Circumferential Pulmonary Vein Research Articles

Delayed Gadolinium Enhancement Magnetic Resonance Imaging Detected Anatomic Gap Length in Wide Circumferential Pulmonary Vein Ablation Lesions Is Associated With Recurrence of Atrial Fibrillation.

There is limited knowledge about the impact of anatomic gaps as assessed by delayed gadolinium enhancement cardiac magnetic resonance on atrial fibrillation (AF) recurrence after first pulmonary vein (PV) isolation. Consecutive patients underwent delayed gadolinium enhancement cardiac magnetic resonance 3 months after radiofrequency circumferential PV isolation. Delayed gadolinium enhancement cardiac magnetic resonance images were assessed from 360 PV resulting in 2880 segments in the 2×8-segment model from 94 patients (52±11 years, 62% paroxysmal AF). Left atria were segmented using dedicated software. Anatomic gap was defined as discontinuation of the ablation line by ≥3 mm. Relative gap length was calculated as absolute gap length divided by the total length of the ablation line. AF recurrence was assessed after a mean follow-up duration of 15±10 months Results: Mean number of anatomic gaps was 5.4 per patient. Recurrence within the first year of ablation was observed in 21 patients with paroxysmal AF (36%) and 19 patients with persistent AF (53%). In the univariate analysis, CHA2DS2-VASc score, AF type, and relative gap length were predictive of recurrence. In the multivariate analysis, only relative gap length was significantly associated with recurrence (hazard ratio, 1.16 [1.02-1.31] per each 10% of gap). The total relative gap length but not the number of anatomic gaps in the PV ablation line as assessed by delayed gadolinium enhancement cardiac magnetic resonance was associated with AF recurrence 1 year after first PV isolation. An increase of 10% relative gap length increased the likelihood of AF recurrence by 16%.

Catheter ablation of paroxysmal atrial fibrillation using high-density mapping-guided substrate modification.

This study aimed to evaluate the effect of substrate modification in paroxysmal atrial fibrillation (AF) patients prior to circumferential pulmonary vein isolation (CPVI). Patients without left atrial low-voltage and/or scar areas were defined as Group A. Patients with left atrial low-voltage and/or scar areas underwent regular CPVI (Group B) or substrate modification after CPVI (Group C). The procedural success rate and differences in the left atrial diameter (LAD) among groups were compared at 1 year postoperatively. The procedural success rate in Group C was comparable to that in Group A (P>0.05) and was significantly higher than that in Group B (P<0.01). The LAD of patients in Groups A and C significantly decreased at 1 year postoperatively compared to that prior to the surgery (P<0.05). However, no significant difference was noted in Group B. Our study demonstrated that substrate modification could contribute to the single catheter ablation surgery success rate in patients with paroxysmal AF and narrow LAD.

Abstract 16625: Electrical Activity in the Blind Spot of Lasso Guided PVI

Introduction: The primary goal of AF ablation are complete and durable lesions in a circumferential line around all ipsilateral pulmonary veins. But there is a highly complex and multilayered arrangement of myocardial fibers around the orifice of the pulmonary veins, allowing for unpredictable ways of electrical conduction in this area. Hypothesis: The Lasso-catheter records signals at least one or more millimeters inside the pulmonary veins, but PVI usually is intended by a circumferential line at least several millimeters outside the veins. High density mapping was used to determine whether electrical activity can be detected in the blind spot between the circumferential ablation line on the atrial side and the site of the Lasso-catheter in the pulmonary veins. Methods: Patients scheduled for their first PVI underwent a circumferential radiofrequency ablation of the ipsilateral pulmonary veins. The PVI was verified by 1) an exit- and entryblock via all 20 electrodes of the Lasso 2515 variable, 2) a negative adenosine test and 3) unexcitability along the ablation line. After successfully completing all 3 tests an additional high density mapping with was performed. Results: We included 34 consecutive patients (61 +/- 10 years, 9 females), 28 patients had paroxysmal and persistent AF, 6 patients longstanding persistent AF. Complete PVI was achieved in all patients, verified by all 3 tests. Additional high density mapping with 7023 +/- 645 EGMs per left atrium revealed no electrical activity within the circumferential ablation line in 13 patients (38%), but in a majority of 21 patients (62%) electrical activity beyond the circumferential ablation line could be detected: in 12 of these patients (57%) in one region and in further 9 patients (43%) in several regions. The carina between the right pulmonary veins was the region were residual electrical activity was detected most frequently (15 patients, 71%). The pulmonary veins themselves appeared isolated in all 34 patients (100%) in the high density mapping. Conclusions: High density mapping appeared to detect electrical activity in a hitherto blind spot of Lasso-controlled PVI. Ablation of this discrete electrical activity beyond the circumferential lines might be of additional importance for durable PVI.

