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Aim: To define predictors of long-term outcome of a first repeat ablation solely consisting of re-isolation of reconnected pulmonary veins (PVs). Methods: Three hundred seven patients (age 59 ± 9%, 77% males, non-paroxysmal AF 43%) with recurrent AF after first PVI were studied. Re-isolation of reconnected PVs was guided by a circular mapping catheter and 3D mapping system using RF ablations. A PV was defined as "triggering" in case of spontaneous ectopy or AF paroxysms originating from the PV. Results: After a mean follow-up of 5.05 ± 2.21 years, 194 (63.2%) patients (73.0% in PAF vs 50.4% in non-PAF, log Rank <0.001) were free from AF. A "triggering" PV was present in 48 (15.6%) during the first PVI and in 52 (16.9%) at repeat. Independent predictors of recurrence were a non-PAF type (HR: 1.814, 95%CI: 1.090 - 3.018, p=0.022) and early recurrence (≤ 3 months) after first PVI (HR: 1.632, 95%CI: 1.091 - 2.443, p=0.017) while a "triggering" PV at first or repeat was a predictor of good outcome (HR: 0.574; 95%CI: 0.344 - 0.959; p=0.034) in the multivariable analysis. Conclusions: A repeat ablation solely consisting of re-isolation of reconnected PVs results in a high degree of long-term AF freedom, especially in PAF and in case of a PV trigger at index or repeat. Patients with non-PAF or experiencing early AF recurrence after first PVI are less responsive. [ABSTRACT FROM AUTHOR]

Triggering Pulmonary Veins and Recurrence After Ablation. Purpose: To identify procedural parameters predicting recurrence of atrial fibrillation (AF) after a first circumferential pulmonary vein isolation (CPVI). Methods: One hundred seventy-one patients undergoing CARTO-guided CPVI for recurrent AF with a left atrial (LA) diameter <45 mm were studied. Follow-up (symptoms and 7-day Holter) was performed at 1 and 3 months and every 3 months thereafter. Clinical and procedural characteristics between successful patients and patients undergoing repeat ablation were compared. In addition, procedural parameters of the first procedure were compared with parameters during repeat ablation. Results: After first CPVI, 80% of patients were free of AF without antiarrhythmic drugs after a follow-up (FU) of 28 ± 11 months (N = 136). Thirty-five patients (20%) had recurrence of AF of which 25 underwent repeat ablation (N = 25). Clinical characteristics did not differ between the successful and repeat group. A triggering vein during the index procedure was significantly more observed in the repeat group (56% vs 11%, P < 0.001). At repeat ablation, 2.6 ± 1.2 veins per patient were reconnected. Whereas there was no preferential reconnecting PV, all PVs triggering at index were reconnected (100%). Conclusions: (1) In patients with symptomatic recurrent AF, the presence of a triggering pulmonary vein during ablation is a paradoxical predictor for AF recurrence after PV isolation. (2) The consistent finding of reconnection of the triggering PV at repeat ablation, suggests that, in these patients, the triggering PV is the culprit vein and that reconnection invariably results in clinical AF recurrence. (3) The present study advocates a strategy of even more stringent PV isolation in case of a triggering PV. (J Cardiovasc Electrophysiol, Vol. 21, pp. 381–388, April 2010) [ABSTRACT FROM AUTHOR]

Background Triggers from thoracic veins have been implicated not only in the initiation, but also in the perpetuation of paroxysmal atrial fibrillation (PAF). To investigate their role we studied the distribution and stability of dominant frequencies (DFs) during PAF and the response to isolation of the triggering pulmonary vein (PV). Methods and Results Triggering structures inducing PAF were identified during isoproterenol challenge in 26 patients (15 males, 55 ± 8.5 years). During sustained PAF, sequential recordings were made with a decapolar circular mapping catheter from each PV and the left atrial posterior wall (LAPW), together with coronary sinus (CS) and right atrium (RA) recordings. DF was determined using fast Fourier transformation. Recordings were repeated after ≥15 minutes of PAF. Radiofrequency ablation was directed first at the triggering PVs. PAF initiated from the PVs in 24 patients and from RA in two. There was a significant frequency gradient from the triggering structure to the PVs, CS, LAPW, and RA (P < 0.0001). During the second recording, DF decreased at all sites (P < 0.02), but the frequency gradient remained unchanged. Despite isolation of the triggering PV, PAF continued in 53% of patients, although DF measured in the CS was lower. AF termination occurred with contralateral PV isolation in half of the remaining patients and further AF slowing was noted in the rest. Conclusions Triggering structures harbor the fastest activity during sustained PAF pointing to their leading role in arrhythmia perpetuation. However, nontriggering PVs also seem to contribute to PAF maintenance. [ABSTRACT FROM AUTHOR]

