Impact of deep sedation on the electrophysiological behavior of pulmonary vein and non-PV firing during catheter ablation for atrial fibrillation

The importance of anaesthesia in atrial fibrillation ablation: Comparing conscious sedation with general anaesthesia

BACKGROUND

General anaesthesia (GA) for atrial fibrillation (AF) ablation is often preferred over conscious sedation (CS) to minimize patient discomfort and reduce the risk of map disruption from patient movement but may pose an additional risk to some patients with significant comorbidity or poor cardiac function.

METHODS

We extracted data for 300 patients who underwent AF ablation between the years 2017 and 2019 and compared the outcomes of AF ablation with CS and GA.

RESULTS

Compared to the GA group, patients were younger in the CS group (63 versus 66 years, p = 0.02), had less persistent AF (34% versus 46%, p = 0.048) and the left atrial dimension was smaller (41 versus 45 mm, p = 0.01). More patients had cryoballoon ablation (CBA) than radiofrequency (RFA) ablation in the CS than the GA group (88% CB with CS and 56% RF with GA, p < 0.01), frequency of ASA score 3-4 (higher anaesthetic risk) was less for CS than for GA (45% versus 75%, p < 0.01), and procedural duration was shorter for patients who had CS (110 versus 139 min, p < 0.001). Of the patients receiving CS, 127/182 (70%) were planned for same day discharge (SDD) and this occurred in 120 (94%) of those patients. There were no significant differences in complication rates between the groups (5.1% in GA and 6% in CS, p = 0.8). AF type was the only significant predictor of freedom from AF recurrence on multivariate analysis (HR 0.33, 0.13-0.82, p = 0.018).

CONCLUSION

In this study, the use of CS compared with GA for AF ablation was associated with similar outcomes and complication rates.

Intra-atrial activation pattern is useful to localize the areas of non-pulmonary vein triggers of atrial fibrillation

Background

Pulmonary vein isolation (PVI) is an established ablation procedure for atrial fibrillation (AF), however, PVI alone is insufficient to suppress AF recurrence. Non-pulmonary vein (non-PV) trigger ablation is one of the promising strategies beyond PVI and has been shown to be effective in refractory/persistent AF cases. To make non-PV trigger ablation more standardized, it is essential to develop a simple method to localize the origin of non-PV triggers.

Methods

We retrospectively analyzed 37 non-PV triggers in 751 ablation sessions for symptomatic AF from January 2017 to December 2020. Regarding non-PV triggers, intra-atrial activation interval from the earliest in right atrium (RA) to proximal coronary sinus (CS) (RA-CSp) and that from the earliest in RA to distal CS (RA-CSd) obtained by a basically-positioned duodecapolar RA-CS catheter were compared among 3 originating non-PV areas [RA, atrial septum (SEP) and left atrium (LA)].

Results

RA-CSp of RA non-PV trigger (56.4 ± 23.4 ms) was significantly longer than that of SEP non-PV (14.8 ± 25.6 ms, p = 0.019) and LA non-PV (-24.9 ± 27.9 ms, p = 0.0004). RA-CSd of RA non-PV (75.9 ± 32.1 ms) was significantly longer than that of SEP non-PV (34.2 ± 32.6 ms, p = 0.040) and LA non-PV (-13.3 ± 41.2 ms, p = 0.0008). RA-CSp and RA-CSd of SEP non-PV were significantly longer than those of LA non-PV (p = 0.022 and p = 0.016, respectively). Sensitivity and specificity of an algorithm to differentiate the area of non-PV trigger using RA-CSp (cut-off value: 50 ms) and RA-CSd (cut-off value: 0 ms) were 88% and 97% for RA non-PV, 81% and 73% for SEP non-PV, 65% and 95% for LA non-PV, respectively.

Conclusions

The analysis of intra-atrial activation sequences was useful to differentiate non-PV trigger areas. A simple algorithm to localize the area of non-PV trigger would be helpful to identify non-PV trigger sites in AF ablation.

Comparison of the Different Anesthesia Strategies for Atrial Fibrillation Catheter Ablation: A Systematic Review and Meta-Analysis

Background

Catheter ablation has become a widely applied intervention for treating symptomatic atrial fibrillation (AF), which can be performed under general anesthesia (GA), deep sedation, or conscious sedation (CS). But the strategy of anesthesia remains controversial.

Objectives

This systematic review and meta-analysis aims to compare the advantages of GA/deep sedation and CS in AF catheter ablation, including procedural parameters and clinical outcomes.