Atrial Fibrillation Mechanisms and Implications for Catheter Ablation.

AF is a heterogeneous rhythm disorder that is related to a wide spectrum of etiologies and has broad clinical presentations. Mechanisms underlying AF are complex and remain incompletely understood despite extensive research. They associate interactions between triggers, substrate and modulators including ionic and anatomic remodeling, genetic predisposition and neuro-humoral contributors. The pulmonary veins play a key role in the pathogenesis of AF and their isolation is associated to high rates of AF freedom in patients with paroxysmal AF. However, ablation of persistent AF remains less effective, mainly limited by the difficulty to identify the sources sustaining AF. Many theories were advanced to explain the perpetuation of this form of AF, ranging from a single localized focal and reentrant source to diffuse bi-atrial multiple wavelets. Translating these mechanisms to the clinical practice remains challenging and limited by the spatio-temporal resolution of the mapping techniques. AF is driven by focal or reentrant activities that are initially clustered in a relatively limited atrial surface then disseminate everywhere in both atria. Evidence for structural remodeling, mainly represented by atrial fibrosis suggests that reentrant activities using anatomical substrate are the key mechanism sustaining AF. These reentries can be endocardial, epicardial, and intramural which makes them less accessible for mapping and for ablation. Subsequently, early interventions before irreversible remodeling are of major importance. Circumferential pulmonary vein isolation remains the cornerstone of the treatment of AF, regardless of the AF form and of the AF duration. No ablation strategy consistently demonstrated superiority to pulmonary vein isolation in preventing long term recurrences of atrial arrhythmias. Further research that allows accurate identification of the mechanisms underlying AF and efficient ablation should improve the results of PsAF ablation.

Impact of a prolonged interatrial conduction time for predicting the recurrence of atrial fibrillation after circumferential pulmonary vein isolation of persistent atrial fibrillation.

There are some cases that are difficult to cure with only circumferential pulmonary vein isolation (CPVI) of persistent atrial fibrillation (PerAF). Recently, prolonged interatrial conduction times (IACTs), which seem to be associated with progressive remodeled atria, have been reported as a predictor of new-onset AF. This study aimed to investigate the prognostic value of a prolonged IACT for predicting AF recurrences after CPVI of PerAF. One hundred thirteen patients who underwent CPVI without an empirical substrate modification of PerAF were retrospectively analyzed. The IACT was defined as the interval from the earliest P-wave onset on the ECG to the latest activation in the coronary sinus and was measured after achieving the CPVI and conversion to sinus rhythm. During a mean 22.7-month follow-up after the initial procedure, 56 patients (50%) had AF recurrences. Patients with AF recurrence had a longer IACT than those without AF recurrence (p < 0.001). The best discriminative cut-off value for the IACT was 123ms (sensitivity 53%, specificity 85%). In a Cox multivariate analysis, a prolonged IACT of ≥ 123ms was the only independent predictor (hazard ratio: 2.38; 95% confidence interval: 1.36-4.16, p = 0.002) of being associated with the incidence of an AF recurrence. Even after multiple CPVI procedures, patients with an IACT ≥ 123ms had a higher AF recurrence rate than those with an IACT < 123ms (p = 0.002). In conclusion, a prolonged IACT of ≥ 123ms may be a useful marker for predicting AF recurrences after both initial and multiple CPVI procedures for PerAF.

Efficacy of sole pulmonary vein isolation in patients with nonparoxysmal atrial fibrillation without significant left atrium scar

