no consensus on their definition and procedural endpoints. Results of clinical studies have been conflicting...
August 26, 2016: Pacing and Clinical Electrophysiology: PACE
Uğur Canpolat, Kudret Aytemir, Tuncay Hazirolan, Necla Özer, Ali Oto
BACKGROUND: Left atrial (LA) fibrosis is known as the hallmark for arrhythmogenic substrate in atrial fibrillation (AF). Quantification of LA fibrosis by using delayed-enhanced magnetic resonance imaging (DE-MRI) in AF patients is a pioneering noninvasive technique. Vitamin D (vitD) negatively regulates the renin-angiotensin system, binds to vitD receptors on cardiac myocytes, and has antioxidant properties that may ameliorate the inflammation and proarrhythmic substrate formation. However, its role in LA fibrosis is unclear...
August 20, 2016: Journal of Cardiology
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