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https://www.readbyqxmd.com/read/28339750/downstream-overdrive-pacing-and-intracardiac-concealed-fusion-to-guide-rapid-identification-of-atrial-tachycardia-after-atrial-fibrillation-ablation
#1
Chirag R Barbhaiya, Samuel H Baldinger, Saurabh Kumar, Jason S Chinitz, Alan D Enriquez, Roy John, William G Stevenson, Gregory F Michaud
Aims: Atrial tachycardia (AT) related to atrial fibrillation (AF) ablation frequently poses a diagnostic challenge. Downstream overdrive pacing (DOP) can be used to rapidly detect reentry and assess proximity of a pacing site to an AT circuit or focus. We hypothesized that systematic DOP using multielectrode catheters would facilitate AT mapping. Methods and results: DOP identified constant fusion when the post-pacing interval (PPI)-tachycardia cycle length (TCL) <40 ms and stimulus to adjacent upstream atrial electrogram interval >75% of TCL...
February 17, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28324970/development-of-data-acquisition-components-for-simultaneous-recording-of-3d-epicardial-and-surface-ecg-signals-in-the-langendorff-perfusion-apparatus
#2
Ryan Wade Selby, Anup Jonchhe, Chen Kaplan, Coeli M Lopes, Behnaz Ghoraani
Sudden Cardiac Death (SCD) claims 7 million lives per year. The importance of myocardial electrogram (EGM) repolarization alternans and surface electrocardiogram (ECG) T-wave alternans is gaining traction for understanding the underlying SCD mechanisms. However, the relationship between the 3D spatial distribution of myocardial EGMs and surface ECG with respect to SCD has yet to be investigated. To make this happen, a modified data acquisition system has been developed and fabricated in conjunction with the Langendorff perfusion system to enable simultaneous recording and analysis of the 3D spatial distribution of myocardial EGMs and the surface ECG...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28318665/the-relation-between-local-repolarization-and-t-wave-morphology-in-heart-failure-patients
#3
Francesco Maffessanti, Joris Wanten, Mark Potse, Francois Regoli, Maria Luce Caputo, Giulio Conte, Daniel Sürder, Annekatrin Illner, Rolf Krause, Tiziano Moccetti, Angelo Auricchio, Frits W Prinzen
BACKGROUND: Both duration and morphology of the T-wave are regarded important parameters describing repolarization of the ventricles. Conventionally, T-wave concordance is explained by an inverse relation between the time of depolarization (TD) and repolarization (TR). Little is known about T-wave morphology and TD-TR relations in patients with heart failure. METHODS: Electro-anatomic maps were obtained in the left (LV) and right ventricle (RV) and in the coronary sinus (CS) in patients with heart failure with narrow (nQRS, n=8) and wide QRS complex with (LBBB, n=15) and without left bundle branch block (non-LBBB, n=7)...
February 22, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28316148/ablation-of-complex-fractionated-electrograms-with-or-without-additional-linear-lesions-for-persistent-atrial-fibrillation-the-adline-trial
#4
Sonia Ammar-Busch, Felix Bourier, Tilko Reents, Verena Semmler, Marta Telishevska, Susanne Kathan, Monika Hofmann, Gabriele Hessling, Isabel Deisenhofer
BACKGROUND: For persistent atrial fibrillation (AF) ablation, different strategies including complex fractionated atrial electrograms (CFAE) ablation and linear lesions (LL) have been used in addition to pulmonary vein isolation (PVI). However, it is still a matter of debate if extended substrate modification improves long-term outcome. The aim of this study was to determine the benefit of LL in addition to PVI and CFAE ablation regarding freedom from arrhythmia recurrence in patients with persistent AF...
March 18, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28314845/distribution-and-prognostic-significance-of-fragmented-qrs-in-patients-with-brugada-syndrome
#5
Hiroshi Morita, Atsuyuki Watanabe, Yoshimasa Morimoto, Satoshi Kawada, Motomi Tachibana, Koji Nakagawa, Nobuhiro Nishii, Hiroshi Ito
BACKGROUND: Fragmented QRS complexes (fQRS) in the right precordial leads are associated with occurrence of ventricular fibrillation (VF) in Brugada syndrome. Recently, epicardial mapping has revealed abnormal electrograms at the right ventricular (RV) outflow tract and inferior region of the right ventricle. fQRS may reflect the extent of the area of abnormal potentials, but whether the distribution of fQRS has prognostic value is not known. METHODS AND RESULTS: We evaluated the existence of fQRS in 456 patients with Brugada syndrome, including 117 patients with syncope and 23 patients with VF...