Catheter ablation strategies for nonparoxysmal atrial fibrillation (NPAF) are in varied forms. The mechanisms that circumferential pulmonary vein isolation (CPVI) alone could achieve success in some of the patients with NPAF are not well studied. This study sought to assess the clinical outcome of only CPVI approach in NPAF patients without significant left atrium scar. A total of 241 consecutive patients with NPAF undergoing an initial ablation procedure were studied. After CPVI, cavotricuspid isthmus ablation and direct current cardioversion, high-density atrial voltage mapping was performed during sinus rhythm. Transitional-voltage zone (TZ) was defined as 0.4-1.3mV, and low-voltage zone (LVZ) as<0.4mV. No LVZs were identified in 101 patients (41.9%), and only CPVI was performed. Among the patients without LVZs, single-procedure freedom from atrial fibrillation (AF)/atrial tachycardia was achieved in 73 patients (72%), while 28 patients (28%) had AF recurrence with mean follow-up of 29 ± 14 months. TZ index (TZi) was deduced by calculating the ratio of all TZ points over the total number of points and was found to be a univariate predictor of recurrence after a single procedure (P=0.047). The CPVI alone strategy for patients with NPAF can be performed in highly selective patients without LVZs. TZi may reflect healthy extent of left atrium, which has trend toward the association with AF recurrence.

Pulmonary vein volume predicts the outcome of radiofrequency catheter ablation of paroxysmal atrial fibrillation.

PurposeCatheter ablation of atrial fibrillation (AF) is an effective therapy for selected groups of patients. We evaluated whether quantification of left atrium (LA) or pulmonary vein (PV) by using multi-detector computed tomography (MDCT) may predict the success rate of PV isolation procedure.MethodsWe included 118 patients younger than 65 years with symptomatic AF (73 paroxysmal, PAF; 45 non-paroxysmal, non-PAF). All patients underwent 256-slice MDCT prior to circumferential PV isolation to evaluate anatomy, volume and dimensions of LA and PV.ResultsAfter a mean follow-up of 14 months, complete success was achieved in 50 patients (68.5%) of PAF and in 26 patients (57.8%) of non-PAF. In the PAF group, total PV volume was found to be an independent predictor of AF recurrence, whereas LA volume was not. Logistic regression analysis showed that the probability of AF recurrence was higher in patients with total PV volume greater than 12.0 cm3/BSA (m2) (AUC 0.682, 95%CI 0.541―0.822). In the non-PAF group, no independent risk factor of LA or PV size was observed for the postoperative recurrence.ConclusionsThe PV volume quantification may predict the success of AF ablation in PAF patients.

Low voltage areas in paroxysmal atrial fibrillation: The prevalence, risk factors and impact on the effectiveness of catheter ablation

BackgroundThe prevalence, risk factors of left atrial low voltage areas (LVA) in paroxysmal atrial fibrillation (PAF) and the impact of LVA on the effectiveness of circumferential pulmonary vein isolation (CPVI) were not fully clarified. MethodsOne hundred fifty patients (mean age 64.7 years, 89 males) with PAF were consecutively enrolled to undergo CPVI. Prior to ablation a contact force sensing ablation catheter was utilized for LVA mapping in sinus rhythm. The patients were graded based on the proportion of LVA (LVA%): non LVA, mild (LVA% ≤ 10%), moderate (LVA% 10%–<20%) and severe (LVA% ≥ 20%), and were followed up for 12 months after initial CPVI. ResultsThere were 56 in non LVA, 54 in mild LVA, 22 in moderate LVA and 18 in severe LVA. The prevalence of LVA was 62.7% in this PAF cohort, with the most frequent localization at anterior free wall (35.3%), PV antrum (22%) and septum (14.7%). Female gender (OR 3.634, 95% CI 1.704–7.751, P = 0.001) and left atrial surface area (LASA) (OR 1.024, 95% CI 1.000–1.048, P = 0.048) were risk factors of LVA. LVA% exceeding10% was associated with poor effectiveness of CPVI. LVA grade (HR 1.633, 95% CI 1.122–2.378, P = 0.011) was an independent predictor for AF recurrence after initial ablation. ConclusionsLVA affected >60% of patients with PAF. Female gender and LASA were two risk factors of LVA. LVA grade was an independent predictor for AF recurrence following CPVI.

Long-term outcome of radiofrequency catheter ablation for persistent atrial fibrillation.

