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Distribution by Scientific Domains


Selected Abstracts


Automatic 3D Mapping of Complex Fractionated Atrial Electrograms (CFAE) in Patients with Paroxysmal and Persistent Atrial Fibrillation

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2008
JINJIN WU M.D.
Background: Complex fractionated atrial electrograms (CFAE) are a possible target for atrial fibrillation (AF) ablation and can be visualized in three-dimensional (3D) mapping systems with specialized software. Objective: To use the new CFAE software of CartoXP® (Biosense Webster, Diamond Bar, CA, USA) for analysis of spatial distribution of CFAE in paroxysmal and persistent AF. Methods: We included 16 consecutive patients (6 females; mean 59.3 years) with AF (6 paroxysmal and 10 persistent) undergoing AF ablation. Carto maps of left atrium (LA) were reconstructed. Using the new CFAE software, the degree of local electrogram fractionation was displayed color-coded on the map surface. LA was divided into four regions: anterior wall, inferior wall, septum, and pulmonary veins (PV). The relationship among regions with CFAE visualized and CFAE ablation regions (persistent AF only) was analyzed retrospectively. Results: In paroxysmal and persistent AF, CFAE were observed in all four LA regions. In paroxysmal AF, the density of CFAE around the PV was significantly higher than in other regions (P < 0.05) and higher than in persistent AF (P < 0.05). In persistent AF, CFAE were evenly distributed all over the LA. Of 40 effective ablation sites with significant AF cycle length prolongation, 33 (82.5%) were judged retrospectively by CFAE map as CFAE sites. Conclusion: CFAE software can visualize the spatial distribution of CFAE in AF. CFAE in persistent AF were observed in more regions of LA compared to paroxysmal AF in which CFAE concentrated on the PV. Automatically detected CFAE match well with ablation sites targeted by operators. [source]


Initial Experience in the Use of Integrated Electroanatomic Mapping with Three-Dimensional MR/CT Images to Guide Catheter Ablation of Atrial Fibrillation

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2006
JUN DONG M.D.
Introduction: No prior studies have reported the use of integrated electroanatomic mapping with preacquired magnetic resonance/computed tomographic (MR/CT) images to guide catheter ablation of atrial fibrillation (AF) in a series of patients. Methods and Results: Sixteen consecutive patients with drug-refractory AF underwent catheter ablation under the guidance of a three-dimensional (3D) electroanatomic mapping system (Carto, Biosense Webster, Inc., Diamond Bar, CA, USA). Gadolinium-enhanced MR (n = 8) or contrast-enhanced high-resolution CT (n = 8) imaging was performed within 1 day prior to the ablation procedures. Using a novel software package (CartoMerge, Biosense Webster, Inc.), the left atrium (LA) with pulmonary veins (PVs) was segmented and extracted for image registration. The segmented 3D MR/CT LA reconstruction was accurately registered to the real-time mapping space with a combination of landmark registration and surface registration. The registered 3D MR/CT LA reconstruction was successfully used to guide deployment of RF applications encircling the PVs. Upon completion of the circumferential lesions around the PVs, 32% of the PVs were electrically isolated. Guided by a circular mapping catheter, the remaining PVs were disconnected from the LA using a segmental approach. The distance between the surface of the registered 3D MR/CT LA reconstruction and multiple electroanatomic map points was 3.05 ± 0.41 mm. No complications were observed. Conclusions: Three-dimensional MR/CT images can be successfully extracted and registered to anatomically guided clinical AF ablations. The display of detailed and accurate anatomic information during the procedure enables tailored RF ablation to individual PV and LA anatomy. [source]


Mechanisms of Right Atrial Tachycardia Occurring Late After Surgical Closure of Atrial Septal Defects