March 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/28298182/electrocardiogram-his-bundle-potentials-can-be-recorded-noninvasively-beat-by-beat-on-surface-electrocardiogram
#6
Gaopin Wang, Renguang Liu, Qinghua Chang, Zhaolong Xu, Yingjie Zhang, Dianzhu Pan
BACKGROUND: The micro waveform of His bundle potential can't be recorded beat-to-beat on surface electrocardiogram yet. We have found that the micro-wavelets before QRS complex may be related to atrioventricular conduction system potentials. This study is to explore the possibility of His bundle potential can be noninvasively recorded on surface electrocardiogram. METHODS: We randomized 65 patients undergoing radiofrequency catheter ablation of paroxysmal superventricular tachycardia (exclude overt Wolff-Parkinson-White syndrome) to receive "conventional electrocardiogram" and "new electrocardiogram" before the procedure...
March 15, 2017: BMC Cardiovascular Disorders
https://www.readbyqxmd.com/read/28291831/t-wave-loop-area-from-a-pre-implant-12-lead-ecg-is-associated-with-appropriate-icd-shocks
#7
Joachim Seegers, Katerina Hnatkova, Tim Friede, Marek Malik, Markus Zabel
AIMS: In implantable cardioverter-defibrillator (ICD) patients, predictors of ICD shocks and mortality are needed to improve patient selection. Electrocardiographic (ECG) markers are simple to obtain and have been demonstrated to predict mortality. We aimed to assess the association of T-wave loop area and circularity with ICD shocks. METHODS: The study investigated patients with ICDs implanted between 1998 and 2010 for whom digital 12-lead ECGs (Schiller CS200 ECG-Network) of sufficient quality were obtained within 1 month prior to the implantation...
2017: PloS One
https://www.readbyqxmd.com/read/28282453/the-use-of-a-novel-signal-analysis-to-identify-the-origin-of-idiopathic-right-ventricular-outflow-tract-ventricular-tachycardia-during-sinus-rhythm-simultaneous-amplitude-frequency-electrogram-transformation-mapping
#8
Abigail Louise D Te, Satoshi Higa, Fa-Po Chung, Chin-Yu Lin, Men-Tzung Lo, Che-An Liu, Chen Lin, Yi-Chung Chang, Shih-Lin Chang, Li-Wei Lo, Yu-Feng Hu, Ta-Chuan Tuan, Tze-Fan Chao, Jonan Liao, Yao-Ting Chang, Chung-Hsing Lin, Yuan Hung, Shinya Yamada, Kuo-Li Pan, Yenn-Jiang Lin, Shih-Ann Chen
INTRODUCTION: The signal characteristics of intracardiac bipolar electrograms at the origin of idiopathic RVOT-VT during sinus rhythm remain unclear. OBJECTIVE: The study sought to develop a novel real-time/online technique, simultaneous amplitude frequency electrogram transformation (SAFE-T), to quantify and localize the diseased ventricular substrate in idiopathic RVOT-VT. METHODS: We retrospectively investigated the intracardiac bipolar recordings in 70 consecutive patients (26% male, mean age 42±12 years) who underwent successful radiofrequency catheter ablation of idiopathic RVOT-VT...
