An Apparent Way of Achieving Proof of Pulmonary Vein Disconnection during Cryoballoon Ablation

Pulmonary vein isolation (PVI) has established itself as a standard therapy for paroxysmal atrial fibrillation (AF). Still, the most widely performed procedure of point-by-point distal-tip ablation using a 3-dimensional mapping system and a circular catheter to validate PVI remains a complex, elaborative, and time-consuming procedure. This explains the many efforts being made over the recent years to simplify and shorten PVI procedures without compromising the efficacy or the safety. The cryoballoon (Ablation Frontiers, Medtronic, Inc., Minneapolis, MN, USA) is a recently introduced "single shot ablation tool" to facilitate PVI. Initial studies on efficacy and safety of this device are encouraging in patients with paroxysmal AF. However, several controversies remain, such as the need for an additional circular mapping catheter to validate PVI and the lack of on-line PV recording during freezes. One of the most recent developments in this field is the Achieve circular mapping catheter (Ablation Frontiers, Medtronic, Inc.). We describe an apparent case in which this tool is used in conjunction with the cryoballoon. (PACE 2012; 35:e337-e340).     

A New Nonfluoroscopic Navigation System to Guide Pulmonary Vein Isolation

Different techniques have been proposed to treat atrial fibrillation (AF) by catheter ablation. This study compares a new three-dimensional (3D) nonfluoroscopic navigation system with conventional fluoroscopy to guide pulmonary vein (PV) isolation. A total of 60 consecutive patients with paroxysmal or persistent AF were randomly assigned to 3D-guided ablation (group 1, n = 30), versus conventional fluoroscopy guidance ablation (group 2, n = 30). Complete PV isolation was achieved in both groups. The mean duration of fluoroscopy exposure (22 ± 8 vs 56 ± 10 minutes), and radiofrequency delivery (5 ± 1 vs 10 ± 3 minutes) were significantly shorter in group 1 than in group 2, P < 0.05 for both comparisons). The mean procedural time in group 1 was longer (225 ± 15 minutes) than in group 2 (156 ± 10 minutes, P < 0.05) due to the learning curve and time spent to generate the 3D maps. Over a mean follow-up of 7 ± 2 months, 6 patients (20%) in group 2 had AF recurrences compared to 3 patients (10%) in group 1 (ns). The new nonfluoroscopic 3D system allows a high-resolution reconstruction of the left atrium and PVs. It significantly reduces the mean radiofrequency delivery and fluoroscopy times as opposed to ablation performed under fluoroscopy guidance.     

Atrial Flutter Ablation in Inducible Patients during Pulmonary Vein Atrum Isolation: A Randomized Comparison

Background: The incidence of atrial flutter (AFL) post pulmonary vein antrum isolation (PVAI) in patients with atrial fibrillation (AF) is reported to be between 8% and 20%. The need for right or left AFL ablation during the initial PVAI procedure remains controversial. We prospectively compared mapping and ablation versus no ablative treatment of inducible AFL during PVAI. Methods and Results: In 220 patients (167 men, mean age 56 ± 15 years) with symptomatic AF presenting for PVAI, burst pacing from the high right atrium and coronary sinus was performed to determine AFL inducibility. A total of 25 patients with sustained (17 patients) or reproducible (eight patients) AFL were included in this study. Patients were randomized to mapping and ablation of AFL using the CARTO 3D mapping system (Biosense Webster, Diamond Bar, CA, USA) versus no further ablation. Typical AFL was induced in 48% of the patients. During a follow‐up of 12 ± 4 months, recurrences were determined by serial 48‐h Holter and event monitors. Recurrence rates, time to recurrence, and AFL cycle length differences between both groups were not statistically significant. Conclusion: These data suggest that inducibility of AFL post PVAI does not predict long‐term incidence of AFL. Moreover, this study demonstrates little benefit to mapping and ablation of these arrhythmias during the PVAI procedures.     