Methods

PubMed, Embase, and the Cochrane Library were searched up to November 2021 for randomized controlled trials and observational studies that assessed the outcomes of catheter ablation under GA/deep sedation or CS. Ten studies were included in this meta-analysis after screening with the inclusion and exclusion criteria. Heterogeneity between studies was evaluated by the I² index and the Cochran Q test, respectively; sensitivity analysis including meta-regression was performed if heterogeneity was high. Publication bias was assessed using a funnel plot and Egger' test.

Results

This meta-analysis found GA/deep sedation to be associated with a lower recurrence rate of AF catheter ablation (p=0.03). In terms of procedural parameters, there was no significant difference between the two groups for the procedural time (p=0.35) and the fluoroscopy time (p=0.60), while the ablation time was shorter in the GA/deep sedation group (p=0.008). The total complication rate and the incidence of serious adverse events were statistically insignificant between the two groups (p=0.07 and p=0.94). Meta-regression did not suggest any covariates as an influential factor for procedural parameters and clinical outcomes.

Conclusion

GA/deep sedation may reduce the risk of recurrence after AF ablation without increasing the incidence of complications. GA/deep sedation shortens the ablation duration, although there is no statistical difference in other procedural parameters between GA/deep sedation and CS.

Postablation Atrial Arrhythmias

Atrial arrhythmias, including atrial tachycardia and atrial flutter, are not uncommon after prior ablation. Mechanisms for arrhythmogenesis may vary and include recurrent conduction through sites of ablation, leading to recurrence of prior ablated arrhythmias and creation of new substrate. Incidence of postablation atrial arrhythmias varies across studies and may relate to the approach to ablation, including extent of ablation performed, or to extent of substrate identified at the time of prior ablation and how that relates to the lesion set. In addition, postablation atrial arrhythmias may be more common in certain types of cardiomyopathy, including hypertrophic cardiomyopathy.

Anaesthesia use in catheter ablation for atrial fibrillation: a systematic review and meta-analysis of observational studies

Objectives

This meta-analysis and systematic review seeks to compare both characteristic parameters and procedural outcomes of atrial fibrillation (AF) catheter ablation in patients under general anaesthesia (GA)/deep sedation and mild/moderate sedation.

Background

Catheter ablation has become a widely applied intervention for treating symptomatic AF and arrhythmias that are refractory to medical therapy. It can be conducted through from mild sedation to GA.

Methods

PubMed and Embase were searched up to July 2018 for randomised controlled trials, cohort and observational studies that assessed the outcomes of catheter ablation under GA/deep sedation or mild/moderate sedation. Nine studies were included in this meta-analysis after screening with the inclusion and exclusion criteria. Heterogeneity between studies and publication bias was evaluated by I² index and Egger's regression, respectively.

Results

Our meta-analysis found catheter AF ablation with GA/deep sedation to be associated with reduced risk of recurrence (RR: 0.79, 95% CI 0.56 to 1.13, p=0.20) and complications (RR: 0.95, 95% CI 0.64 to 1.42, p=0.82), though statistically insignificant. In terms of procedural parameters, there was no significant difference between the two groups for both procedural time (SMD: -0.13, 95% CI -0.90 to 0.63, p=0.74) and fluoroscopy time (SMD: -0.41, 95% CI -1.40 to 0.58, p=0.41). Univariate meta-regression did not reveal any covariates as a moderating factor for complication and recurrence risk.

Conclusion

Apart from an increased likelihood of procedural success, ablation by GA/deep sedation was found to be non-significantly different from the mild/moderate sedation approach in both procedural parameters and outcome measures.

Catheter Ablation of Paroxysmal Atrial Fibrillation Originating from Non-pulmonary Vein Areas

Pulmonary veins (PVs) are a major source of ectopic beats that initiate AF. PV isolation from the left atrium is an effective therapy for the majority of paroxysmal AF. However, investigators have reported that ectopy originating from non-PV areas can also initiate AF. Patients with recurrent AF after persistent PV isolation highlight the need to identify non-PV ectopy. Furthermore, adding non-PV ablation after multiple AF ablation procedures leads to lower AF recurrence and a higher AF cure rate. These findings suggest that non-PV ectopy is important in both the initiation and recurrence of AF. This article summarises current knowledge about the electrophysiological characteristics of non-PV AF, suitable mapping and ablation strategies, and the safety and efficacy of catheter ablation of AF initiated by ectopic foci originating from non-PV areas.