Background: Whether dissociated firing (DiFi) in isolated pulmonary veins (PVs) implies arrhythmogenicity of the particular PVand, therefore, a better outcome of PV isolation (PVI) for paroxysmal atrial fibrillation (PAF) is debated., Methods: Thirty-one patients undergoing their first PVI for PAF were studied. Isoproterenol was infused for induction, and the triggering PV was identified. During sustained PAF, sequential recordings were made with a decapolar circular mapping catheter from each PV. The dominant frequency (DF) was determined using fast Fourier transformation. Spontaneous DiFi was monitored for 30 min after PVI., Results: PAF was triggered by the PVs in all patients. Fourteen (45 %) patients had DiFi after PVI in at least one PV. It was recorded most commonly from the left upper (84 %) and lower (67 %), less commonly from the right upper (31 %) PV. Out of the 23 PVs with DiFi, 13 (57 %) showed sporadic ectopic beats while 10 (44 %) had sustained ectopic rhythm or isolated tachycardia. There was no difference in size between PVs with or without DiFi (5.9±1.2 vs. 5.6±1.0 cm ostial perimeter, p=0.40). Triggering PVs more commonly showed any DiFi, compared to nontriggering PVs (68 vs. 27 %, p=0.003) and more commonly had sustained DiFi (53 vs. 0 %, p<0.001). During PAF PVs with any DiFi showed faster maximal DF compared to PVs without DiFi (7.1±1.3 vs. 5.9±1.1 Hz, p=0.001). Higher maximal DF was recorded in PVs with sustained versus sporadic DiFi versus PVs without DiFi (7.5 ±0.9 vs. 6.8±1.6 vs. 5.9±1.1 Hz, respectively, p=0.002). Patients with DiFi after PVI had a longer mean time to recurrent PAF compared to those without DiFi (52 vs. 32 months, p=0.048)., Conclusions: Dissociated firing in isolated PVs is associated with their role in the initiation and maintenance of PAF.

Radiofrequency ablation (RFA) using the CARTO 3D mapping system is a common approach for pulmonary vein isolation to treat atrial fibrillation (AF). Linkage between CARTO procedural data and patients' electronical health records (EHR) provides an opportunity to identify the ablation-related parameters that would predict AF recurrence. The objective of this study is to assess the incremental accuracy of RFA procedural data to predict post-ablation AF recurrence using machine learning model. Procedural data generated during RFA procedure were downloaded from CARTONET and linked to deidentified Mercy Health EHR data. Data were divided into train (70%) and test (30%) data for model development and validation. Automate machine learning (AutoML) was used to predict 1 year AF recurrence, defined as a composite of repeat ablation, electrical cardioversion, and AF hospitalization. At first, AutoML model only included Patients' demographic and clinical characteristics. Second, an AutoML model with procedural variables and demographical/clinical variables was developed. Area under receiver operating characteristic curve (AUROC) and net reclassification improvement (NRI) were used to compare model performances using test data. Among 306 patients, 67 (21.9%) patients experienced 1-year AF recurrence. AUROC increased from 0.66 to 0.78 after adding procedural data in the AutoML model based on test data. For patients with AF recurrence, NRI was 32% for model with procedural data. Nine of 10 important predictive features were CARTO procedural data. From CARTO procedural data, patients with lower contact force in right inferior site, long ablation duration, and low number of left inferior and right roof lesions had a higher risk of AF recurrence. Patients with persistent AF were more likely to have AF recurrence. The machine learning model with procedural data better predicted 1-year AF recurrence than the model without procedural data. The model could be used for identification of patients with high risk of AF recurrence post ablation. [ABSTRACT FROM AUTHOR]

