Atrial arrhythmias following ostial or circumferential pulmonary vein ablation

Visualization of multiple catheters in left atrial ablation procedures. Comparison of two different 3D mapping systems

BACKGROUND

Visualization of intracardiac catheters placed in predefined anatomic locations is a cornerstone for successful atrial fibrillation (AF) ablation. The 3D mapping system Carto3™ (Biosense Webster, Diamond Bar, CA, USA) released in 2009 provides the possibility to visualize more than one intracardiac catheter at a time. The aim of the study was to evaluate the feasibility and safety of the system, to show the learning curve, and to compare it to the established Ensite NavX™ system regarding procedural handling parameters.

METHODS

A total of 100 patients were enrolled in the study. The Carto3™ system was used by a team of four specialized operators in 50 patients (mean age 62±9 years, paroxysmal AF n=28, persistent AF n=17, left atrial flutter n=5). Patients were consecutively enrolled and matched (regarding type of ablated arrhythmias, ablation strategy, left atrial size, age, and gender) with patients ablated during the same time period with the EnSite NavX™ system. In patients with paroxysmal AF, ostial pulmonary vein isolation (PVI) was performed. Patients with persistent AF underwent PVI plus additional ablation of complex fractionated atrial electrograms (CFAE) and patients with left atrial flutter were treated with specific lines.

RESULTS

In 50 case-control pairs, all procedures were performed as planned without complications in both groups except one cardiac tamponade in 1 patient in the Ensite NavX™ control group. The learning curve using the Carto3™ system was fast regarding x-ray time and procedural duration and reached the level of the EnSite NavX™ system after 15 and 25 patients, respectively.

CONCLUSION

The Carto3™ system with its feature of visualizing several catheters is feasible and safe compared to an established system, e.g., Ensite NavX™. The learning curve is steep regarding reduction of x-ray time and procedural duration.

Complete antral encirclement is not required for pulmonary vein isolation

BACKGROUND

Complete circumferential antral ablation may not be necessary for successful pulmonary vein (PV) isolation in patients with paroxysmal atrial fibrillation (AF).

OBJECTIVE

We examined the feasibility of a noncircumferential approach limited to segments of the antra required for PV-atrial conduction.

METHODS

During ablation for paroxysmal AF, each PV antrum was divided into six segments, and ablation was sequentially targeted to antral segments with the earliest activity until bidirectional isolation was achieved. Ablation at the ostium was avoided. Patients requiring complete circumferential ablation (circumferential group) were compared with those undergoing incomplete antral ablation (noncircumferential group) with respect to freedom from symptomatic atrial arrhythmia, procedure, and ablation times.

RESULTS

Ninety-nine patients underwent ablation with successful isolation of PVs (n = 37 circumferential; n = 62 noncircumferential). There were no significant differences in age, gender, AF duration, or LA size. Procedure time (202 ± 45 vs. 185 ± 47 minutes; P = .06) and ablation time (51 ± 15 vs. 41 ± 14 minutes; P = .004) were shorter in the noncircumferential group. During follow-up (12 ± 6 months), freedom from symptomatic recurrence was 73% in both groups (P = .97), with organized atrial tachycardia being more common in the circumferential group (P = .06). In 22 patients undergoing repeat study, PV reconnection was demonstrated in 82% and 81% of PVs in each group. Reconnection in the noncircumferential group occurred in previously ablated segments in 10 (77%) of 13 cases.

CONCLUSIONS

Noncircumferential antral ablation achieves similar success rates with shorter procedure and ablation times than circumferential ablation. Greater attention should be focused on producing permanent lesions rather than on completing antral encirclement after isolation is achieved.

Anatomic approach for ganglionic plexi ablation in patients with paroxysmal atrial fibrillation

There is evidence that parasympathetic denervation may prevent atrial fibrillation (AF) recurrences. This study aimed at applying an anatomic approach for ablation of atrial ganglionic plexi (GPs) in patients with paroxysmal AF. Nineteen patients with symptomatic, paroxysmal AF underwent anatomically guided radiofrequency ablation at the location of the 4 main left atrial GPs and were prospectively assessed for recurrence of AF or other atrial arrhythmia. This group was compared with 19 age- and gender-matched patients who previously underwent conventional circumferential pulmonary vein ablation. All ablation procedures were uneventful. Circumferential and GP ablations were accomplished with a radiofrequency delivery time of 28 +/- 5 versus 18 +/- 3 min (p <0.001) and a fluoroscopy time of 31 +/- 5 versus 18 +/- 5 min (p <0.001), respectively. Parasympathetic reflexes during radiofrequency ablation were elicited in 4 patients (21%). Arrhythmia recurred in 7 patients (37%) with circumferential ablation and 14 patients (74%) with GP ablation, during 1-year follow-up (p for log-rank test = 0.017). In 2 patients with GP ablation, left atrial flutters were documented in addition to AF during follow-up. Patients who underwent GP ablation had an almost 2.5 times higher risk of AF recurrence compared with those who underwent circumferential ablation (hazard ratio 2.6, 95% confidence interval 1.0 to 6.6, p = 0.038). In conclusion, anatomically guided GP ablation is feasible and safe in the electrophysiology laboratory, but this approach yields inferior clinical results compared with circumferential ablation.