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2005
ISABELLE MAGNIN-POULL M.D.
Introduction: In patients without structural heart disease, the most frequently occurring AT is the common atrial flutter. In patients with repaired congenital heart disease other mechanisms of AT may occur, due to the presence of an atriotomy that can provide a substrate for reentry. The aim of the present study was to identify the mechanisms of atrial tachycardia (AT) occurring late after atrial septum defect (ASD) repair, with the help of a three-dimensional electroanatomical mapping system. Methods and Results: Twenty-two consecutive patients presenting with AT underwent complete electroanatomic mapping (CARTO®, Biosense Webster, Diamond Bar, CA) of spontaneously occurring and inducible right ATs. Complete maps of 26 ATs were obtained. Three tachycardia mechanisms were identified: single-loop macroreentrant atrial tachycardia (MAT) (n = 7), double-loop MAT (n = 18), and focal AT (n = 1). In all MATs, protected isthmuses were identified as the electrophysiological substrate of the arrhythmia, most frequently the cavotricuspid isthmus (CTI) (n = 24), and a gap between the inferior vena cava and a line of double potentials (n = 11). A mean number of 13.5 ± 2.1 radiofrequency applications were delivered to transect these critical parts of the circuit. During a follow-up of 25 ± 16 months the RF ablation was acutely successful in all patients. Thirteen patients (59%) had an early recurrence of MAT and needed an additional ablation procedure. One of those patients needed two additional ablation procedures. Conclusions: Three-dimensional electroanatomic mapping is useful to identify postsurgical AT mechanisms; the CTI isthmus is involved in 92% MAT, and if the right atrial free wall (RAFW) abnormal tissue related to surgical scar is present this substrate contributes to the MAT circuit [source]


Catheter Ablation for Paroxysmal Atrial Fibrillation: A Randomized Comparison between Multielectrode Catheter and Point-by-Point Ablation

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2010
ALAN BULAVA M.D., Ph.D.
Introduction:,Catheter ablation for paroxysmal atrial fibrillation is widely used for patients with drug-refractory paroxysms of arrhythmia. Recently, novel technologies have been introduced to the market that aim to simplify and shorten the procedure. Aim:,To compare the clinical outcome of pulmonary vein (PV) isolation using a multipolar circular ablation catheter (PVAC group), with point-by-point PV isolation using an irrigated-tip ablation catheter and the CARTO mapping system (CARTO group; CARTO, Biosense Webster, Diamond Bar, CA, USA). Methods:,Patients with documented PAF were randomized to undergo PV isolation using PVAC or CARTO. Atrial fibrillation (AF) recurrences were documented by serial 7-day Holter monitoring. Results:,One hundred and two patients (mean age 58 ± 11 years, 68 men) were included in the study. The patients had comparable baseline clinical characteristics, including left atrial dimensions and left ventricular ejection fraction, in both study arms (PVAC: n = 51 and CARTO: n = 51). Total procedural and fluoroscopic times were significantly shorter in the PVAC group (107 ± 31 minutes vs 208 ± 46 minutes, P < 0.0001 and 16 ± 5 minutes vs 28 ± 8 minutes, P < 0.0001, respectively). The AF recurrence was documented in 23% and 29% of patients in the PVAC and CARTO groups, respectively (P = 0.8), during the mean follow-up of 200 ± 13 days. No serious complications were noted in both study groups. Conclusions:,Clinical success rates of PV isolation are similar when using multipolar circular PV ablation catheter and point-by-point ablation with a three-dimensional (3D) navigation system in patients with PAF, and results in shorter procedural and fluoroscopic times with a comparable safety profile. (PACE 2010; 33:1039,1046) [source]


Real-time Integration of Intracardiac Echocardiography and Electroanatomic Mapping in PVCs Arising from the LV Anterior Papillary Muscle

