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pace mapping

Kensuke Ihara, Koji Sugiyama, Kentaro Takahashi, Masahiro Yamazoe, Tetsuo Sasano, Tetsushi Furukawa
Recent genome-wide association studies targeting atrial fibrillation (AF) have indicated a strong association between the genotype and electrophysiological phenotype in the atria. That encourages us to utilize a genetically-engineered mouse model to elucidate the mechanism of AF. However, it is difficult to evaluate the electrophysiological properties in murine atria due to their small size. This protocol describes the electrophysiological evaluation of atria using an optical mapping system with a high temporal and spatial resolution in Langendorff perfused murine hearts...
February 22, 2018: Journal of Visualized Experiments: JoVE
Huan Wang, Xiaoru Che
INTRODUCTION: Differentiation of wide QRS complex tachycardia required repeated electrophysiological stimuli and mapping. However, instability of tachycardia would increase the difficulty in differential diagnosis. SYMPTOMS AND CLINICAL FINDINGS: In this paper, we reported a wide QRS tachycardia following ablation of an atrioventricular reentrant tachycardia participated by a poster-septal accessory pathway. Limited differentiation strategy was performed because the wide QRS tachycardia was self-limited and with unstable hemodynamics...
March 2018: Medicine (Baltimore)
Taihei Itoh, Takumi Yamada
INTRODUCTION: Preferential conduction from an origin to breakout sites can occur during ventricular arrhythmias (VAs) originating from the left ventricular papillary muscles (LVPMs). The purpose of this study was to investigate the incidence, electrophysiological characteristics, and relevance to radiofrequency catheter ablation (RFCA) of such a preferential conduction demonstrated by pace mapping. METHODS AND RESULTS: We studied 34 consecutive patients undergoing RFCA of 40 LVPM VAs...
March 14, 2018: Journal of Cardiovascular Electrophysiology
Anthony Li, Joseph Samuel Davis, Alexander Grimster, Jeremiah Wierwille, Keith Herold, Dennis Morgan, Elijah R Behr, Stephen Shorofsky, Magdi Saba
Aims: To determine if a software algorithm can use an individualized distance-morphology difference model, built from three initial pacemaps, to prospectively locate the exit site (ES) of ventricular arrhythmias (VA). Methods and results: Consecutive patients undergoing ablation of VA from a single centre were recruited. During mapping, three initial pacing points were collected in the chamber of interest and the navigation algorithm applied to predict the ES, which was corroborated by conventional mapping techniques...
March 8, 2018: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
Baptiste Maille, Moloy Das, Ahmed Hussein, Matthew Shaw, Vivek Chaturvedi, Maureen Morgan, Christina Ronayne, Richard L Snowdon, Dhiraj Gupta
INTRODUCTION: The ConfiDENSE™ module (Carto3 v4) allows rapid annotation of endocardial electrograms acquired by multi-electrode (ME) mapping. However, its accuracy in assessing atrial voltages is unknown. METHODS AND RESULTS: Two ConfiDENSE™ left atrial voltage maps were created during continuous pacing in 20 patients undergoing catheter ablation for persistent AF using a ME lasso catheter and a Contact Force (CF) sensing ablation catheter. The automated Tissue Proximity indicator (TPI) filter was then applied to the ME map to yield a TPI map...
March 5, 2018: Journal of Cardiovascular Electrophysiology
James H P Gamble, Neil Herring, Matthew R Ginks, Kim Rajappan, Yaver Bashir, Tim R Betts
BACKGROUND: Cardiac Resynchronization Therapy (CRT) is an effective treatment for selected patients with heart failure, but can be limited by the inability to place the left ventricular (LV) lead via the coronary sinus. OBJECTIVE: We have developed an alternative approach, placing the LV lead endocardially via an interventricular septal puncture; this study was designed to assess the feasibility and safety of this technique. METHODS: All patients were anticoagulated with warfarin (INR 2...
March 1, 2018: Heart Rhythm: the Official Journal of the Heart Rhythm Society
Shuanglun Xie, Benoit Desjardins, Maciej Kubala, Jackson Liang, Jiandu Yang, Rob J van der Geest, Robert Schaller, Michael Riley, David Callans, Erica Zado Pac, Francis Marchlinski, Saman Nazarian
BACKGROUND: Criteria for identification of anatomic ventricular tachycardia (VT) substrates in arrhythmogenic right ventricular cardiomyopathy (ARVC) on late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) are unclear. OBJECTIVE: We sought to define a) the association of regional RV epicardial voltage amplitude with the distribution of LGE, and b) appropriate image signal intensity (SI) thresholds for VT substrate identification, in ARVC. METHODS: Pre-procedural LGE-CMR and epicardial electrogram mapping were performed in 10 ARVC patients...
