Noncontact Mapping-Guided Catheter Ablation of Atrial Fibrillation

Abstract

Circ J 2009; 73: 233 -241 revious studies have demonstrated that the pulmonary veins (PVs) are a source of triggers that initiate and perpetuate atrial fibrillation (AF), 1,2 so radiofrequency catheter ablation that electrically isolates the PVs has been used to treat AF. [1][2][3][4] To improve the clinical outcome, additional linear ablation to modify the substrate of AF has been proposed, 5-7 and we recently described an alternative approach of complete isolation of the posterior left atrium (LA), including all the PVs, for treating AF, namely the Box isolation. 8 However, this procedure is technically challenging because of variant atrial conductions, incomplete lesion lines or recovered conduction gaps being proarrhythmic. Editorial p 227Furthermore, during the procedure, non-PV foci can spontaneously occur, and atrial tachycardia or flutter can be induced after the Box lesion lines are completed. It is difficult to localize focal triggers and multiple conduction gaps, and analyze the mechanism of the atrial tachyarrhythmias with conventional point-to-point mapping. A noncontact mapping (NCM) system with a single-beat mapping capacity can facilitate the identification of the triggering sites of AF. 9-12 NCM allows fast recognition of the earliest depolarization sites, propagation patterns and conduction gaps, and also characterizes the relationship to the underlying anatomical structures. Therefore, we conducted this study to evaluate the feasibility and efficacy of the Box isolation using a NCM system. Methods Patient CharacteristicsThe study population consisted of 188 consecutive patients (166 men, 22 women; mean age 59±11 years) with paroxysmal (n=116), persistent (n=48) and longstanding persistent AF (n=24) who were referred for an electrophysiological study and catheter ablation. Persistent AF was defined as AF that was sustained beyond 7 days and requiring pharmacologic or electrical cardioversion. Longstanding persistent AF was defined as continuous AF of more than 1 year (mean, 91±69 months, range 12-240 months). The mean LA diameter was 41±6 mm and the mean ejection fraction was 63±8% as determined by echocardiography. A mean of 3.0±1.0 antiarrhythmic drugs had been administered, but failed to maintain normal sinus rhythm. None of the patients had been treated with amiodarone within the 6 months preceding the procedure. No structural heart disease was present in 65 patients. Valvular disease was documented in 22 patients, cardiomyopathy in 8, coronary artery disease in 8, and sick sinus syndrome in 2. Hypertension was present in 83 patients. Written informed consent was given by all patients. Electrophysiological StudyAll patients received oral anticoagulants for at least 1 month before the ablation. Transesophageal echocardiography was performed to exclude any LA thrombi and antiarrhythmic drugs were discontinued for 5 half-lives before the procedure. Three 5-Fr quadripolar electrode catheters (St Jude Medical (SJM), St Paul, MN, USA) were placed in the high right atrium, His bundle area, and...

Outcomes of long-standing persistent atrial fibrillation ablation: A systematic review

“…Only two studies 7,26 in this review clearly stated that all of their patients had continuous AF >12 months, which is the most recent classification of long-standing persistent AF 8 . All studies referring to their patient cohorts as chronic, persistent/long-standing persistent, or long-lasting persistent, but with enrollment criteria deviating from the contemporary definition, were included.…”

Box Isolation for Atrial Fibrillation

“…30,31) To improve the clinical outcome, extensive ablation, including multiple linear lesions and/or ablation of complex fractionated atrial electrograms (CFAE), has been widely adopted, particularly in patients with persistent AF or longstanding persistent AF.…”

Radiofrequency Catheter Ablation of Atrial Tachycardia Under Navigation Using the EnSite Array

“…Recently, the EA has been used in the ablation of atrial fibrillation and other tachyarrhythmias. [4][5][6] Notably, virtual beat-to-beat elucidation of AT activation accurately identifies the AT focus and elucidates the entire circuit of reentrant AT, even if the AT is multifocal, changes its reentrant circuit or is hemodynamically unstable. In the present study, we show how EA-guided RFCA works to eliminate AT.…”