Catheter ablation has been wildly used to treat atrial fibrillation (AF) and has achieved a better efficacy for paroxysmal AF (PAF) but not for persistent AF (PerAF). Furthermore, a few data on the efficacy and safety of catheter ablation for PerAF were reported. This study aimed to investigate long-term efficacy of radiofrequency catheter ablation (RFCA) for PerAF and explore predictors of late recurrence of atrial fibrillation (LRAF).A total of 92 consecutive patients with PerAF (64 males, aged 56.42 ± 11.24 years) were enrolled in this study and accepted circumferential pulmonary vein isolation (CPVI) alone or CPVI combined additional ablation.Maintenance rate of sinus rhythm (SR) was 40.2% after a single procedure with median follow-up of 15 months and 52.2% after mean 1.3 ± 0.6 procedures with median follow-up of 26 months. Long-term SR maintenance rate was no statistical difference between patients with CPVI alone and with CPVI combined additional ablation (48.6% vs 35.1%, log rank test, P = .152). Patients with AF duration < 24 months had a higher long-term SR maintenance rate than those with AF duration ≥ 24 months (55.6% vs 30.4%, log rank test, P = .022). AF duration (OR = 1.015, 95%CI 1.001–1.030, P = .015), and early recurrence of AF (ERAF) (OR = 10.654, 95%CI 3.853–29.460, P < .001) were predictors of LRAF after a single procedure.In conclusion, long-term maintenance SR rate was 52.2% in patients with PerAF after multiple procedures with a median over 2-year follow-up. Patients with AF duration < 24 months had better outcome. AF duration and ERAF were predictors of LRAF after a single procedure.

The impact of the CartoSound® image directly acquired from the left atrium for integration in atrial fibrillation ablation.

Intracardiac echocardiographic (ICE) imaging might be useful for integrating three-dimensional computed tomographic (CT) images for left atrial (LA) catheter navigation during atrial fibrillation (AF) ablation. However, the optimal CT image integration method using ICE has not been established. This study included 52 AF patients who underwent successful circumferential pulmonary vein isolation (CPVI). In all patients, CT image integration was performed after the CPVI with the following two methods: (1) using ICE images of the LA derived from the right atrium and right ventricular outflow tract (RA-merge) and (2) using ICE images of the LA directly derived from the LA added to the image for the RA-merge (LA-merge). The accuracy of these two methods was assessed by the distances between the integrated CT image and ICE image (ICE-to-CT distance), and between the CT image and actual ablated sites for the CPVI (CT-to-ABL distance). The mean ICE-to-CT distance was comparable between the two methods (RA-merge = 1.6 ± 0.5mm, LA-merge = 1.7 ± 0.4mm; p = 0.33). However, the mean CT-to-ABL distance was shorter for the LA-merge (2.1 ± 0.6mm) than RA-merge (2.5 ± 0.8mm; p < 0.01). The LA, especially the left-sided PVs and LA roof, was more sharply delineated by direct LA imaging, and whereas the greatest CT-to-ABL distance was observed at the roof portion of the left superior PV (3.7 ± 2.8mm) after the RA-merge, it improved to 2.6 ± 1.9mm after the LA-merge (p < 0.01). Additional ICE images of the LA directly acquired from the LA might lead to a greater accuracy of the CT image integration for the CVPI.

Low heart deceleration capacity imply higher atrial fibrillation-free rate after ablation

How deceleration capacity (DC) and acceleration capacity (AC) of heart rate associated with atrial fibrillation (AF) and ablation is still not clear. The dynamic changes of AC, DC and conventional heart rate variability (HRV) parameters were characterized in 154 subjects before circumferential pulmonary veins isolation (CPVI) and three days, 3 months and 6 months after CPVI. The DCs of the recurrent group decreased significantly at each time point after CPVI; the DCs of the recurrence-free group before CPVI and three days, 3 months and 6 months after CPVI were 7.06 ± 1.77, 3.79 ± 1.18, 4.22 ± 1.96 and 3.97 ± 0.98 ms respectively, which also decreased significantly at each time point and were significantly lower than these of recurrent group. Conversely, the AC of recurrent and recurrence-free groups increased significantly at each time point after CPVI; the ACs of recurrence-fee group were significantly higher than these of recurrent group at each time point. No stable difference trend of HRV parameters was found between two groups. Further Kaplan–Meier analysis showed that DC < 4.8 ms or AC ≥ −5.1 ms displayed significant higher recurrence-free rates. In conclusion, high AC and low DC imply higher AF-free rate after ablation.

Evaluation of the atrial substrate based on low-voltage areas and dominant frequencies after pulmonary vein isolation in nonparoxysmal atrial fibrillation.