2017: PloS One
https://www.readbyqxmd.com/read/28269068/identification-and-annotation-of-multiple-periodic-pulse-trains-using-dominant-frequency-and-graph-search-applications-in-atrial-fibrillation-rotor-detection
#9
Rupin Dalvi, Adrian Suszko, Vijay S Chauhan
Biological signals, such as intracardiac electrograms during atrial fibrillation (AF), can contain multiple periodic components or peaks. We propose a method for identifying individual periodic peak trains in signals containing multiple such periodic sequences. We use dominant frequency-based periodicity detection along with a graph search algorithm to identify the most dominant periodic activation set or peaks of interest. We then remove these peaks and iterate until all periodic sequences are identified. The proposed method is tested on simulated AF intra-cardiac electrograms with periodic activation trains of three distinct frequencies corrupted by noise and complex aperiodic signal features...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28269065/development-of-matlab-software-to-control-data-acquisition-from-a-multichannel-systems-multi-electrode-array
#10
Erik Messier
A Multichannel Systems (MCS) microelectrode array data acquisition (DAQ) unit is used to collect multichannel electrograms (EGM) from a Langendorff perfused rabbit heart system to study sudden cardiac death (SCD). MCS provides software through which data being processed by the DAQ unit can be displayed and saved, but this software's combined utility with MATLAB is not very effective. MCSs software stores recorded EGM data in a MathCad (MCD) format, which is then converted to a text file format. These text files are very large, and it is therefore very time consuming to import the EGM data into MATLAB for real-time analysis...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28269048/an-algorithm-for-rotor-tracking-in-atrial-fibrillation-using-graph-search-based-periodic-peak-detection
#11
Rupin Dalvi, Adrian Suszko, Vijay S Chauhan
Rotors are rotating electrical waves that may sustain atrial fibrillation (AF); thereby providing therapeutic targets for catheter ablation. We propose a method for identifying rotors from circular catheter recordings of bipolar intracardiac electrograms (EGM) during AF. We use dominant frequency-based periodicity detection along with a graph search algorithm to identify the most dominant periodic activations or peaks of interest in each bipolar EGM recorded by a multipolar circular catheter. We then track the activations across catheter bipoles to determine whether they conform to the rotational pattern of a rotor...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268890/amplitude-based-beat-detection-for-atrial-fibrillation-in-pacemaker
#12
Seung Hwan Lee, Hyoun Seok Myoung, Chang Hoon Kang, Eue Keun Choi, Kyoung Joung Lee
Bradycardia is defined as a sinus rhythm of less than 60 beats per minute and atrial tachyarrhythmia including atrial fibrillation (AF) is frequently associated with bradycardia. Pacemaker is the only effective treatment for symptomatic bradycardia and automatic mode switching (AMS) function is built in pacemaker to switch mode in the presence of atrial tachyarrhythmia. AMS algorithms consider appropriate mode switching in case of undersensing or oversensing and this consideration makes their onset time and resynchronization time late...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268887/maximum-likelihood-cardiac-conduction-velocity-estimation-from-sequential-mapping-in-the-presence-of-activation-time-noise-with-unknown-variances
#13
Mohammad Hassan Shariat, Saeed Gazor, Damian Redfearn
The cardiac conduction velocity (CV) can be estimated by analysing the activation times (ATs) and the locations of the electrodes that are used for the intracardiac electrogram (IEGM) recording. Here, we study the problem of the CV estimation in sequential mapping without using any independent electrogram as a time alignment reference. We assume that the IEGMs are sequentially recorded from several sites, where at each site, at least two of the catheter's electrodes are in contact with the cardiac tissue. We consider the planar wavefront with stable CV that propagates within the recording sites throughout our data collection period...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268886/catheter-simulator-software-tool-to-generate-electrograms-of-any-multi-polar-diagnostic-catheter-from-3d-atrial-tissue
#14
Kristina E Shillieto, Prasanth Ganesan, Anthony J Salmin, Elizabeth M Cherry, Arkady M Pertsov, Behnaz Ghoraani
Simulations are excellent tools for assessing new therapeutic strategies and are often conducted before implementing new therapy options in a clinical practice. For patients suffering from a heart arrhythmia, the main source of information comes from an intracardiac catheter. One of the common catheters is a Lasso multi-pole diagnostic catheter, which is a catheter that has 20 electrodes in a circular pattern. In this paper, we developed algorithm and simulation software that allows the users to place a multi-pole catheter on the atrial endocardial surface and record electrograms...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268381/cardiac-conduction-velocity-estimation-from-sequential-mapping-assuming-known-gaussian-distribution-for-activation-time-estimation-error