March 1, 2018: Heart Rhythm: the Official Journal of the Heart Rhythm Society
Hongjian Li, Qi Fang, Yijun Ge, Zhong Li, Jianjun Meng, Jianbing Zhu, Hongbo Yu
Simple cells in the cat primary visual cortex usually have elongated receptive fields (RFs), and their orientation selectivity can be largely predicted by their RFs. As to the relay cells in cats' lateral geniculate nucleus (LGN), they also have weak but significant orientation bias. It is thus of interest to investigate the fine spatiotemporal receptive field (STRF) properties in LGN, compare them with the dynamics of orientation tuning, and examine the dynamic relationship between STRF and orientation sensitivity in LGN...
February 23, 2018: Neuroscience
J Fedida, T Strisciuglio, M Sohal, M Wolf, K Van Beeumen, A Neyrinck, P Taghji, C Lepiece, A Almorad, Y Vandekerckhove, R Tavernier, M Duytschaever, S Knecht
PURPOSE: Catheter ablation is an effective treatment for premature ventricular complexes (PVCs). Activation mapping is accurate but requires PVCs at the time of the ablation. Pace-mapping correlation (PMC) is a supplemental tool recently developed as an integrated module for an electro-anatomical mapping platform. Our study sought to investigate whether pace-mapping technology provides similar ablation results in patients with low versus high idiopathic PVC burden at the time of ablation and the relationship between sites with the highest PMC and the earliest local activation time (LAT)...
February 24, 2018: Journal of Interventional Cardiac Electrophysiology: An International Journal of Arrhythmias and Pacing
Laura R Bear, Peter R Huntjens, Richard Walton, Olivier Bernus, Ruben Coronel, Rémi Dubois
BACKGROUND: Poor identification of electrical dyssynchrony is postulated to be a major factor contributing to the low success rate for cardiac resynchronization therapy (CRT). OBJECTIVE: To evaluate body surface mapping and electrocardiographic imaging (ECGi) to detect electrical dyssynchrony noninvasively. METHODS: Langendorff-perfused pig hearts (n=11) were suspended in a human torso-shaped tank, with LBBB induced through ablation. Recordings were taken simultaneously from a 108-electrode epicardial sock and 128 electrodes embedded in the tank surface during sinus rhythm and ventricular pacing...
February 22, 2018: Heart Rhythm: the Official Journal of the Heart Rhythm Society
Jun-Ichi Okada, Takumi Washio, Machiko Nakagawa, Masahiro Watanabe, Yoshimasa Kadooka, Taro Kariya, Hiroshi Yamashita, Yoko Yamada, Shin-Ichi Momomura, Ryozo Nagai, Toshiaki Hisada, Seiryo Sugiura
Background: Cardiac resynchronization therapy is an effective device therapy for heart failure patients with conduction block. However, a problem with this invasive technique is the nearly 30% of non-responders. A number of studies have reported a functional line of block of cardiac excitation propagation in responders. However, this can only be detected using non-contact endocardial mapping. Further, although the line of block is considered a sign of responders to therapy, the mechanism remains unclear. Methods: Herein, we created two patient-specific heart models with conduction block and simulated the propagation of excitation based on a cellmodel of electrophysiology...
2018: Frontiers in Physiology
Andrew Stirling, Josie Coburn
The purpose of this essay is to critically review the design of methods for ethically robust forms of technology appraisal in the regulation of research and innovation in synthetic biology. It will focus, in particular, on the extent to which cost-benefit analysis offers a basis for informing decisions about which technological pathways to pursue and which to discourage. A further goal is to consider what (if anything) the precautionary principle might offer in enabling better decisions. And this, in turn, raises questions about why mention of precaution can excite accusations of unscientific bias or irrational, "anti-innovation" extremism...
January 2018: Hastings Center Report
James Winter, Martin J Bishop, Catherine D E Wilder, Christopher O'Shea, Davor Pavlovic, Michael J Shattock
Rationale: Arrhythmogenic cardiac alternans are thought to be an important determinant for the initiation of ventricular fibrillation. There is limited information on the effects of sympathetic nerve stimulation (SNS) on alternans in the intact heart and the conclusions of existing studies, focused on investigating electrical alternans, are conflicted. Meanwhile, several lines of evidence implicate instabilities in Ca handling, not electrical restitution, as the primary mechanism underpinning alternans. Despite this, there have been no studies on Ca alternans and SNS in the intact heart...