BackgroundThis study aimed to evaluate the atrial substrate in the left atrium (LA) by low‐voltage areas (LVAs) and high‐dominant frequencies (DFs) after circumferential pulmonary vein isolation (PVI) in nonparoxysmal atrial fibrillation (AF).MethodsIn 70 patients with nonparoxysmal AF patients (41 persistent AF), LA voltage maps were created during sinus rhythm by external cardioversion after PVI and DF mapping. The patients were divided into AF‐free and AF‐recurrent groups.ResultsThe AF freedom rate without antiarrhythmic drugs was 69.0% after PVI after 1 procedure during a 12‐month follow‐up. There was a significant difference in the LVA (<0.5 mV)/LA surface area after PVI between the AF‐free and AF‐recurrent groups (15% vs 23%, P = .033). AF freedom was significantly greater in those with LVAs of ≤24% than in those with LVAs of >24% during 12 months of follow‐up (78.6% vs 53.8%, Log‐rank test P = .020). Fifty‐six (72%) of the 78 high‐DF sites (≥8 Hz) overlapped with LVAs. Thirty‐one (55%) of 56 high‐DF sites overlapped with LVAs that existed at LVA border zones. There were no significant differences in number of high‐DF sites that overlapped with LVAs in the LA between the two groups. However, in persistent AF patients, the max‐DF value in the LA exhibited a significant difference between the two groups (P = .008).Conclusions LVAs were associated with AF recurrences after PVI in nonparoxysmal AF patients and overlapped with many high‐DF sites. PVI alone may be enough to treat patients with mild‐to‐moderate extent (≤24%) of LVAs.

Usefulness of a Low Resting Heart Rate to Predict Recurrence of Atrial Fibrillation After Catheter Ablation in People ≥65 Years of Age

A low resting heart rate (RHR) is associated with an increased risk of atrial fibrillation (AF), and this is common in older people. Whether a low RHR in older people can predict recurrence of AF after catheter ablation is unclear. A total of 329 consecutive patients ≥65 years of age with paroxysmal AF who underwent index circumferential pulmonary vein isolation were prospectively enrolled. A 10-second standard resting 12-lead electrocardiogram in sinus rhythm was recorded to measure the RR interval, P-wave duration, and PR interval. The RHR was calculated based on the mean RR interval. During a mean follow-up period of 17.0 ± 8.3 months (range, 3 to 32 months), 96 (29.2%) patients developed recurrence of AF. The AF recurrence rate was 46.2%, 32.3%, and 25.4% in patients with an RHR <50, 50 to 59, and ≥60 beats/min, respectively (log-rank test, p = 0.009). Cox regression analysis with adjustment for P-wave duration and the CHADS2 score showed that an RHR <50 beats/min (hazard ratio [HR] 1.92, 95% confidence interval [CI] 1.12 to 3.28, p = 0.017), advanced interatrial block (HR 1.82, 95% CI 1.09 to 3.04, p = 0.022), and left atrial diameter (HR 1.05, 95% CI 1.00 to 1.09, p = 0.029) were independent predictors of recurrence of AF after catheter ablation. In conclusion, in people ≥65 years of age, an RHR <50 beats/min is an independent predictor of AF recurrence in patients who have undergone catheter ablation for paroxysmal AF.

Clinical Outcome of Electrophysiologically Guided Ablation for Nonparoxysmal Atrial Fibrillation Using a Novel Real-Time 3-Dimensional Mapping Technique: Results From a Prospective Randomized Trial.

Clinical outcomes after ablation of persistent atrial fibrillation remain suboptimal. Identification of AF drivers using a novel integrated mapping technique may be crucial to ameliorate the clinical outcome. Persistent AF patients were prospectively enrolled to undergo high-density electrophysiological mapping to identify repetitive-regular activities (RRas) before modified circumferential pulmonary vein (PV) ablation. They have been randomly assigned (1:1 ratio) to ablation of RRa followed by modified circumferential PV ablation (mapping group; n=41) or modified circumferential PV ablation alone (control group; n=40). The primary end point was freedom from arrhythmic recurrences at 1 year. In total, 81 persistent AF patients (74% male; mean age, 61.7±10.6 years) underwent mapping/ablation procedure. The regions exhibiting RRa were 479 in 81 patients (5.9±2.4 RRa per patient): 232 regions in the mapping group (n=41) and 247 in the control group (n=40). Overall, 185 of 479 (39%) RRas were identified within the PVs, whereas 294 of 479 (61%) in non-PV regions. Mapping-guided ablation resulted in higher arrhythmia termination rate when compared with conventional strategy (25/41, 61% versus 12/40, 30%; P<0.007). Total radiofrequency duration (P=0.38), mapping (P=0.46), and fluoroscopy times (P=0.69) were not significantly different between the groups. No major procedure-related adverse events occurred. After 1 year, 73.2% of mapping group patients were free from recurrences versus 50% of control group (P=0.03). Targeted ablation of regions showing RRa provided an adjunctive benefit in terms of arrhythmia freedom at 1-year follow-up in the treatment of persistent AF. These findings might support a patient-tailored strategy in subjects with nonparoxysmal AF and should be confirmed by additional larger, randomized, multicenter studies. URL: https://www.clinicaltrials.gov. Unique identifier NCT02571218.