Introduction: Selective ipsilateral pulmonary vein isolation (SIPVI) has shown comparable efficacy in focal triggered atrial fibrillation (AF) versus isolation of all pulmonary veins (PVs), yet the sufficiency for such an ablation strategy to all patients is unclear. This study sought to identify a subgroup of patients for SIPVI and a subgroup of patients for bilateral PV isolation (BiPVI) with long-term success by comparing the clinical efficacy of SIPVI and BiPVI on PV-triggered AF., Methods and Results: One hundred and forty-two patients (106 males; mean age 51 ± 13 years) with focal PV triggered paroxysmal AF (PAF) were studied. Seventy patients underwent SIPVI and 72 patients underwent BiPVI. After the first ablation, 44 patients (44/70) in the SIPVI group and 54 patients (54/72) in the BiPVI group were free of AF without antiarrhythmic drugs, after a follow-up period of 36 ± 12 months (log-rank test P = 0.1594). In patients younger than 50 years of age with a left atrium (LA) diameter <40 mm, SIPVI had a high success rate (15/18, 83%) of freedom from AF. However, for patients aged ≥50 years with an LA diameter ≥40 mm, 10 of the 12 patients in the SIPVI group and only 5 of the 15 patients in the BiPVI group had a recurrence of AF (log-rank test P = 0.0173)., Conclusions: For focally triggered PAF, in patients aged <50 years with an LA diameter <40 mm, SIPVI of triggering PV had a high success rate of freedom from AF. However, in patients aged ≥50 years with an LA diameter ≥40 mm, BiPVI achieved a higher success rate., (© 2011 Wiley Periodicals, Inc.)

Introduction: Phase singularity (PS) mapping provides additional insight into the AF mechanism and is accurate in identifying rotors. The study aimed to evaluate the feasibility of PS mapping in identifying AF rotors using data obtained from an automatic ultra‐rapid high‐resolution mapping system with a high‐density mini‐basket catheter. Methods: Twenty‐three pigs underwent rapid right atrial (RA) pacing (RAP 480 bpm) for 5 weeks before the experiment. During AF, RA endocardial automatic continuous mappings with a mini‐basket catheter were generated using an automatic ultra‐rapid mapping system. Both fractionation mapping and waveform similarity measurements using a PS mapping algorithm were applied on the same recording signals to localize substrates maintaining AF. Results: Seventeen (74%) pigs developed sustained AF after RAP. Three were excluded because of periprocedural ventricular arrhythmia and corrupted digital data. RA fractionation maps were acquired with 6.17 ± 4.29 minutes mean acquisition time, 13768 ± 12698 acquisition points mapped during AF from 581 ± 387 beats. Fractionation mapping identified extensively distributed (66.7%) RA complex fractionated atrial electrogram (CFAE), whereas the nonlinear analysis identified high similarity index (SI > 0.7) parts in limited areas (23.7%). There was an average of 1.67 ± 0.87 SI sites with 0.43 ± 0.76 rotor/focal source/chamber. AF termination occurred in 11/16 (68.75%) AF events in 14 pigs during ablation targeting max CFAE. There was a higher incidence of rotor/focal source at AF termination sites compared with non‐AF termination sites (54.5% vs 0%, P = 0.011). Conclusions: The data obtained from ultra‐rapid high‐density automatic mapping is feasible and effective in identifying AF rotors/focal sources using PS technique, and those critical substrates were closely related to AF procedural termination. [ABSTRACT FROM AUTHOR]

Introduction: Both isoproterenol (Iso) and adenosine (Ado) are used to induce atrial fibrillation (AF) in the electrophysiology lab. However, the utility of Ado has not been systematically established. Objective: The purpose of this study was to compare Ado to Iso for the induction of paroxysmal AF. Methods: Forty patients (16 women; mean age, 60 ± 12 years) with paroxysmal AF, presenting for ablation were prospectively included of whom 36 (90%) received Ado (18‐36 mg) and/or Iso (3‐20 µg/min incremental dose) in a randomized order (26 [72%] received both drugs). Results: AF was induced with Iso in 15 of 32 (47%) and with Ado in 12 of 30 (40%) patients (P = 0.9). Iso‐triggered AF started from the left pulmonary veins (PVs) in 11 of 15 (73%), from the right PVs in 3 of 15 (20%), and from the coronary sinus (CS) in 1 of 15 (7%) cases. Ado‐induced AF episodes originated from the left PVs in 6 of 12 (50%), from the right atrium (RA) in 4 of 12 (33%), and from the CS in 2 of 12 (17%) cases. Altogether, Iso‐induced AF was more likely initiated from the PVs (93%) compared with Ado (50%) (P = 0.02). Ado‐induced non‐PV triggers were not predictive of arrhythmia recurrence after PV isolation. Conclusion: Ado much more frequently induces non‐PV triggers, especially from the RA. The clinical significance of these foci, however, is questionable. [ABSTRACT FROM AUTHOR]