2018: Frontiers in Physiology
Michael Ghannam, Hubert Cochet, Pierre Jais, Maxime Sermesant, Smita Patel, Konstantinos C Siontis, Fred Morady, Frank Bogun
BACKGROUND: Myocardial wall thickness (WT) in patients with a prior myocardial infarction has been used to indicate scarring. However, the correlation of WT with sites critical to ventricular tachycardia (VT) has not been previously investigated. The purpose of this study was to correlate electroanatomic mapping data obtained during VT ablation with WT determined by cardiac computed tomography (CT). METHODS AND RESULTS: Cardiac CTs were performed in 15 consecutive patients (mean age 63±10 years, 86% male, left ventricular ejection fraction 27±12%) with a prior infarct referred for VT ablation...
January 30, 2018: Journal of Cardiovascular Electrophysiology
S Honarbakhsh, R J Hunter, G Dhillon, W Ullah, E Keating, R Providencia, A Chow, M J Earley, R J Schilling
INTRODUCTION: This study sought to validate a novel wavefront mapping system utilizing whole-chamber basket catheters (CARTOFINDER, Biosense Webster). The system was validated in terms of (1) mapping atrial-paced beats and (2) mapping complex wavefront patterns in atrial tachycardia (AT). METHODS AND RESULTS: Patients undergoing catheter ablation for AT and persistent AF were included. A 64-pole-basket catheter was used to acquire unipolar signals that were processed by CARTOFINDER mapping system to generate dynamic wavefront propagation maps...
January 24, 2018: Journal of Cardiovascular Electrophysiology
Kanchan Kulkarni, Steven W Lee, Ryan Kluck, Elena G Tolkacheva
Cardiac alternans, a beat-to-beat alternation in action potential duration (APD), can lead to fatal arrhythmias. During periodic pacing, changes in diastolic interval (DI) depend on subsequent changes in APD, thus enhancing cardiac instabilities through a 'feedback' mechanism. Recently, an anti-arrhythmic Constant DI pacing protocol was proposed and shown to be effective in suppressing alternans in 0D and 1D in silico studies. However, previous experimental validation of Constant DI pacing in the heart has been unsuccessful due to the spatio-temporal complexity of 2D cardiac tissue and the technical challenges in its real-time implementation...
January 22, 2018: Annals of Biomedical Engineering
O Kittnar, L Riedlbauchová, J Tomis, M LoŽek, A Valeriánová, M Hrachovina, M Mlček, M Huptych, J Janoušek, L Lhotská
Cardiac resynchronization therapy (CRT) has proven efficacious in reducing or even eliminating cardiac dyssynchrony and thus improving heart failure symptoms. However, quantification of mechanical dyssynchrony is still difficult and identification of CRT candidates is currently based just on the morphology and width of the QRS complex. As standard 12-lead ECG brings only limited information about the pattern of ventricular activation, we aimed to study changes produced by different pacing modes on the body surface potential maps (BSPM)...
December 30, 2017: Physiological Research
Grzegorz Suwalski, Robert Emery, Jakub Mróz, Kamil Kaczejko, Leszek Gryszko, Andrzej Cwetsch, Andrzej Skrobowski
OBJECTIVES: In patients referred to off-pump coronary artery bypass grafting, pulmonary vein isolation (PVI) may be used for those with persistent atrial fibrillation (AF), an alternative to the Maze procedure. However, the success rate of PVI in persistent AF is limited. The study assesses the prognostic value of focal epicardial electrocardiography of the pulmonary veins (PVs) for surgical ablation results. METHODS: We mapped 140 PV in 35 cases undergoing off-pump coronary artery bypass grafting...
January 15, 2018: Interactive Cardiovascular and Thoracic Surgery
Vishal Luther, Norman Qureshi, Phang Boon Lim, Michael Koa-Wing, Shahnaz Jamil-Copley, Fu Siong Ng, Zachary Whinnett, D Wyn Davies, Nicholas S Peters, Prapa Kanagaratnam, Nick Linton
BACKGROUND: Post ablation reentrant ATs depend upon conducting isthmuses bordered by scar. Bipolar voltage maps highlight scar as sites of low voltage, but the voltage amplitude of an electrogram depends upon the myocardial activation sequence. Furthermore, a voltage threshold that defines atrial scar is unknown. We used Ripple Mapping (RM) to test whether these isthmuses were anatomically fixed between different activation vectors and atrial rates. METHODS: We studied post-AF ablation ATs where > 1 rhythm was mapped...
January 17, 2018: Journal of Cardiovascular Electrophysiology
Vrishti M Phadumdeo, Seth H Weinberg
Heart rate continuously varies due to autonomic regulation, stochasticity in pacemaking, and circadian rhythm, collectively termed heart rate variability (HRV), during normal physiological conditions. Low HRV is clinically associated with an elevated risk of cardiac arrhythmias. Alternans, a beat-to-beat alternation in action potential duration (APD) and/or intracellular calcium (Ca) transient, is a well-known risk factor associated with cardiac arrhythmias that is typically studied under conditions of a constant pacing rate, i...
January 11, 2018: Journal of Theoretical Biology
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