#15
Mohammad Hassan Shariat, Saeed Gazor, Damian Redfearn
In this paper, we study the problem of the cardiac conduction velocity (CCV) estimation for the sequential intracardiac mapping. We assume that the intracardiac electrograms of several cardiac sites are sequentially recorded, their activation times (ATs) are extracted, and the corresponding wavefronts are specified. The locations of the mapping catheter's electrodes and the ATs of the wavefronts are used here for the CCV estimation. We assume that the extracted ATs include some estimation errors, which we model with zero-mean white Gaussian noise values with known variances...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268380/a-novel-catheter-guidance-algorithm-for-localization-of-atrial-fibrillation-rotor-and-focal-sources
#16
Anthony J Salmin, Prasanth Ganesan, Kristina E Shillieto, Elizabeth M Cherry, David T Huang, Arkady M Pertsov, Behnaz Ghoraani
Locating atrial fibrillation (AF) focal and rotor sources can help improve target ablation therapy for AF. However, it remains unclear how to use the information provided by multi-polar diagnostic catheters (MPDC) to locate AF sources. Our aim was to develop a catheter-guidance algorithm to locate AF focal and rotor sources using a conventional MPDC. We simulated a 10 cm × 10 cm atrial tissue with focal and rotor sources using the Nygren et al. ionic model. We modeled a Lasso MPDC with 20-unipole electrodes placed with a spacing of 4...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268379/kurtosis-as-a-statistical-approach-to-identify-the-pivot-point-of-the-rotor
#17
Shivaram P Arunachalam, Elizabeth M Annoni, Siva K Mulpuru, Paul A Friedman, Elena G Tolkacheva
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia that causes stroke affecting more than 2.3 million people in the US. Catheter ablation to terminate AF is successful for paroxysmal AF but suffers limitations with persistent AF patients as current mapping methods cannot identify AF active substrates outside of pulmonary vein region. In this work, we developed a novel Kurtosis based mapping technique that can accurately identify pivot points of the rotors that were induced in ex-vivo isolated rabbit heart...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268378/development-of-a-novel-probabilistic-algorithm-for-localization-of-rotors-during-atrial-fibrillation
#18
Prasanth Ganesan, Anthony Salmin, Elizabeth M Cherry, Behnaz Ghoraani
Atrial fibrillation (AF) is an irregular heart rhythm that can lead to stroke and other heart-related complications. Catheter ablation has been commonly used to destroy triggering sources of AF in the atria and consequently terminate the arrhythmia. However, efficient and accurate localization of the AF sustaining sources known as rotors is a major challenge in catheter ablation. In this paper, we developed a novel probabilistic algorithm that can adaptively guide a Lasso diagnostic catheter to locate the center of a rotor...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268303/effects-and-underlying-mechanisms-of-refractory-period-pacing-on-repolarization-dynamics-in-the-human-heart
#19
Diogo Santos, Michele Orini, Xin Zhou, Alfonso Bueno-Orovio, Ben Hanson, Peter Taggart, Martin Hayward, Blanca Rodriguez, Pier Lambiase
Repolarization alternans is related to the initiation of life threatening cardiac arrhythmias. Experimental and computational studies suggest that the abolishment of alternans using dynamic pacing protocols may prevent abnormal heart rhythms. In a recent animal study, refractory period pacing (RPP) on every other beat has shown promising results in alternans reduction. However, the cellular mechanisms underlying this therapy and its efficiency in human patients remain unclear. In this study, in vivo unipolar electrograms acquired during RPP from 240 epicardial sites from one patient were analysed...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28256178/adjunctive-ablation-strategies-improve-the-efficacy-of-pulmonary-vein-isolation-in-non-paroxysmal-atrial-fibrillation-a-systematic-review-and-meta-analysis
#20
REVIEW
Muhammad R Afzal, Anweshan Samanta, Jawaria Chatta, Brihh Ansari, Sam Atherton, Syed Sabzwari, Mohit Turagam, Dhanunjaya Lakkireddy, Mahmoud Houmsse
BACKGROUND: Pulmonary vein (PV) isolation (PVI) has suboptimal outcomes in patients with non-paroxysmal atrial fibrillation (AF). Adjunctive strategies employed to ablate non-PV triggers have shown favorable outcomes. AIMS: To delineate the incremental benefit of adjunctive ablation in patients with non-paroxysmal AF through a meta-analysis. METHODS AND RESULTS: Database searches through August 2016 identified five non-randomized and seven randomized controlled trials (enrolling 1694 patients)...
March 2017: Expert Review of Cardiovascular Therapy
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