Circular Mapping Catheter Research Articles

Radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique: 4-year follow-up

Abstract Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. Cryoablation has been shown to be a safe and effective technique for pulmonary vein isolation. However, there is a significant arrhythmia recurrence rate after cryoablation procedures and there are no established strategies for redo procedures in these patients. Therefore, we have summarized our experience with radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique (including an analysis of pulmonary vein conduction recovery patterns ater procedures performed with the first or second generation cryoballoon). Methods One hundred and fifty patients (paroxysmal AF: 99 patients, persistent AF: 51 patients) had to undergo a redo procedure after initially successful circumferential PV isolation with the cryoballoon technique (Arctic Front Balloon: 75 patients (group A); Arctic Front Advance: 75 patients (group B)). The redo ablation procedures were performed using a segmental approach or a circumferential ablation strategy (CARTO) depending on the intra-procedural findings. Results During the redo procedure, a mean number of 1.7 re-conducting PVs were detected (using a circular mapping catheter; group A: 2.1 re-conducting PVs, group B: 1.3 re-conducting PVs). There was a slightly higher incidence of chronic PV reconnections related to the left-sided PV ostia than to the right-sided PVs in both groups. Furthermore, sites of chronic PV reconnection were found more frequently in the inferior parts of the PV ostia than in the superior parts. In 65 patients in group A, a segmental approach was sufficient to eliminate the residual PV conduction because there were only a few recovered PV fibers (1–3 reconnected PVs; group A1). In the remaining 10 patients in group A, a circumferential ablation strategy was used because of a complete recovery of the PV-LA conduction of all four pulmonary veins (group A2). In group B, a segmental approach was sufficient in all patients because there was only a minor reconnection of 1–2 PVs. All recovered PVs could be isolated sucessfully again. At 48-month follow-up, 74.7% of all patients were free from an arrhythmia recurrence (112/150 patients; group A: 51/75 patients (68%), group B: 61/75 patients (81.3%)). There were no major complications in both groups. Conclusions In patients with an initial circumferential PVI using the cryoballoon technique, a repeat ablation procedure can be performed safely and effectively using radiofrequency catheter ablation. In most cases only a few re-conducting PV fibers were found and therefore, a segmental re-ablation approach seems to be sufficient in the majority of patients (especially in patients treated with the second generation cryoballoon). Funding Acknowledgement Type of funding source: None

Novel occlusion tool software for pulmonary vein occlusion verification in atrial fibrillation cryoballoon ablation

Abstract Background Optimal pulmonary vein (PV) occlusion, checked with selective contrast injection, is mandatory to obtain an effective PV isolation with a cryoballoon. Purpose The purpose of this study was to verify the feasibility of a new dielectric sensing system in assessing PV occlusion during cryoballoon ablation in patients with atrial fibrillation (AF). Methods We enrolled 25 consecutive patients with paroxysmal or persistent AF. After transseptal access a detailed image reconstruction of left atrium and PVs was achieved with a decapolar circular mapping catheter and a novel dielectric imaging system. The degree of PV occlusion with the inflated cryoballoon catheter was verified by a new occlusion tool software of the dielectric imaging system and compared to the angiography with dye injection in each PV. Results A total of 114 PV cryoballoon occlusion were tested. The new occlusion tool software showed a 91.7% sensitivity and 81.5% specificity in assessing a complete PV occlusion verified with dye injection. The positive predictive value was 84.6% and the negative predictive value was 89.8%. Acute isolation was achieved in all PVs. No 30 days complications were observed. Conclusion This is the first study that demonstrates the feasibility of a new occlusion tool software, using the novel dielectric imaging system, in verifying the degree of PV occlusion during cryoballoon ablation. Funding Acknowledgement Type of funding source: None

Near zero fluoroscopy cryoballoon catheter ablation in patients with atrial fibrillation using a novel dielectric imaging system

