Catheter ablation for atrial fibrillation in heart failure:untying the Gordian knot

Atrial fibrillation(AF) and heart failure(HF) are complex clinical entities that occur concomitantly in a significant population of patients, and their prevalence is rising in epidemic proportions. Traditionally, both rate and rhythm control strategies have been regarded as equivalent in the management of dysrhythmia in this AF-HF cohort with escalation of treatment largely guided by symptoms. Both disorders are involved in an elaborate pathophysiological interplay with shared cardiovascular risk factors that contribute to the development and sustenance of both AF and HF. Recent studies and continued development of evidence to support catheter ablation for AF has brought into question the traditional belief in equivalence between rate and rhythm control. Indeed, recent trials, in particular the CASTLE-AF(Catheter Ablation versus Standard Conventional Therapy in Patients with Left Ventricular Dysfunction and Atrial Fibrillation) study, suggest that catheter ablation for AF improves survival and rates of hospitalisation in patients with concomitant HF and AF, threatening a paradigm shift in the management of this patient cohort. The evident mortality benefit from clinical trials suggests that catheter ablation for AF should be considered as a therapeutic intervention in all suitable patients with the AF-HF syndrome as these patients may derive the greatest benefit from restoration of sinus rhythm. Further research is needed to refine the evidence base, especially to determine which subgroup of HF patients benefit most from catheter ablation and what is the optimal timing.

Radiofrequency Ablation Mapping with Circumferential Catheter for Paroxys- mal Atrial Fibrillation Originating From the Pulmonary Veins

Objectives To assessed the feasibility and effectiveness of electrophysiological mapping of pulmonary veins with a circumferential 10 - electrode catheter and radiofrequency catheter ablation therapy for patients with paroxysmal atrial fibrillation. Background Standard mapping and ablation of focal sources of atrial fibrillation are associated with very long procedure times and low efficacy. Mapping and ablation pulmonary veins guide with a circular catheter could overcome these limitations. Methods 16 patients [male 11, female 5, mean age (51 ±14. 5) years] with paroxysmal atrial fibrillation refractory to antiarrhythmic drugs were included in this group. A circumferential 10 - electrode catheter was used to pulmonary vein mapping during sinus rhythm or CSd pacing to determine the origin of atrial premature contractions. When the ablative target pulmonary vein was found, the pulmonary vein potentials' distribution and activation were assessment pulmonary veins' ostial ablation was performed at the segments showing earliest activation of pulmonary vein potentials. The end point was designed: 1) elimination of pulmonary vein potential; 2) pulmonary vein potential dissociation from atrial waves; 3) atrial ectopic beats disappear. Results A total of 36 pulmonary veins were ablated, including 16 left superior, 12 right superior, 7 left inferior and 1 right inferior. 1 pulmonary vein in 2 patients was ablated, 2 pulmonary veins in 8 patients were ablated, 3 pulmonary veins were ablated in 5 patients and 4 pulmonary veins were ablated in 1 pa- tient. Procedure duration and fluoroscopy time respectively were 186. 7±63. 8 min and 51. 5±15. 0 min. During the follow-up 1-12 months, 11 patients (68. 7 % ) were free of AF without any antiarrhythmic drugs, 2 of them were reablation, effective in 3/16 (18. 7 % ) and unsuccessful in 2/16 (12. 6 % ) . 2 cases recurred with atrial premature, 1 was treated with amiodarone and the other was repeat electrophysiologi-cal mapping and ablation, 5 cases with paroxysmal a-trial fibrillation recurred, 3 of them were treated with amiodarone (2 cases) or sotalol (1 case) , one was implantled with DDDR pacemaker (having programmer of anti - atrial fibrillation), one was repeat ablation. PV's diameter in 2 of them reduced more than 50 % , but they were asymptomatic during the follow - up period. 1 case had pneumothorax complication and disappeared after 7 days. Conclusions This study suggests that careful mapping and elimination of these ectopic foci under the guide of circular catheter may have higher success rate and splendid future.

Results of Atrial Fibrillation Ablation in Patients With or Without a History of Atrial Flutter