Ten-Year Clinical Outcome After Circumferential Pulmonary Vein Isolation Utilizing the Hamburg Approach in Patients With Symptomatic Drug-Refractory Paroxysmal Atrial Fibrillation.

Circumferential pulmonary vein isolation (CPVI) is increasingly performed for the treatment of symptomatic drug-refractory paroxysmal atrial fibrillation. Long-term data for >10 years after CPVI are sparse. We investigated the long-term clinical outcome and progression of paroxysmal atrial fibrillation after double-lasso and 3-dimensional electroanatomical mapping-guided CPVI. From 2003 to 2004, 161 patients (mean age: 60±10 years) with symptomatic drug-refractory paroxysmal atrial fibrillation were prospectively enrolled and underwent electroanatomical mapping-guided CPVI. Right-sided and left-sided continuous circular lesions encircling the ipsilateral pulmonary veins were placed with irrigated radiofrequency energy. The procedural end point was the absence of pulmonary vein spikes 30 minutes after CPVI verified by 2 spiral catheters placed within the ipsilateral pulmonary veins (double-lasso technique). Major periprocedural complications occurred in 5 of 161 patients (3.1%). Follow-up was based on outpatient clinic visits, including Holter-ECGs and telephonic interviews. After a single procedure and median follow-up of 129.0 months (interquartile range, 124.7-133.1 months), stable sinus rhythm was present in 53 of 161 (32.9%) patients. Multiprocedural outcome after a mean of 1.73±0.9 procedures and a median follow-up of 123.4 months (interquartile range, 61.0-131.0 months) resulted in stable sinus rhythm in 101 of 161 patients (62.7%). Progression toward persistent atrial fibrillation was observed in 10 of 161 patients (6.2%). Ten-year single-procedural outcome of CPVI in patients with paroxysmal atrial fibrillation resulted in stable sinus rhythm in 32.9% and in 62.7% of patients after multiple procedures. The progression rate to persistent AF was remarkably low.

Optimalendpoint for catheter ablation of longstanding persistent atrial fibrillation: A randomized clinical trial.

In longstanding persistent atrial fibrillation (LPeAF), the ideal endpoint of ablation remains to be determined. This study was to explore the value of pursuing AF termination or no with the same strategy during ablation on the long-term outcomes in patients with LPeAF. Utilized "CCL" strategy is a fixed ablation approach consisting of circumferential pulmonary vein antrum isolation, ablation of complex fractionated atrial electrogram, and linear ablation between two anatomical structures (the mitral isthmus, left atrial roof). Note that 400 patients were randomized to group A (technical endpoint) and group B (pursuing AF termination). A group with technical endpoint had lower rate of acute AF termination (AF→sinus rhythm, 3.5%vs 18.1%; AF→atrial tachycardia, 23.7%vs 44.7%; P<0.01) and shorter duration of ablation (164.9 ± 20.8vs 223.4 ± 24.9, P<0.01), radiofrequency delivery time (69.8 ± 18.1vs 102.2 ± 26.3, P<0.01), and x-ray exposure time (18.2 ± 8.8vs 27.9 ± 12.4, P<0.01) than those in B group (pursuing AF termination). During follow-up, freedom from atrial arrhythmias didnotdifferbetweenthetwo groups after a single ablation procedure (46.5%vs 54.3%, P=0.12) and the final ablation procedure (60.1%vs 65.8%, P=0.24). In patients of LPeAF, pursuing AF termination during ablation was associated with similar long-term clinical outcome compared to that with technical endpoint. Ablation to termination is not the best strategy during ablation.

Insights into ablation of persistent atrial fibrillation: Lessons from 6-year clinical outcomes.