Abstract Background Fluoroscopy is commonly used in cryoballoon catheter ablation for pulmonary vein (PV) isolation procedures in patients with atrial fibrillation (AF). Purpose The purpose of this study was to verify the feasibility of a new dielectric imaging system in reducing the radiation exposure during cryoballoon ablation in patients with AF. Methods We enrolled 40 consecutive patients with paroxysmal AF: 20 patients underwent the procedure under fluoroscopy guidance before the new system introduction, while 20 patient underwent the procedure under fluoroscopy and a new dielectric imaging system guidance with its occlusion tool software. After transseptal access a detailed image reconstruction of left atrium and PVs was achieved with an octapolar circular mapping catheter and the cryoablation was performed with a cryoballoon catheter. Results Total time of the procedure was comparable between the two groups (90.15±28.67 vs 80.77±17.17 using the dielectric imaging system, p=0.34), while fluoroscopy time was significantly lower in the group using the new dielectric imaging system (16.92±8.96 vs 5.54±2.06, p<0.01). Acute isolation was achieved in all PVs. No 30 days complication was observed. Conclusion This is the first study that demonstrates the feasibility of a reduce fluoroscopy workflow using the novel dielectric imaging system in a cryoballoon procedure. Funding Acknowledgement Type of funding source: None

Reduction of mapping time in pulmonary vein isolation using atrial pacing during left atrial voltage map acquisition

Introduction3D mapping systems are used during radiofrequency (RF) pulmonary vein isolation (PVI) to facilitate catheter navigation and to provide additional electroanatomical information as a surrogate marker for the presence and location of fibrotic atrial myocardium.Electric voltage information can only be measured when the myocardium is depolarized. Low heart rates or frequent premature atrial beats can significantly prolong creation of detailed left atrial voltage maps. This study was designed to evaluate the potential advantage of voltage information collection during atrial pacing instead of acquisition during sinus rhythm. Methods and resultsA total of 40 patients were included in the study, in 20 consecutive patients voltage mapping was performed during sinus rhythm, and in the following 20 patients during atrial pacing. The average age of the included patients was 69.5 ± 9.4, 17 of 40 patients (43%) were male.All procedures were performed using the Carto 3D Mapping system. For LA voltage mapping, a multipolar circular mapping catheter was used. The atrium was paced via the proximal coronary sinus catheter electrodes with a fixed cycle length of 600 ms.By mapping during atrial pacing mapping time was reduced by 35% (441 s. (±141) vs.683 s. (±203) p = 0.029) while a higher number of total mapping points were acquired (908 ± 560 vs. 581 ± 150, p = 0.008). ConclusionAcquiring left atrial low voltage maps during atrial pacing significantly reduces mapping time. As pacing also improves comparability of left atrial electroanatomical maps we suggest that this approach may be considered as a standard during these procedures.

A circular mapping catheter is not mandatory for isolating pulmonary veins during paroxysmal atrial fibrillation ablation with radiofrequency.

In this study, we evaluated the feasibility, efficacy, and safety of radiofrequency ablation of paroxysmal atrial fibrillation (AF) with the use of an ablation catheter only (non-CMC group) by retrospectively comparing its procedural success and recurrence rates at 1year to ablation performed with the help of a circular mapping catheter (CMC group). We compared the success and recurrence rates between 226 patients and 251 patients who underwent index ablation with and without the use of CMC, respectively. Freedom from recurrence was defined as a 1-year absence of AF/atrial tachycardia (AT) episodes > 30s, beyond the 3-month blanking period. There was no significant difference between the number of pulmonary vein isolations, recurrence rate of AF/AT, and the use of antiarrhythmic drugs after 1year of ablation. The procedure and fluoroscopy times were lower in the non-CMC group compared with the CMC group (106 ± 33 vs. 125 ± 32min, p < 0.0001; 2.2 ± 1.9 vs. 2.7 ± 2.3min, p = 0.0002, respectively). Pulmonary vein isolation without the use of a CMC is feasible; moreover, the material costs, procedure time, and radiation exposure were reduced compared with the CMC group. Freedom of recurrence was similar between groups. Optimized use of 3D electro-anatomical mapping systems could reduce the radiation exposure for both the patient and physician.