Atrio-Pulmonary Vein Conduction Delay during Pulmonary Vein Isolation for Atrial Fibrillation Is Related to Vein Anatomy, Age, and Focal Activity

Background: During pulmonary vein isolation for treatment of atrial fibrillation (AF), a significant delay in atrio-pulmonary vein (PV) conduction is often observed. We sought to investigate this conduction delay in various PV in individual patients.
Methods: We studied 385 AF patients (mean age: 54 ± 11 years, 74 women) who underwent segmental PV isolation (PVI). A circular decapolar catheter was used to record electrograms at the PV ostia. The time delay from local atrial potential to PV potential was measured in each vein. Conduction delay (CD) was defined as the longest time interval >20 ms observed during PVI.
Results: For patients treated for the first time, CD was more frequently observed in the left common and the right and left superior PVs (84.2%, 67.9%, and 66.2%, respectively) and less frequently in the left and right inferior and right middle PVs (54.3%, 40.0%, and 30.8%, respectively). Veins with CD required more ablation applications (12.4 vs 9.9) and a higher ablated segmental fraction (72.3% vs 63.7%). CD was observed in 75.2% (109/145) of the PVs in which focal activity was detected. Older patients had a higher incidence of PVs with CD than younger patients. There were no gender differences.
Conclusions: The incidence of CD was highest in the left common and superior PVs, in older patients and in PVs with focal activity. PVs with CD required more ablation applications and a larger area of ablation around the ostia. These observations were not found during repeat procedures.     

A Clinical Study of Patients with and Without Recurrence of Paroxysmal Atrial Fibrillation After Pulmonary Vein Isolation

Patients with paroxysmal atrial fibrillation (PAF) can be treated by pulmonary vein (PV) isolation. However, the recurrence rate after this procedure is relatively high. We sought to evaluate the quality of life (QOL) of patients with PAF recurrence after PV isolation and to analyze factors related to recurrences. Seventy-two drug-refractory PAF patients (59 men, 13 women, mean age 52 ± 10) were included. PV isolation was based on the disappearance of PV potentials recorded from a Lasso catheter after segmental ostium ablation. Automatic foci were observed in 47 patients (65.3%) during the procedure. A mean of 3.1 ± 0.9 PVs was isolated. Patients were followed for a mean of 10.3 ± 5.1 months, during which 27 experienced >1 episode of PAF. QOL was scored from 0 (situation before ablation) to 10 (no episode after ablation) based on a questionnaire completed by 69 patients (95.8%). QOL was judged very good in 26 patients (none with PAF recurrences), better in 30 (15 with PAF recurrences), unchanged in 11 (10 with recurrences), and worse in 2 patients with PAF recurrences. Longer histories of PAF and a lower percentage of patients with automatic foci identified during the procedure were observed in the group with, than in the group without recurrences (P < 0.05). PV isolation improved QOL in patients with PAF, including in patients with recurrences. The length of PAF history and observation of automatic foci may be of importance for recurrences of PAF during long-term follow-up.     

Left Phrenic Nerve Injury during Cryoballoon Ablation of the Left Superior Pulmonary Vein

Transcatheter ablation of the pulmonary veins (PVs) has been established as a therapeutic option for patients with symptomatic atrial fibrillation. Cryothermal energy is an alternative energy source that has been developed to overcome some of the disadvantages of radiofrequency ablation. The major complication of the cryoballoon technique seems to be right‐sided phrenic nerve injury (PNI) following ablation of the right superior PV. This case report describes a left‐sided PNI after cryoballoon ablation of the left superior PV. (PACE 2012; 35:e334–e336)     

The Anatomic Impact of Sequential,Additional, Ostial Radiofrequency Ablation Following Pulmonary Vein Cryo‐Isolation