Aims: The predictive value of induction studies after catheter ablation for atrial fibrillation (AF) is still debatable. To date, these studies have not been implemented in patients after cryoballoon (CB) ablation. Our aim was to analyse the clinical value of AF induction in patients treated by second generation CB for paroxysmal AF.Methods and results: Seventy patients underwent at first an isoproterenol challenge after pulmonary vein (PV) isolation to assess AF induction and early PV reconnections (EPVR). Patients without EPVR were evaluated for premature atrial contraction (PAC) induction; atrial ectopy was considered frequent (PAC+) if >1/10 cycles or >6/min. After restitution of baseline heart rate, rapid atrial pacing (RAP) was performed on all patients. AF induction by isoproterenol occurred only in 3/70 (4%) patients of whom 2/3 (66%) patients with an EPVR of a triggering vein. In the 62 patients without EPVR, PAC+ occurred in 17 patients (27%). RAP could induce AF in 23/70 (33%) patients. At a mean follow-up of 13.5 months, there were 11/70 (16%) AF recurrences. There was no significant difference in the AF recurrence rate between RAP inducible vs. non-inducible patients (log-rank P = 0.33). A 41% recurrence rate (7/17 patients) was seen in the PAC+ group with significantly different AF-free survival for PAC+ vs. PAC- patients (log rank P < 0.0001). PAC+ was the only independent determinant to predict AF recurrence after multivariate analysis.Conclusion: PAC occurrence in response to isoproterenol could predict AF recurrence after PV isolation by CB, while RAP showed no prognostic implication. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and represents a major burden to health care systems. Atrial fibrillation is associated with a 4- to 5-fold increased risk of thromboembolic stroke. The pulmonary veins have been identified as major sources of atrial triggers for AF. This is particularly true in patients with paroxysmal AF but not always the case for those with long-standing persistent AF (LSPAF), in which other locations for ectopic beats have been well recognized. Structures with foci triggering AF include the coronary sinus, the left atrial appendage (LAA), the superior vena cava, the crista terminalis, and the ligament of Marshall. More than 30 studies reporting results on radiofrequency ablation of LSPAF have been published to date. Most of these are observational studies with very different methodologies using different strategies. As a result, there has been remarkable variation in short- and long-term success, which suggests that the optimal ablation technique for LSPAF is still to be elucidated. In this review we discuss the different approaches to LSPAF catheter ablation, starting with pulmonary vein isolation (PVI) through ablation lines in different left atrial locations, the role of complex fractionated atrial electrograms, focal impulses and rotor modulation, autonomic modulation (ganglionated plexi), alcohol ablation, and the future of epicardial mapping and ablation for this arrhythmia. A stepwise ablation approach requires several key ablation techniques, such as meticulous PVI, linear ablation at the roof and mitral isthmus, electrogram-targeted ablation with particular attention to triggers in the coronary sinus and LAA, and discretionary right atrial ablation (superior vena cava, intercaval, or cavotricuspid isthmus lines). [ABSTRACT FROM AUTHOR]

Dissociated Pulmonary Vein Activity for Paroxysmal Atrial Fibrillation Background The role of dissociated pulmonary vein (DPV) activity after pulmonary vein isolation (PVI) is still poorly defined. We evaluated electrophysiological features and clinical impact on long-term outcome of DPV activity. Methods A total of 243 patients (mean age 63 ± 11 years; 63% males) undergoing PVI for paroxysmal atrial fibrillation (AF) were included. DPV activity was defined as a residual low frequency irregular PV rhythm. Patients were divided into Group 1 (presence of DPV activity; n = 65) or Group 2 (absence of DPV activity; n = 178). Results Of 936 isolated PVs, 112 PVs (12%) showed DPV activity. DPV activity was observed more frequently in PVs identified as AF triggers (P = 0.026). During follow-up (mean 12 ± 7 months), 15 of 65 patients of Group 1 (23%) and 57 of 178 patients of Group 2 (32%) had an arrhythmia recurrence (P = 0.23). At linear regression analysis, no independent predictor for clinical recurrence was identified. During the repeat ablation, 62 of 72 patients (86%) showed a recovered PV conduction without difference between the 2 groups. Clinically, all patients of Group 1 with PV reconnection (n = 13/15) had a recurrence of paroxysmal AF. In Group 2, 5 of 52 patients with reconnected PV developed non-PV related arrhythmias. Conclusion DPV activity occurred in 12% of PVs after PVI and was observed more frequently in PVs identified as AF triggers. DPV activity was not predictive for AF recurrence during follow-up. PV-left atrium reconnection involving PVs with DPV activity leads to AF. [ABSTRACT FROM AUTHOR]