Pulmonary Vein Isolation With Single Pulse Irreversible Electroporation: A First in Human Study in 10 Patients With Atrial Fibrillation.

Irreversible electroporation (IRE) is a promising new nonthermal ablation technology for pulmonary vein (PV) isolation in patients with atrial fibrillation. Experimental data suggest that IRE ablation produces large enough lesions without the risk of PV stenosis, artery, nerve, or esophageal damage. This study aimed to investigate the feasibility and safety of single pulse IRE PV isolation in patients with atrial fibrillation. Ten patients with symptomatic paroxysmal or persistent atrial fibrillation underwent single pulse IRE PV isolation under general anesthesia. Three-dimensional reconstruction and electroanatomical voltage mapping (EnSite Precision, Abbott) of left atrium and PVs were performed using a conventional circular mapping catheter. PV isolation was performed by delivering nonarcing, nonbarotraumatic 6 ms, 200 J direct current IRE applications via a custom nondeflectable 14-polar circular IRE ablation catheter with a variable hoop diameter (16-27 mm). A deflectable sheath (Agilis, Abbott) was used to maneuver the ablation catheter. A minimum of 2 IRE applications with slightly different catheter positions were delivered per vein to achieve circular tissue contact, even if PV potentials were abolished after the first application. Bidirectional PV isolation was confirmed with the circular mapping catheter and a post ablation voltage map. After a 30-minute waiting period, adenosine testing (30 mg) was used to reveal dormant PV conduction. All 40 PVs could be successfully isolated with a mean of 2.4±0.4 IRE applications per PV. Mean delivered peak voltage and peak current were 2154±59 V and 33.9±1.6 A, respectively. No PV reconnections occurred during the waiting period and adenosine testing. No periprocedural complications were observed. In the 10 patients of this first-in-human study, acute bidirectional electrical PV isolation could be achieved safely by single pulse IRE ablation.

The feasibility and effectiveness of a streamlined single-catheter approach for radiofrequency atrial fibrillation ablation.

BackgroundCatheter ablation for atrial fibrillation (AF) traditionally requires the use of circular mapping catheter (CMC) for pulmonary vein isolation (PVI). This study aimed to assess the feasibility and effectiveness of a CMC‐free approach for AF ablation performed by a contiguous optimized (CLOSE) ablation protocol.MethodsA CLOSE‐guided and CMC‐free PVI protocol with a single transseptal puncture was attempted in 67 patients with AF. Left atrial (LA) CARTO voltage mapping was performed with the ablation catheter pre‐ and postablation to demonstrate entry block into the pulmonary veins, and pacing maneuvers were used to confirm exit block.ResultsThe CMC‐free approach was successful in achieving PVI in 66 (98.5%) cases, with procedure time of 148 ± 32 minutes, ablation time of 27.5 ± 5.7 minutes, and fluoroscopy time of 7.8 ± 1.0 minutes. First‐pass PVI was seen in 58(86.5%) patients, and pacing maneuvers successfully identified the residual gap in eight of the other nine cases. No complication was observed. At 12 months follow‐up, 60 (89.6%) patients remained free from AF. The CMC‐free approach resulted in a cost saving of £47,190.ConclusionA CMC‐free CLOSE‐guided PVI approach is feasible, safe, and cost‐saving, and is associated with excellent clinical outcomes at 1 year.