Objectives There are two kind of atrial flutter during circumferential ablation for atrial fibrillation （AF）： new onset left atrial flutter （LAFL）, with a history of atrial flutter （AFL）. What is the relationship of AFL and AF？ Whether there are some differences in clinical course and mechanism between the new onset LAFL and the with a history of AFL remained unclear. The aim of this study was to assess the impacts of circumferential ablation on the occurrence of arrhythmias in follow-up in 2 groups： （1） patients with a history of AFL and AF, and （2） patients with new onset LAFL. Methods Data from 465 patients who had circumferential pulmonary vein ablation （CPVA） or segmental pulmonary vein ablation （SPVA） were analyzed. Patients with a history of AFL ablation and patients who had concomitant AFL ablation were included from analysis. Forty-one patients constituted the history of AFL group （group 1, aged 57±13 years, 7 females） and twenty-eight patients constituted the new onset LAFL group （group 2, aged 55±12 years, 6 females）, bipolar recordings were obtained from the tricuspid annulus, coronary sinus, interatrial septum and left atrium. Target sites were identified by early, fragmented or double potentials and by concealed entrainment. Linear lesions were created between target sites and nearby anatomical barriers （1） typical atrial flutter （cycle length, 242± 39 ms）. cavotricuspid isthmus ablation was performed. （2） new onset LAFL （cycle length, 282±153 ms）. 20 episodes of AAFs were documented in 20/28 （71.4%） patients. Target sites were identified around pulmonary veins （n=10）, gap in linear lesion （n=7）, left atrial roof lines （1 case）. For those cases the ablation line between PV and mitral annulus was performed. Patients in Group 2 had larger left atria, incidence of AFL pre-CPVA, and lower ejection fraction. Results There was no significant difference in post-CPVA AF recurrence between Groups 1 and 2, but AFL incidence after CPVA was higher in Group 2 （33% vs 4%, P 〈 0.0001）. Ablation of AFL in group 1 patients resulted in an 88% acute success rate （group2, 86%） and 12% （group2,17%） recurrence over a mean follow-up of 287 ±101 days.Condusions In patients with a history of atrial flutter, post-CPVA AF recurrence is similar to patients with new onset LAFL. However, LAFL is associated with a higher recurrence of AFL after PVAI. In a significant number of patients with LAFL, mitral Isthmus ablation is needed and can be performed effectively. Its eleetrophysiologieal eonse-quenees could be considered analogus to the results achieved by eavotrieuspid isthmus ablation.

Unipolar electrogram in identification of successful targets for radiofrequency catheter ablation of focal atrial tachycardia

Objective To analyze the unipolar electrogram from successful and unsuccessful ablation sites of focal atrial tachycardia (AT), and to evaluate its value in the identification of successful targets.Methods Fifteen consecutive patients with focal AT were referred for radiofrequency catheter ablation (RFCA). Both unipolar (from the tip electrode of ablating catheter) and bipolar (from the distal pair of electrode of ablating catheter) electrograms were used to identify the ablation targets of focal AT.Results Successful ablation was echieved in 14 patients. Radiofrequency energy was delivered at a total of 27 sites. The bipolar electrograms associated with successful ablation sites showed earlier atrial deflection relative to P wave onset (36 ms±15 ms vs 30 ms±11 ms, P <0.05) than the electrograms associated with failed ablation sites. At the 14 successful ablation sites, the unipolar electrograms displayed a completely negative atrial wave (“QS” morphology ) beginning with intrinsic deflection. However, at the 13 unsuccessful ablation sites,a “rS” morphology of atrial wave was shown on the unipolar electrogram.Conclusion The “QS” morphology of the atrial wave on unipolar electrograms appears to represent a reliable marker for identifying the successful ablation targets of focal AT, with a high sensitivity and specificity .

Recurrent atrial tachycardia and atrial fribrillation after circumferential pulmonary vein ablation:What’s the difference?

Background Recurrent atrial tachyarrhythmia （ATa） after circumferential pulmonary vein ablation （CPVA） includes atrial tachycardia （AT） and atrial fribrillation （AF）. However, whether there are some differences in clinical course and mechanisms between the recurrent AT and the recurrent AF remained unclear. This study was conducted to investigate the incidence, mechanism, clinical course of the recurrent AT and AF in patients under CPVA.Methods One hundred and thirty consecutive patients （M/F = 95/35 ） with highly symptomatic ano multiple antiarrhythmic drugs （AADs） refractory paroxysmal （ n = 91 ） or persistent （ n = 39 ） AF were included. The ablation protocol consisted solely of two continuous circular lesions around the ipsilateral pulmonary veins （PV） guided by CARTO system. The endpoint of CPVA is PV isolation. For patients with recurrent ATa within 2 months after the initial procedure, cardioversion with direct current was attempted if the ATa lasted for more than 24 hours. A repeat ablation procedure was performed only for patients with AADs refractory recurrent ATa and at least followed up for 2 months after the initial procedure.Results Within 2 months after the initial procedure, 52 patients （40. 0% ） had experienced episodes of symptomatic recurrent ATa. Among them, 23 patients （44.2%） with recurred AT alone （AT group ）, 14 patients （26.9%） with recurred AF alone （AF group）, and 15 patients （28.8%） with recurred AT and AF （AT plus AF group）. The delayed cure rate （65.2%） in AT group was significant higher than that in AF group （21.4%, P〈0.05） and AF plus AT group （26.7%, P 〈0.05）. A repeat ablation was performed in 21 patients, including 6 patients with recurrent AT alone, 8 patients with recurrent AF alone, and 7 patients with recurrent AF plus AT. The mean number of PV gaps was 1.2 ± 0. 4 in AT group, which was significantly lower than that in AF group （2.6 ± 0. 7, P 〈 0.05） and AF plus AT group （2.0 ± 0.6, P 〈 0.05）. Delayed cure rate and number of PV gaps between AF group and AF plus AT group were comparable （P 〉 0.05 ）. Conclusions Present study indicates that recurrent AT and AF after CPVA have the different clinical course and different electrophysiological findings during repeat procedure as follows： （1）After CPVA, spontaneous resolution of recurrent ATa was mainly found in patients with recurrent AT alone （about two thirds patients）. （2） The type of recurrent ATa after CPVA is associated with the numberof PV gaps.