Radiofrequency Applications for Spontaneous Dissociated Pulmonary Vein Activity Background The aim is to evaluate the efficacy of additional radiofrequency ablation (RFCA) for spontaneous dissociated pulmonary vein activity (DPV-spike) after PV isolation (PVI) in patients with paroxysmal atrial fibrillation (AF). Methods One hundred fifty-two consecutive patients with paroxysmal AF referred for RFCA were enrolled. When DPV-spike was documented after PVI, we randomly assigned these patients to receive additional RFCA for DPV-spike or only PVI. We divided them into 4 groups: 87 patients without DPV-spike after PVI (No-spike group), 31 without DPV-spike after additional RFCA (Successful group), 8 with remaining DPV-spike after additional RFCA (Unsuccessful group), and 26 with DPV-spike after only PVI (Spike group). AF recurrence was evaluated among the 4 groups. Results After PVI, DPV-spike was documented in 87 PVs (14%) from 65 patients. During 16 ± 9 months of follow-up, the incidence of the freedom from AF was significantly higher in the No-spike group than that in the Spike group and Unsuccessful group (P < 0.05), and tended to be higher in the Successful group than that in the Spike group and Unsuccessful group (P = 0.08 and 0.11, respectively). In a multivariate analysis, the remaining PV-spike after ablation was an independent predictor of AF recurrence (HR 2.44; CI 1.10-5.43, P < 0.05). No major complications including PV stenosis were observed during the follow-up. Conclusions DPV-spike after PVI may be associated with higher electrical activity within the PVs and may be one of the risk factors for AF recurrence. Additional RFCA for DPV-spike was effective to reduce the AF recurrence after PVI. [ABSTRACT FROM AUTHOR]

. (J Cardiovasc Electrophysiol, Vol. 22, pp. 638-646, June 2011) [ABSTRACT FROM AUTHOR]

Vagal Denervation After Pulmonary Vein Ablation. Introduction: Pulmonary vein (PV) isolation has proven to be an effective therapy for atrial fibrillation (AF). However, clinical evidence suggests that suppression of AF after PV isolation could not be fully attributed to the interruption of electrical conduction in and out of the PVs. Furthermore, little is known regarding the effects of ablation around the PVs on the atrial electrophysiological properties. We aimed to study the changes in atrial response to vagal stimulation (VS) after PV ablation (PVA). Methods: We studied 11 adult mongrel dogs under general anesthesia. Bilateral cervical sympathovagal trunks were decentralized. Propranolol was given to block sympathetic effects. Multipolar catheters were placed into right atrial appendage (RAA), distal and proximal coronary sinus (CSD, CSP), and left atrial free wall (LAFW). PVA was performed via trans-septal approach. Atrial effective refractory period (AERP) and vulnerability window (VW) of AF were measured with and without VS before and after ablation to isolate the PVs. Results: After ablation, AERP shortening in response to VS significantly decreased in the left atrium (43.64 ± 21.57 vs 11.82 ± 9.82 msec, P < 0.001 at LAFW; 50.91 ± 26.25 vs 11.82 ± 14.01 msec, P < 0.001 at CSP; 50 ± 31.94 vs 17.27 ± 20.54 msec, P < 0.005 at CSD), while the response to VS did not change significantly at RAA (58.18 ± 28.22 vs 50.91 ± 22.12 msec, P = 0.245). After ablation, atrial fibrillation VW during VS narrowed (20.63 ± 11.48 vs 5.63 ± 8.63 msec, P < 0.03 at LAFW; 26.25 ± 12.46 vs 5.00 ± 9.64 msec, P = 0.001 at CSP; 28.75 ± 18.47 vs 6.88 ± 7.53 msec, P < 0.02 at CSD, and 33.75 ± 24.5 vs 16.25 ± 9.91 msec, P = 0.03 at RAA). Conclusions: Ablation around the PV ostia diminishes left atrial response to VS and decreases the atrial VW. The attenuated vagal response after ablation may contribute to the suppression of AF. (J Cardiovasc Electrophysiol, Vol. 16, pp. 1-6, August 2005) [ABSTRACT FROM AUTHOR]