P1061Incidence and location of PVI gaps identified post-cryoballoon ablation for atrial fibrillation

Abstract Background Successful delivery of continuous and durable pulmonary vein isolation (PVI) lesion sets is recognized as being critical to long-term clinical outcomes following ablation for atrial fibrillation (AF). Confirmation of PVI following cryoballoon ablation is commonly achieved using a 3.3F circular mapping catheter (CMC) which can be delivered through the central lumen of the cryoballoon, but other diagnostic tools may be used alone or in conjunction with the 3.3F CMC. A high-density, grid-style mapping catheter is now available in multiple geographies; use in cryoballoon ablation procedures and associated outcomes has not been previously reported. Purpose To evaluate diagnostic catheter usage patterns in cryoablation procedures and identify associated trends in procedural characteristics and acute outcomes. Methods Self-reported procedural data was prospectively collected in AF cryoablation cases utilizing various diagnostic catheter tools, including the 3.3F CMC and high-density, grid-style mapping catheter (HD Grid). Procedural characteristics and acute outcomes, including the incidence and location of gaps post-ablation, were recorded and analyzed. Results Data was collected in 23 cryoablation procedures performed in 7 centers across the United States and Europe. De novo and repeat ablations represented 65.2% and 21.7% of cases, respectively (13.0% not reported). 3D mapping was employed in 95.7% of cases. A left common pulmonary vein was present and ablated in 8.7% (2/23). The 28mm cryoballoon was utilized in all cases, with a single case using both a 23mm and 28mm cryoballoon. The 3.3F CMC was used to confirm isolation in all cases using a variety of techniques: voltage mapping (60.9%), exit block (56.5%), entrance block (30.4%), propagation mapping (4.3%), and activation mapping (4.3%); note: total exceeds 100% as more than one technique may be employed in a single case. In 18 cases, PVI was confirmed using a 3.3F CMC followed by secondary confirmation with HD Grid, enabling a direct comparison of the two technologies. The HD Grid identified a total of 12 gaps in 4 (22.2%) patients, which were missed by the 3.3F CMC (Figure 1). No adenosine or isoproterenol use was documented in any case. Conclusion(s): The 3.3F CMC is routinely used to confirm PVI following cryoballoon ablation for atrial fibrillation, but it may fail to identify gaps in some patients. Subsequent assessment of PVI using the HD Grid identified residual gaps in nearly a quarter of patients, suggesting that sensitivity for gap detection may be improved with this tool. Limitations of this analysis include the small sample size and workflows which consistently assessed PVI with the high-density mapping catheter after confirming isolation with the 3.3F CMC. Despite these limitations, the incidence of residual gaps observed is noteworthy and may warrant additional study. Abstract Figure.

P1382Extended long-term follow-up of radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique (first versus second generation cryoballoon)

Abstract Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. Cryoablation has been shown to be a safe and effective technique for pulmonary vein isolation. However, there is a significant arrhythmia recurrence rate after cryoablation procedures and there are no established strategies for redo procedures in these patients. Therefore, we have summarized our experience with radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique (including an analysis of pulmonary vein conduction recovery patterns ater procedures performed with the first or second generation cryoballoon). Methods One hundred and twenty patients (paroxysmal AF: 78 patients, persistent AF: 42 patients) had to undergo a redo procedure after initially successful circumferential PV isolation with the cryoballoon technique. The redo ablation procedures were performed using a segmental approach or a circumferential ablation strategy depending on the intra-procedural findings. Results During the redo procedure, a mean number of 1.8 re-conducting PVs were detected (using a circular mapping catheter; group A: 2.1 re-conducting PVs, group B: 1.5 re-conducting PVs). There was a slightly higher incidence of chronic PV reconnections related to the left-sided PV ostia than to the right-sided PVs in both groups. Furthermore, sites of chronic PV reconnection were found more frequently in the inferior parts of the PV ostia than in the superior parts. In 53 patients in group A, a segmental approach was sufficient to eliminate the residual PV conduction because there were only a few recovered PV fibers (1-3 reconnected PVs; group A1). In the remaining 7 patients in group A, a circumferential ablation strategy was used because of a complete recovery of the PV-LA conduction of all four pulmonary veins (group A2). In group B, a segmental approach was sufficient in all patients because there was only a minor reconnection of 1-2 PVs. All recovered PVs could be isolated sucessfully again. At 42-month follow-up, 78 % of all patients were free from an arrhythmia recurrence (94/120 patients; group A: 43/60 patients (71 %), group B: 51/60 patients (85 %)). There were no major complications in both groups. Conclusions In patients with an initial circumferential PVI using the cryoballoon technique, a repeat ablation procedure can be performed safely and effectively using radiofrequency catheter ablation. In most cases only a few re-conducting PV fibers were found and therefore, a segmental re-ablation approach seems to be sufficient in the majority of patients (especially in patients treated with the second generation cryoballoon).

