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Objectives: The present study was designed to investigate the feasibility and efficacy of single ablation catheter for complete circumferential pulmonary vein antrum (PVA) isolation. Background: Complete isolation of pulmonary veins is the mainstay for atrial fibrillation (AF) ablation. This is usually performed under the guidance of a circular catheter. Methods: One hundred and ten consecutive patients with paroxysmal AF were prospectively randomized into two groups: single-catheter approach (group 1) and double-catheter approach (group 2). After performing initial circumferential lesions, residual gaps were mapped and closed with single ablation catheter in group 1 or guided by a circular mapping catheter in group 2 using an electroanatomic mapping system (CARTO™ XP, Biosense-Webster Inc., Diamond Bar, CA, USA). Results: Complete bilateral PVA isolation was achieved in 22 of the 110 patients after initial ablation. All residual gaps could be correctly identified by activation mapping using single ablation catheter. The distribution of these residual gaps was asymmetric. In group 1, 25 gaps along the right PVA lesions and 49 gaps along the left PVA lesions were identified. All the residual gaps were closed with single-catheter approach. In group 2, 28 gaps on the right side and 53 gaps on the left side were identified using a circular catheter and closed with further ablations. The procedure data and clinical outcomes between the two groups were comparable. Conclusions: Single ablation catheter technique is feasible and as effective as circular catheter mapping in localizing the residual gaps for PVA isolation during ablation of paroxysmal AF. [ABSTRACT FROM AUTHOR]

Aims Evaluation of the clinical outcome of patients with hypertrophic obstructive cardiomyopathy (HOCM) and paroxysmal atrial fibrillation (AF) treated with complete pulmonary vein (PV) isolation guided by three-dimensional (3-D) electroanatomical (EA) mapping. Methods Circumferential radiofrequency (RF) ablation and continuous circular lesions (CCLs) around the left and right-sided PVs were performed in 4 highly symptomatic patients (2 males; age 57.5±8.3 years) with HOCM and anti-arrhythmic drug (AAD) refractory paroxysmal AF. Ablation was guided by 3-D EA mapping combined with conventional circumferential PV mapping. The endpoints of the ablation were defined as: (1) absence of all PV spikes documented with the two Lasso catheters within the ipsilateral PVs; and (2) no recurrence of the PV spikes within all PVs following intravenous administration of adenosine. Results The ablation endpoints were achieved in all patients. A repeat ablation was performed in one patient due to repetitive atrial tachycardia, 1 month after the initial procedure. During a follow-up of 5.8±2.7 months, all patients are free of AF recurrence. Short episodes of symptomatic AT were documented after the repeat procedure, and were well controlled with oral amiodarone in the patient. No procedure-related complications were observed. Conclusion The present study demonstrates that complete isolation of ipsilateral PVs guided by 3-D EA mapping is potentially effective for the treatment of highly symptomatic, drug refractory paroxysmal AF in patients with HOCM. [ABSTRACT FROM PUBLISHER]

Objectives: This study prospectively evaluated the role of a novel 3-dimensional, noninvasive, beat-by-beat mapping system, Electrocardiographic Mapping (ECM), in facilitating the diagnosis of atrial tachycardias (AT). Background: Conventional 12-lead electrocardiogram, a widely used noninvasive tool in clinical arrhythmia practice, has diagnostic limitations. Methods: Various AT (de novo and post-atrial fibrillation ablation) were mapped using ECM followed by standard-of-care electrophysiological mapping and ablation in 52 patients. The ECM consisted of recording body surface electrograms from a 252-electrode-vest placed on the torso combined with computed tomography–scan-based biatrial anatomy (CardioInsight Inc., Cleveland, Ohio). We evaluated the feasibility of this system in defining the mechanism of AT—macro–re-entrant (perimitral, cavotricuspid isthmus-dependent, and roof-dependent circuits) versus centrifugal (focal-source) activation—and the location of arrhythmia in centrifugal AT. The accuracy of the noninvasive diagnosis and detection of ablation targets was evaluated vis-à-vis subsequent invasive mapping and successful ablation. Results: Comparison between ECM and electrophysiological diagnosis could be accomplished in 48 patients (48 AT) but was not possible in 4 patients where the AT mechanism changed to another AT (n = 1), atrial fibrillation (n = 1), or sinus rhythm (n = 2) during the electrophysiological procedure. ECM correctly diagnosed AT mechanisms in 44 of 48 (92%) AT: macro–re-entry in 23 of 27; and focal-onset with centrifugal activation in 21 of 21. The region of interest for focal AT perfectly matched in 21 of 21 (100%) AT. The 2:1 ventricular conduction and low-amplitude P waves challenged the diagnosis of 4 of 27 macro–re-entrant (perimitral) AT that can be overcome by injecting atrioventricular node blockers and signal averaging, respectively. Conclusions: This prospective multicenter series shows a high success rate of ECM in accurately diagnosing the mechanism of AT and the location of focal arrhythmia. Intraprocedural use of the system and its application to atrial fibrillation mapping is under way. [ABSTRACT FROM AUTHOR]