Ablation of persistent atrial fibrillation (AF) is a potential treatment option for symptomatic patients. We sought to evaluate the critical role of circumferential pulmonary vein isolation (CPVI) in the ablation of persistent AF. A total of 341 ablation procedures were performed in 174 consecutive patients with persistent AF. CPVI was performed in all patients, additional ablation was only performed if electrical cardioversion failed after CPVI. During a median follow-up (FU) of 89 (63; 89) months, stable sinus rhythm was documented in 42/170 (25%) patients after a single procedure and in 111/164 (68%) patients after 1.9 ± 1.1 procedures. Stable SR was achieved in 40/75 (53%) patients in whom only CPVI was performed during the index and repeat procedures and in 71/89 (79%) patients with CPVI plus additional ablation. The main predictor for ablation success was duration of persistent AF before the index procedure (P<0.001, HR ± CI: 1.608 [1.034, 1.103]). Responders to CPVI during the initial procedure had a significantly better multiple-procedure outcome after 42 months of FU compared to CPVI nonresponders (P=0.0365). Conversion during the index procedure had no impact on clinical outcomes (P=0.0903). Persistent AF regressed to paroxysmal AF in 16% of patients. We demonstrate a 25% single- and 68% multiple-procedure success in patients with persistent AF, while stable SR was achieved in 53% of patients with pure CPVI during all procedures and in 79% of patients with CPVI plus additional ablation. Only duration of persistent AF before ablation had a statistically significant impact on ablation outcome.

Sequential ultra-high density contact mapping of persistent atrial fibrillation: An efficient technique for rotors identification

Whether ultra-high density (UHD) contact mapping (Rhythmia) may be used to map activation of atrial fibrillation (AF) is unknown. We sequentially mapped the left atrial (LA) activation during AF ablation (circumferential pulmonary vein isolation–CPVI, followed by defragmentation). Time reference was an LA appendage (LAA) electrogram (EGM). Points were acquired with respiratory gating if reference, mapped EGM (10 ms tolerance) and electrode location were stable. For fragmented EGM the timing of the surrounding area was used. In case of extremely low voltage (< 0.01 mV) or lack of local statistical coherence no colour-code was displayed (grey area). Circular propagation around single points were defined as organized rotating drivers (see Fig. 1 ). AF was mapped in 17 patients (patients; 9 men, 68 ± 5 y). LA maps (162 ± 49 ml, 30947 ± 14061 EGM, 95 ± 26 cm 2 ) were acquired in 15.7 ± 6.5 minutes. In 70% of the cases, stable rotating drivers (mean 1.9, 1 to 5) with continuous activation in the centre were visualized. All patients had CPVI followed by ablation of the centre of rotational regions and at sites with fragmented bipolar EGM. After CPVI, LAA CL increased from 171 ± 10 to 199 ± 14 ms ( P = 0.02). Termination of AF without electrical cardioversion was obtained in 62%. Sequential UHD activation mapping of AF allows visualisation of areas of rotational activation that are always around a fragmented EGM and seem to be an appropriate target for ablation.

Subxiphoid Minimally Invasive Epicardial Ablation (Convergent Procedure) With Left Thoracoscopic Closure of the Left Atrial Appendage

The Convergent Procedure is a combined epicardial and endocardial ablation performed by a cardiac surgeon and electrophysiologist to treat symptomatic persistent and long standing persistent atrial fibrillation. The epicardial ablation is performed on the entire width of the posterior left atrial wall using monopolar radiofrequency via a subxiphoid incision. There is no sternotomy and cardiopulmonary bypass is not utilized. The surgical ablation is then followed by endocardial voltage mapping and ablation, allowing for complete lesion set creation. Left atrial appendage exclusion can be performed via left thoracoscopic approach at the same time as the surgical ablation. The Convergent Procedure is a truly hybrid, collaborative procedure which combines the strengths of minimally invasive cardiac surgery and percutaneous electrophysiologic techniques to treat a challenging disease process.

Cryoballoon Ablation for Atrial Fibrillation: a Comprehensive Review and Practice Guide.

The cryoballoon was invented to achieve circumferential pulmonary vein isolation more efficiently to compliment the shortcomings of point-by-point ablation by radiofrequency ablation (RFA). Its efficacy and safety were shown to be comparable to those of RFA, and the clinical outcomes have improved with the second-generation cryoballoon. The basic biophysics, implemental techniques, procedural recommendations, clinical outcomes, and complications of the cryoballoon are presented in this practical and systematic review.