P1023Comparison of gap identification using three technologies for confirmation of pulmonary vein isolation

Abstract Background Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Tools and techniques used for confirmation of PVI vary greatly, and it is unclear whether the use of any particular combination of tools and techniques provides greater sensitivity for identifying gaps periprocedurally. A high-density mapping catheter enabling simultaneous recording of adjacent bipolar EGMs in two directions is now available in multiple geographies, and it has been suggested that this technology may provide improved sensitivity for gap identification. Purpose To identify trends in the incidence of gaps identified in de novo PVI lines using three diagnostic catheter technologies, which may be suggestive of improved sensitivity for gap identification. Methods Self-reported procedural data was prospectively collected in de novo atrial fibrillation ablation cases utilizing one of three technologies to confirm PVI: 10-pole circular mapping catheter (CMC10), 20-pole circular mapping catheter (CMC20), and Advisor HD Grid catheter (HD Grid). Techniques for PVI confirmation were analyzed for each group, and the incidence and location of gaps identified by each technology was quantified. Results Data was collected in 99 cases across 11 centers in Europe and the United States. PVI was confirmed via entrance and/or exit block in all cases. CMC10 was utilized in 30 cases, CMC20 in 36, and HD Grid in 33. Use of adenosine varied across groups (CMC10: 6.7%; CMC20: 86.1%; HD Grid: 41.7%), as did application of a waiting period (CMC10: 96.7%; CMC20: 2.8%; HD Grid: 11.1%). Gaps were identified in in 36.7%, 38.9%, and 81.8% of cases using CMC10, CMC20, and HD Grid, respectively. HD Grid identified significantly more gaps than the other two technologies (p = 0.015), identifying an average of 49.0% and 139.1% more gaps per patient than CMC20 and CMC10, respectively (HD Grid: 2.15/patient; CMC20: 1.44/patient; CMC10: 0.9/patient). The location and incidence of gaps identified by each technology is shown in Figure 1. Conclusions Significantly more gaps were identified by the Advisor HD Grid catheter, as compared to a 10-pole or 20-pole circular mapping catheter. While this does not represent a direct comparison of the sensitivity for identification of gaps across these three technologies, and results could be impacted by other factors (e.g., operator, ablation technique, PVI confirmation technique, etc.), the strong trend toward an increased number of gaps identified with the HD Grid is striking. This may warrant further study including direct comparison of gap identification across technologies, and the resulting impact on long-term clinical outcomes when these additional gaps are ablated during the index procedure. Abstract Figure.

Confirmation of Pulmonary Vein Isolation with High-Density Mapping: Comparison to Traditional Workflows.

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Yet tools and techniques used for confirmation of PVI vary greatly, and it is unclear whether the use of any particular combination of tools and techniques provides greater sensitivity for identifying gaps periprocedurally. It has been suggested the use of a high-density mapping catheter, which enables simultaneous recording of adjacent bipolar EGMs in two directions, may provide improved sensitivity for gap identification. Anonymized, acute procedural data was prospectively collected in AF ablation cases utilizing various workflows for confirmation of PVI. Post-hoc analysis was performed to evaluate the incidence of gaps detected by different diagnostic catheter technologies, including a high-density mapping catheter and circular mapping catheters (CMCs), and common techniques such as pacing the ablation lines. A total of 139 cases were included across three subgroup analyses: 99 cases were included in an indirect comparison of three mapping catheter technologies, revealing gaps in 36.7%, 38.9%, and 81.8% of cases utilizing a 10-pole CMC, 20-pole CMC, and a high-density mapping catheter, respectively; a direct comparison of diagnostic catheter technologies in 18 cryoballoon ablation cases revealed residual gaps in 22.2% of patients identified by high-density mapping which were missed previously with the use of a 3.3F CMC; in 22 cases utilizing a technique of pacing the ablation lines, high-density mapping identified residual gaps in 68.2% of patients. This proof of concept analysis demonstrated that the use of a high-density catheter which records orthogonal bipoles simultaneously, appears to improve acute detection of gaps in PVI lines relative to other commonly utilized techniques and technologies. The long-term impact of ablating these concealed gaps remains unclear. Further study, including direct comparison of diagnostic catheter technologies in a randomized setting with long-term followup, is warranted.

