Electrophysiology Mechanisms Of Regular Atrial Tachyarrhythmias During Catheter Ablation In Patients With Atrial Fibrillation

【Objective】 Circumferential pulmonary vein isolation (CPVI) is the main ablationapproach for atrial fibrillation, but the atrial tachyarrhymias(ATA)frequently developduring catheter ablation of atrial fibrillation（AF）,and the mechanism of ATA duringcombined pulmonary vein isolation(PVI) and complex fractionatedelectrogram-guided ablation (CFEA) has not been reported.The clinical challengesduring catheter ablation of AF is the occurrence of regular atrial tachyarrythmias(ATa)that are often difficult to deal with.The aim of this study was to define the mechanismsof atrial tachycardia (AT) that occurring during combined PVI and CFEA. to makeclear the relation between AT postablation and procedure of AF, to analysis theoutcome of ablation of AT, and to improve ablation technique and reduce theincidence of complications during ablation,such as AT.【Methods】 This study involved292patients with symptomatic,drug-refractory AFwho underwent intial CPVA from2009January to2011August in the Xiamen heartcentre.192patients were paroxysmal atrial fibrillation（PAF） and100patients werepersistent atrial fibrillation(PeAF). mean age (61±12) years. This study includingparoxysmal atrial fibrillation group and persistent atrial fibrillation group. We adoptedprogressive ablation. If AF was not terminated or occurred regular atrialtachyarrhymias（AT） after completion of pulmonary vein ablation,we took complexfractionated electrograms ablation(CFEA) and mapping the mechanism of AT.IF AFor AT persisted or remained inducible after CFEA,we adopted electrical conversion.The endpoint was noninducibility of AF/AT after sinus rhythm. The mechnisms ofthese ATs were determined through activation mapping by Carto XP3-dimensionalmaps or entrainment mapping. Then188patients with atrial fibrillation whounderwent intial CPVA from2010January to2011August. Univariate analysis andmultivariate analysis were carried out to assess the predicyive value including BNP、 EF、LA、LVD and the kind of atrial fibrillation on the AF term ination byablation.The statistically difference through X2test, t test and logistic regression.【Results】 For the192PAF patients,PVI alone rendered AF non-inducible in114patients,and converted into inducible atrial flutter(AFl) in78patients. A total of99ATS were mapped by carto-xp. There were20ATs which originated in the left atrialmechanism were unknown,recorded in the operation rules of atrial tachycardiaincidence,not included in the statistics of the mechanism. The tachycardiamechanisms were focal(19%), which originated in the aeptum,superior venacava(SV),crista terminalis, pulmonary vein(PV),left atrial focal and coronary sinus(CS). Themajor mechanism of tachycardia was macroreentry around large anatomisobstacles(81%), such as mitral isthmus,tricuspid isthmus and roof-dependent. Thenadditional isthmus.roof of LA and complex fractionated electrogram(CFE) ablation.For100PeAF patients,PVI and CFEA converted AF into sinus rhythm in33and intoAFl in50patients,while AF persisted in17patients. A total57ATs were mappedduring ablation. There were17ATs mechanisms unknown, which originated in theLA. The major mechanism of tachycardia like PAF were macroreentry(78.9%). Theincidence rate of AT after CPVA between the PAF and PeAF groups was nostatistically difference through X2test. But BNP maybe the predictor(p=0.027，RR0.999，95%CI0.998~1.000) of atrial fibrillation transfer to the regular atrialtachycardia during the ablation BY multivariate analysis.【Conclusion】 The major mechanism of atrial tachycardia that occurring duringcombined PVI and CFEA were macroreentry(78.9%),dependent mitral isthmus,tricuspid isthmus and roof-dependent. The incidence of atrial tachyarrhythmias(ATa)different in different ablation. Ablation may be an effective and safety measure forATs after catheter ablation. BNP maybe the predictive factors of atrial fibrillationtransfer to the regular atrial tachycardia during the ablation.