Electrophysiological characteristics of localized reentrant atrial tachycardia occurring after catheter ablation of long-lasting persistent atrial fibrillation.
ABSTRACT Mapping of recurrent atrial tachycardia (AT) after extensive ablation for long-lasting persistent atrial fibrillation (AF) is complex. We sought to describe the electrophysiological characteristics of localized reentry occurring after ablation of long-lasting persistent AF.
Out of 70 patients undergoing catheter ablation of long-lasting persistent AF, 9 patients (13%, 55 +/- 8 years, 8 males) in whom localized reentry was demonstrated in a repeat ablation were studied. Localized reentry was defined as reentry in which the circuit was localized to a small area and did not have a central obstacle. The mechanism of AT was determined by electroanatomical and entrainment mapping.
Nine localized reentries with cycle length of 243 +/- 41 ms were mapped in 9 patients. The location of AT was the left atrial appendage in 4 patients, anterior left atrium in 2, left septum in 2, and mitral isthmus in 1. In all ATs, a critical isthmus of <10 mm in width was identified in the vicinity of the prior linear lesions or ostia of isolated pulmonary veins. Ablation of the critical isthmus, which was characterized by continuous low-voltage activity (median voltage: 0.15 mV, mean duration: 117 +/- 31 ms), terminated AT and rendered it noninducible. Additionally, ablation was performed for all of inducible ATs. At 11 +/- 7 months after the procedure, 8 of 9 patients (89%) were free from any arrhythmias.
After ablation of long-lasting persistent AF, localized reentry may arise from a site in the vicinity of the prior ablation lesions. Ablation of the critical isthmus eliminates the arrhythmia.
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ABSTRACT: Complex fractionated atrial electrograms (CFAEs) are a substrate modification target in patients with atrial fibrillation (AF). However, whether CFAEs can be also arrhythmogenic grounds of atrial tachycardia (AT) presenting after AF ablation remains to be determined. We investigated the relationship between CFAEs and the critical site of AT after CFAE-guided AF ablation. Seventy-two patients showing AT after pulmonary vein isolation and further CFAE-guided ablation were included. The termination sites of the 95 distinct ATs were annotated on color-coded CFAE cycle maps. Of the 95 ATs, 61 (64.2%) had a termination site at the border zone of CFAE or in a highly dense CFAE area. The cycle length (CL) of the ATs terminated in the CFAE area was significantly shorter than the CL of those terminated in the non-CFAE area. The cut-off CL for ATs terminated at the CFAE area was 270 ms, with sensitivity/specificity of 70%/75%. In 67.2% of the ATs terminating at the CFAE related area, the major termination sites were the anterior wall near the LA appendage, septum and roof, whereas the peri-mitral isthmus was the most common termination site of ATs in the non-CFAE area. The areas showing CFAE and their border zones were frequently associated with termination of ATs presenting after AF ablation. The mean CL of ATs originating near CFAEs was significantly shorter than that of those terminated in non-CFAE areas. The targeted CFAE areas also provided the arrhythmogenic milieu for AT developing after AF ablation. This article is protected by copyright. All rights reserved.Journal of Cardiovascular Electrophysiology 10/2013; · 3.48 Impact Factor
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ABSTRACT: AIMS: The aim of the study was to assess the impact of isthmus location of atypical atrial flutters/atrial tachycardias (ATs) on outcomes of catheter ablation. Atrial tachycardias are clinically challenging arrhythmias that can occur in the presence of atrial scar-often due to either cardiac surgery or prior ablation for atrial fibrillation. We previously demonstrated a catheter ablation approach employing rapid multielectrode activation mapping with targeted entrainment manoeuvrs. However, the role that AT isthmus location plays in acute and long-term success of ablation remains uncertain.METHODS AND RESULTS: Retrospective multicenter analysis of 91 consecutive AT patients undergoing ablation using a systematic four-step approach: (i) high-density activation mapping; (ii) analysis of atrial activation to identify wavefronts of electrical propagation; (iii) targeted entrainment of putative channels; and (iv) irrigated radiofrequency ablation of constrained regions of the circuit. Clinical outcomes, procedural details, and clinical profiles were determined. A total of 171 ATs (1.9 ± 1.0 per patient, 26% septal ATs) were targeted for ablation. The acute success rates were 97 and 77% for patients with either non-septal ATs or septal ATs, respectively (P = 0.0023). Similarly, the long-term success rates were 82 and 67% for patients with either no septal ATs or at least one septal AT, respectively (P = 0.1057). The long-term success rates were 75, 88, and 57% for patients with ATs associated with prior catheter ablation, cardiac surgery or MAZE, and idiopathic atrial scar, respectively.CONCLUSION: Catheter ablation of AT can be successfully performed employing a strategy of combined high-density activation and entrainment mapping. Septal ATs are associated with higher rates of acute and long-term recurrences.Europace 02/2013; · 2.77 Impact Factor
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ABSTRACT: Background Intraoperative atrial fibrillation (AF) ablation during cardiac surgery is a well-established treatment. However, tachycardia mechanisms, ablation strategies and long-term follow-up of atrial arrhythmias (AA) following intraoperative AF ablation (AFA) have not been previously studied in a large cohort of patients. Objective Eighty-two patients (48 male, median age of 65 years) with symptomatic recurrence of AA following intraoperative AFA underwent radiofrequency catheter ablation. Methods Regular atrial tachycardias (AT) were mapped using three-dimensional color-coded entrainment/activation mapping and eliminated by linear ablation. Pulmonary Vein (PV)-isolation was achieved in patients with LA-PV conduction after AT elimination. ResultsIn 85 (83%) out of a total of 103 regular ATs, the entire reentrant circuits were localized perimitrally (n = 27), around PVs (LPV or RPV, n = 9), around left atrial appendage (LAA) (n = 1), on left-sided atrial septum (n = 8), on atrioventricular nodal area (n = 1), on the posterior wall of LA (n = 1), along roof-septum-inferoposterior wall (n = 8), at coronary sinus ostium (n = 2), upper loop in RA (n = 1) and as cavotricuspid isthmus-dependent reentrant ATs (n = 27). Sixty-five (79%) patients received PV-isolation. Non-inducibility of any AT was reached at the end of all procedures. During a median follow-up time of 18 months, 69 patients (87%) were free of AA. Conclusion Reentrant AT appears in the majority of patients with recurrence of AA following intraoperative AFA. Detailed three-dimensional color-coded entrainment mapping was successfully obtained in the majority of patients suffering from reentrant AT after intraoperative AFA, facilitated the accurate identification of the entire reentrant circuit, and selection of optimal ablation lines.This article is protected by copyright. All rights reserved.Journal of Cardiovascular Electrophysiology 03/2014; · 3.48 Impact Factor