Background : Although pulmonary vein (PV) stenosis is a serious complication of radiofrequency PV isolation, the anatomical impact of a combination of two energy sources on PV diameter has not been evaluated. The aim of this study was to evaluate the impact of supplementary point‐by‐point radiofrequency applications (following PV cryoablation) on the PV orifice diameter. Methods : Forty‐nine patients having undergone PV isolation for drug‐refractory atrial fibrillation were included. All had undergone cardiac computed tomography before ablation and again at least 3 months afterwards. When isolation with the cryoballoon was not complete, a conventional irrigated‐tip radiofrequency catheter was used for point‐by‐point applications. Results : Of the 189 target PVs, 117 were isolated with cryotherapy alone (cryo PVs) and 72 required additional radiofrequency (hybrid PVs). The second scan (performed an average of 11.4 ± 5.4 months after) showed a decrease in diameter for all the hybrid PVs (17.2 ± 2.6 to 16.3 ± 3.4 mm; P = 0.037) but no change for the cryo PVs. This change was associated with a decrease in left superior pulmonary vein (LSPV) diameter (19.2 ± 3.0 to 17.8 ± 4.9 mm, P = 0.014). There were no changes in other veins. A subgroup analysis for the LSPV revealed a decrease for the hybrid PVs (18.8 ± 3.6 to 15.9 ± 7.1 mm, P = 0.046) but not for the cryo PVs. Significant PV stenosis was observed in three hybrid PVs (two severe stenosis of the LSPV and one moderate stenosis of the right inferior pulmonary vein) but not in cryo PVs (4.1% vs 0%, respectively; P = 0.023). Conclusions : Cryoballoon ablation of the PV with adjunct, focal, irrigated ostial RF applications may be associated with a higher risk of PV stenosis. (PACE 2012;35:1420–1427)     

Role of Pulmonary Veins Isolation in Persistent Atrial Fibrillation Ablation:

Background: The role of pulmonary veins (PV) isolation in patients with persistent atrial fibrillation (AF) is still debated. The aim of this study was to evaluate the adjunctive role of PV isolation in patients with persistent AF who underwent circumferential PV ablation (anatomical approach).
Methods: We treated 97 consecutive patients presenting with drug-refractory persistent AF by an anatomical approach (group A, n = 36, mean age = 60 ± 8 years, 29 males) or an integrated approach (group B, n = 61, mean age 59 ± 10 years, 48 males). In all patients, radiofrequency (RF) ablation was performed by means of a nonfluoroscopic navigation system, in order to anatomically create circumferential lines around the PV. In group B, the persistence of PV potentials was ascertained with a multipolar circular catheter. If PV potentials persisted, RF energy targeting the electrophysiological breakthroughs was delivered to disconnect the PV. Past a 2-month period of observation, success was defined as absence of any atrial tachyarrhythmia recurrence lasting >30 seconds.
Results: Total procedure duration (220 ± 62 minutes vs 140 ± 43 minutes, P < 0.001), fluoroscopy time (35 ± 15 minutes vs 17 ± 9 minutes, P < 0.001), and RF delivery time (48 ± 22 minutes vs 27 ± 9 minutes, P < 0.001) were significantly longer in group B than in group A. One cardiac perforation occurred in group A. After 15 ± 9.1 months, 21 patients in group A (58%) and 34 patients in group B (56%) were free of atrial tachyarrhythmia recurrence (P = 0.9).
Conclusions: In patients with persistent AF, who underwent an anatomical approach, electrophysiological confirmation of PV disconnection significantly increased the fluoroscopy and procedural times, without effect on the long-term outcomes.     

Significance of Late Recurrence of Atrial Fibrillation during Long-Term Follow-Up after Pulmonary Vein Isolation

Background and Study Objective : Patients with paroxysmal or persistent atrial fibrillation (AF) can be treated by pulmonary vein (PV) isolation. Although the recurrence rate after the procedure is relatively high, the long-term outcomes after initially recurrence-free procedures remains unclear. We examined the rates of recurrence of AF after PV isolation.
Methods: Our study included 278 consecutive patients with drug-refractory AF (mean age = 53 ± 11 years, 228 men). PV isolation was based on the disappearance of PV potentials recorded from a circumferential catheter after segmental ostium ablation. Cavo-tricuspid isthmus lines and additional atrial lines were performed in 124 and 28 patients, respectively. Patients were monitored for a mean of 26 ± 11 months (range 12–56). Recurrence was defined as ≥1 episodes of symptomatic or asymptomatic AF >1 month after the procedure.
Results: A total of 120 (34) patients had ≥1 recurrence of AF >1 month after the procedure, of whom 14 (4) had a first recurrence >6 months after the procedure. There was a significantly higher recurrence rate among patients with persistent AF.
Conclusions : A relatively high AF recurrence rate was observed after PV isolation. AF may recur late after the ablation procedure, though the majority of recurrences occurred within 6 months after the first procedure. There were no differences in incidence or time of occurrence of late recurrences between patients with paroxysmal versus persistent AF.