Cryoablation for atrial fibrillation.

Cryoballoon ablation for the treatment of atrial fibrillation has established itself as an effective and efficient modality for achieving pulmonary vein isolation. Over the past 13 years more than 100,000 Cryoballoon ablation procedures have been performed with the first to fourth generation cryoballoons. Over that time there have been significant advances in our understanding regarding the optimal procedural techniques. The purpose of this "topic in review" is to focus on the practical aspects of performing a Cryoballoon ablation procedure, within the context of the contemporary literature. Specifically there is a focus on how contemporary studies can inform clinical decision making and ensure operators are able to perform a safe and effective procedure.

2019 APHRS expert consensus statement on three-dimensional mapping systems for tachycardia developed in collaboration with HRS, EHRA, and LAHRS.

2019 APHRS expert consensus statement on three-dimensional mapping systems for tachycardia developed in collaboration with HRS, EHRA, and LAHRS.

Association of Left Atrial Appendage Voltage with Ischemic Stroke in Patients with Atrial Fibrillation.

Low atrial voltage is associated with an increased risk of stroke. The relationship between left atrial appendage voltage (LAAV) and ischemic stroke remains unknown. Low LAAV may predict the prevalence of ischemic stroke in patients with atrial fibrillation (AF). A total of 1108 patients with AF referred for catheter ablation were consecutively included from January 2015 to May 2018. The patients were divided into stroke and control groups based on previous ischemic stroke by neuroimaging criteria. LAAV was measured with a circular mapping catheter in sinus rhythm after ablation. Variables were compared, and logistic regression was performed to assess the relationship between LAAV and stroke. A total of 120 patients (10.8%) had a history of ischemic stroke. The patients in the stroke group were older and had higher percentages of hypertension, diabetes mellitus and coronary/vascular disease. The CHA2DS2-VASc score was higher and left atrial diameter was larger in the patients with stroke. More left atrial appendage thrombi and spontaneous echo contrast were detected in the stroke group. LAAV was significantly lower in the stroke group compared with the controls (5.3 ± 1.8 mV vs. 6.5 ± 1.8 mV; p < 0.001). Multivariate logistic regression revealed that a lower LAAV was associated with increased stroke prevalence [odds ratio = 0.75; 95% confidence interval (CI) 0.65-0.87; p < 0.001]. LAAV had a predictive value, with an area under the curve of 0.83 (95% CI 0.79-0.87; p < 0.001). With an optimal cut-off value of 5.2 mV for LAAV, the sensitivity and specificity were 75% and 74%, respectively. Lower LAAV in AF patients was associated with increased ischemic stroke prevalence. Whether LAAV is related to incident stroke requires further studies.

P2849Prevalence and significance of sustained pulmonary vein isolation in repeat AF ablation procedures