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2009
Ph.D., TAKUMI YAMADA M.D.
A 54-year-old woman with idiopathic premature ventricular contractions (PVCs) underwent electrophysiological testing. Three-dimensional (3D) geometries of the papillary muscles and chamber of the left ventricle (LV) were reconstructed using a CARTO-based 3D ultrasound imaging system (Biosense Webster Inc., Diamond Bar, CA, USA) during the PVCs. Activation mapping in the LV was then performed during the PVCs and the activation map revealed the earliest ventricular activation on the anterior papillary muscle. An irrigated radiofrequency current delivered at that site with guidance from that system eliminated the PVCs. This case may suggest that the guidance system may be feasible and useful for catheter ablation of PVCs arising from uncommon sites. [source]


Role of Left Ventricular Scar and Purkinje-Like Potentials During Mapping and Ablation of Ventricular Fibrillation in Dilated Cardiomyopathy

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2009
ANIL-MARTIN SINHA M.D., D.Phil.
Background: Purkinje-like potentials (PLPs) have been described as important contributors to initiation of ventricular fibrillation (VF) in patients with normal hearts, ischemic cardiomyopathy, and early after-myocardial infarction. Methods: Of the 11 consecutive patients with VF storm, nonischemic cardiomyopathy (68 ± 22 years, left ventricular ejection fraction 28 ± 8%) who were given antiarrhythmic drugs and/or heart failure management, five had recurrent VF and underwent electrophysiology study (EPS) and catheter ablation. Results: At EPS, frequent monomorphic premature ventricular contractions (PVC) and/or ventricular tachycardia did not occur. With isoproterenol, VF was induced in three patients, and sustained monomorphic PVCs were induced in one patient. Three-dimensional electroanatomical mapping using CARTO (Biosense-Webster Inc., Diamond Bar, CA) revealed posterior wall scar in four of the five patients. PLP in sinus rhythm were recorded around the scar border in these four patients, and radiofrequency ablation targeting PLP was successfully performed at these sites. The patient without PLP did not undergo ablation. During follow-up (12 ± 5 months), only the patient without PLP had four VF recurrences requiring implantable cardioverter-defibrillator (ICD) shocks. Conclusion: In patients with VF and dilated cardiomyopathy, left ventricular posterior wall scar in the vicinity of the mitral annulus seems to be a common finding. Targeting PLP along the scar border zone for ablation seems to efficiently prevent VF recurrence in these patients. [source]


Acute and Chronic Pulmonary Vein Reconnection after Atrial Fibrillation Ablation: A Prospective Characterization of Anatomical Sites

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2008
KIM RAJAPPAN M.D.
Background:Arrhythmia recurrence after atrial fibrillation (AF) ablation is often associated with pulmonary vein reconnection (PVR). We prospectively examined anatomical sites of both acute and chronic PVR. Methods:One hundred and fifty AF patients underwent PV wide encirclement and sites where immediate electrical isolation (EI) occurred were tagged using electroanatomic mapping/CT integration (CartomergeÔ, Biosense Webster, Diamond Bar, CA, USA). After 30 minutes PVs were checked and acute PVR sites marked at reisolation. Chronic PVR sites were marked at the time of repeat procedures. Results:On the left, immediate EI sites were predominantly on the intervenous ridge (IVR) and PV-left atrial appendage (PV-LAA) ridge. On the right they were at the roof, IVR, and floor of the PVs. Ninety-eight of one hundred and fifty patients had PVs checked after >30 minutes. Thirty-two of ninety-eight had acute PVR. This was mostly on the IVR and PV-LAA ridge on the left (88%), and on the roof and IVR on the right (78%). At repeat procedure, 38/39 patients had chronic PVR, predominantly on the IVR (61%) and PV-LAA ridge (21%) on the left, and on the roof, IVR, and floor of the right PVs (79%). There was minimal acute or chronic PVR posteriorly. Acutely PVR occurred close to the immediate EI site 60% of the time, but only 30% of the time chronically. Conclusion:Acute and chronic PVR sites have a preferential distribution. This may be determined by anatomical and technical factors. Knowledge of immediate EI sites may be beneficial acutely, but with chronic PVR a careful survey is required. These findings may help target ablation, improving safety and success. [source]