Abstract Introduction Pulmonary vein (PV) reconnection is a common cause of relapse after catheter ablation of atrial fibrillation (AF). However, some patients have AF recurrence despite durable PV isolation. The aim of this study was to assess the PV isolation status at the time of a second catheter ablation (redo) procedure, and its relationship with subsequent AF relapse. Methods Consecutive patients with symptomatic drug-resistant AF who underwent redo procedures from January 2006 to December 2017 were identified in a single-center observational registry. Pulmonary vein isolation status was assessed during the electrophysiologic study with a circular mapping catheter. Additional radiofrequency (RF) energy applications were also recorded. AF relapse was defined as symptomatic or documented AF/atrial tachycardia/atrial flutter after a 3-month blanking period. Results We identified 240 patients (77 [32%] females, median age 61 [IQR 53–67] years, 85 [35%] with non-paroxysmal AF) undergoing redo procedures during the study period. At the time of redo, 17 (7%) of the patients presented bidirectional conduction block of all PVs. PV reconnection occurred in 157 (65%) of cases in the left superior vein, 142 (59%) in the left inferior vein, 177 (73%) in the right superior vein, and 163 (68%) in the right inferior vein (table). All of the PVs were reconducted in 91 (38%) patients. Additional RF applications were performed in the left atrium (LA) roof, LA posterior wall, cavotricuspid isthmus, mitral isthmus, superior vena cava, coronary sinus, and left atrial appendage ostium, at the operator's discretion (table 1). Over a median follow-up of 2-years (IQR 1–5), 126 patients (53%) suffered AF recurrence, yielding a mean relapse rate of 17%/year. In multivariate Cox regression analysis, the lack of PV reconnection at the time of redo emerged as an independent predictor of subsequent relapse (HR 1.97, 95% CI 1.12–3.49, p=0.019) even after adjustment for univariate predictors including non-paroxysmal AF, body mass index, female sex, and active smoking. Conclusion In patients undergoing redo AF ablation procedures, less than 10% present with complete PV isolation. Despite being relatively infrequent, this finding is independently associated with greater likelihood of subsequent recurrence, suggesting that other mechanisms, not fully addressed by additional RF applications, are at play.

A decapolar 25-mm-diameter circular mapping catheter with improved detection of pulmonary vein potential disappearance in cryoballoon ablation.

BackgroundDisappearance of pulmonary vein (PV) potentials is an important indicator of successful PV isolation during cryoballoon ablation. Conventional octapolar 20‐mm‐diameter circular PV mapping catheters occasionally fail to identify persistent PV potentials. A new decapolar 25‐mm‐diameter circular PV mapping catheter has been introduced to improve the detection of PV potentials and their elimination. We compared the detection rates of PV potential disappearance between the decapolar and the octapolar PV mapping catheters.Methods and ResultsA total of 44 consecutive patients (175 PVs) undergoing initial cryoballoon ablation for atrial fibrillation were included. The decapolar catheter was used for 79 (45%) PVs in 20 (45%) patients. There was no difference in left atrial diameter or PV diameter in patients mapped with the two catheters. The decapolar mapping catheter demonstrated a significantly higher detection rate of PV potential disappearance than the octapolar catheter. The need for touch‐up ablation was similar between the two groups (5% vs 8%, P = 0.39). When PV potentials were identified, the decapolar catheter detected significantly higher‐amplitude PV potentials than the octapolar catheter. In multivariate analysis, use of the decapolar catheter was an independent predictor of the detection of PV potential disappearance.ConclusionsThe decapolar PV mapping catheter demonstrated improved detection of PV potential disappearance in cryoballoon PV isolation.

Touch-up and recurrence rates after voltage mapping for verification of pulmonary vein isolation following cryoablation of paroxysmal atrial fibrillation

The procedural endpoint following cryoballoon ablation (CA) for paroxysmal atrial fibrillation (PAF) is pulmonary vein isolation (PVI), which is typically confirmed by entrance/exit block using a circular mapping catheter. The present study added an assessment of ablation gaps with high-density voltage mapping after standard confirmation of PVI. Relationships between the need for touch-up ablation, patient characteristics, and atrial arrhythmia recurrence were explored. PAF patients received CA through standard of care treatment, with PVI assessed by bidirectional block confirmation, followed by voltage mapping. Radiofrequency ablation was performed as needed for voltage breakthrough and or additional rhythms. Freedom from atrial arrhythmia recurrence through 12-month follow-up was analyzed retrospectively with statistical survival models. A total of 77 PAF patients (age 66.1 ± 11.6, CHADS2 1.8 ± 1.0) were followed for 1.2 ± 0.3years after CA. During the index procedure, pulmonary vein (PV) touch-up was required in 59 patients (76.6%) and ablation of additional atrial fibrillation targets beyond PV was required in 26 patients (33.8%). Kaplan-Meier estimates of freedom from atrial arrhythmia recurrence at 1year were 62 ± 6%. Rates were lower for patients requiring touch-up ablation (58 ± 6% vs. 78 ± 10%) or with CHADS2 scores > 2 (33 ± 12% vs. 69 ± 6%). Cox regression models showed that the need for touch-up ablation increased recurrence (p = .045, HR = 2.6) after adjusting for hypertension and heart failure. The high rate of PV touch-up suggests that initial CA lesions may be less durable than previously assumed, while the higher recurrence rate in patients requiring touch-up may indicate that additional factors make these patients more difficult to treat.

Characterization of pulmonary vein reconnection post Cryoballoon ablation

BackgroundThe Arctic Front Cryoballoon System is a technology in which substrate alterations in patients with atrial fibrillation (AF) recurrence have not been well characterized. In this study, we evaluated sites of pulmonary vein (PV) reconnections and the accuracy of the Achieve™ circular mapping catheter in detecting these reconnections after cryoablation. MethodsThis study included 15 patients undergoing redo AF ablation after a prior single cryoablation procedure. PV reconnection sites were determined by measuring PV signals and high output pacing from 4 vectors of the Achieve catheter. The results were compared with a roving mapping catheter guided by rotational intracardiac echocardiography (ICE) in the left atrium. ResultsAll patients had PV reconnections (2.1 ± 0.8 veins/patient). The left superior PV was most commonly reconnected (n = 11), whereas the right inferior PV was least likely (n = 3). Both carinas (left: n = 11; right: n = 7) and left atrial appendage ridge (n = 11) were also frequently reconnected. Mapping with the Achieve catheter showed a positive predictive value (PPV) 100% and negative predictive value (NPV) 96% when compared with ICE guided mapping. In 2 patients, right superior PV reconnection was not identified by the Achieve. ConclusionDuring redo AF ablation after index cryoablation, multiple PVs are usually reconnected, with both carinas and left atrial appendage ridge being common sites of reconnection. The Achieve mapping catheter was able to identify reconnection with high positive and negative predictive values.

Predictors of long-term outcome in patients undergoing a first repeat ablation consisting solely of re-isolation of reconnected pulmonary veins.

To define predictors of long-term outcome of a first repeat ablation solely consisting of re-isolation of reconnected pulmonary veins (PVs). 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. 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. 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.

Remanufactured circular mapping catheters: safety, effectiveness and cost

BackgroundThe use of remanufactured single-use devices (SUDs), including cardiac electrophysiology catheters, has become established in the USA and other health care systems but without much published scientific evaluation on the relative safety or efficacy of these devices. In the United Kingdom (UK), the use of remanufactured SUDs has not been routine. We performed a structured evaluation of the safety and efficacy of a remanufactured circular mapping catheter (Stryker® remanufactured Lasso NAV 2515) during its introduction in our centre.MethodsWe prospectively evaluated the performance of a remanufactured circular mapping catheter in 100 consecutive patients undergoing an AF ablation. Operator feedback was obtained, assessing the device appearance, ease of use and function. As an indirect measurement of efficacy, acute procedure metrics were compared to those in 100 propensity-matched cases performed by the same operators using a new device. Cost savings were calculated.ResultsNo complication occurred in association with the remanufactured device. There was one reported failure of device malfunction—the flexion-extension mechanism of a remanufactured catheter and none in the matched-control group. There was satisfactory communication with the electro-anatomic mapping system. Ease of use of the remanufactured catheter was reported to be similar to a newly manufactured device. Procedural duration was similar with remanufactured devices and matched controls. With 100 cases using the remanufactured device, cost savings amounted to £30,444.ConclusionsThe use of remanufactured circular mapping catheters is safe, efficient and reliable. Widespread use of remanufactured SUDs offers the possibility of significant economic benefit.