Ganglionated Plexi Ablation Research Articles

Left Atrial Size May Predict Blood Pressure Improvement After Ganglionated Plexi Ablation in Addition to Pulmonary Vein Isolation.

Hypertension (HTN) and atrial fibrillation (AF) commonly co-exist. An improvement in control of HTN in a subset of patients undergoing AF ablation was previously demonstrated by our group. In the present study, we aimed to assess whether left atrial (LA) size based on transthoracic echocardiography may predict the patients who demonstratebetter HTN improvement after ganglionated plexus ablation (GPA) in addition to pulmonary vein isolation (PVI). This was a retrospective chart review of patients with AF and HTN who underwent GPA+PVI. Patients were divided into 2 groupsbased on LA size: Patients with normal LA size and patients with LA enlargement. Systolic blood pressure (SBP) levelswere compared at baseline, and 3, 6, and 12 months post-ablation. The primary endpoints of the study weremean systolic blood pressure change compared between groups from baseline to 12-months, as well as the absolute difference in systolic blood pressure at 12 months follow-up.Medical therapy for HTN was also assessed before the procedure, and at 12 months post-procedure. 53 patients (37 with LA enlargement, 16 with normal LA size) met inclusion criteria. At 12 months follow-up, SBP was 136.46 ± 22.38 mmHg in patients with LA enlargementand 118.25 ± 9.81 mmHg in patients with normal LA size (estimated difference of 19.04 ± 6.98 mmHg, p = 0.01). Patients with normal LA size were on significantly fewer anti-hypertensive agents at 12 months (2.33 ± 1.49 vs. 1.44 ± 1.21, p < 0.05). In patients undergoing PVI+GP ablation, normal LA size may predict HTN improvement at 12 months post-procedure. Normal LA size may identify hypertensive AF patients for whom autonomic modulation could be an effective therapy.

The outcome of ablation for non-paroxysmal atrial fibrillation targeting spatiotemporal electrogram dispersion compared with ganglionated plexi ablation

Abstract Background Although catheter ablation targeting ganglionated plexi (GP) playing an important role in formation of triggers and substrates of atrial fibrillation (AF) has been reported as one of the effective ablation strategies in non-paroxysmal AF (non-PAF) patients, its effectiveness varies among the study groups. More recently, ablation targeting spatiotemporal electrogram dispersion (STED) areas, assumed to contain AF drivers in forms of rotational activation is proposed. However, the optimal ablation strategy for non-PAF is still controversial since the exact mechanisms of non-PAF are not well understood. Purpose To investigate the effectiveness of GP ablation for autonomic modification and STED ablation for modulation of AF drivers. Methods Consecutive 149 non-PAF patients who underwent STED ablation in our center were enrolled. We detected STED areas within the whole left and right atrium during AF using PentaRay®, and ablated them. If AF was terminated during STED ablation, we finished the procedure without burning the remaining STED areas. If not, electrical cardioversion was applied. The outcome was compared with that in consecutive 156 non-PAF patients undergoing GP ablation previously in our center. Results (1) The clinical characteristics were comparable between two groups (see Table). (2) A Kaplan-Meier curve showed that there was no significant difference between the freedom rates from non-PAF/non-paroxysmal atrial tachycardia (non-PAT) after single procedure in STED group and GP group (Figure, left). (3) However, the freedom rates from non-PAT in STED group was significantly lower than that GP group (Figure, right). Conclusions The recurrence type of atrial arrhythmia after ablation was remarkably different between ablation of STED and GP. STED ablation might eliminate fibrillatory conduction and control AF driver in patients with non-PAF. Freedom from atrial arrhythmia Funding Acknowledgement Type of funding source: None

Changes of QT interval in the acute phase after pulmonary vein isolation for paroxysmal atrial fibrillation

Abstract Introduction Pulmonary vein isolation (PVI) affects ganglionated plexi (GP) around the atrium, leading to a modification of the intrinsic cardiac autonomic system (ANS). In animal models, GP ablation has a potential risk of QT prolongation and ventricular arrhythmias. However, the impact of PVI on QT intervals in humans remains unclear. Purpose This study aims to evaluate the Impact of PVI on QT interval in patients with paroxysmal atrial fibrillation. Methods We analyzed consecutive 117 PAF patients for their first PVI procedures. 12-lead ECG was evaluated at baseline, 4 hr, day 1, 1 month, and 3 months after ablation. Only patients with sinus rhythm on 12-lead ECG at each evaluation point without antiarrhythmic drugs were included. Results Heart rate significantly increased at 4 hr, day 1, and 1 month. Raw QT interval prolonged at 4 hr (417.1±41.6 ms, P&amp;lt;0.001) but shortened at day 1 (376.4±34.1 ms, P&amp;lt;0.001), 1 month (382.2±31.5 ms, P&amp;lt;0.001), and 3 months (385.1±32.8 ms, P&amp;lt;0.001) compared to baseline (391.6±31.4 ms). Bazett- and Fridericia- corrected QTc intervals significantly prolonged at 4hr (Bazett: 430.8±27.9 ms, P&amp;lt;0.001; Fridericia: 425.8±27.4 ms, P&amp;lt;0.001), day1 (Bazett: 434.8±22.3 ms, P&amp;lt;0.001; Fridericia: 414.1±23.7 ms, P&amp;lt;0.001), 1M (Bazett: 434.8±22.3 ms, P&amp;lt;0.001; Fridericia: 408.2±21.0 ms, P&amp;lt;0.05), and 3M (Bazett: 420.1±21.8 ms, P&amp;lt;0.001; Fridericia: 407.8±21.1 ms, P&amp;lt;0.05) compared to baseline (Bazett: 404.9±25.2 ms; Fridericia: 400.0±22.6 ms). On the other hand, Framingham- and Hodges- corrected QTc interval significantly prolonged only at 4hr (Framingham: 424.1±26.6 ms, P&amp;lt;0.001; Hodges: 426.8±28.4 ms, P&amp;lt;0.001) and at day1 (Framingham: 412.3±29.3 ms, P&amp;lt;0.01; Hodges: 410.6±40.2 ms, P&amp;lt;0.05) compared to baseline (Framingham: 399.2±22.7 ms; Hodges: 400.7±22.8 ms). At 4 hr after ablation, raw QT and QTc of all formulas significantly prolonged than baseline. Raw QT and QTc prolongation at 4hr after ablation were more frequently observed in female patients. Multiple regression analysis revealed that female patient is a significant predictor of raw QT and QTc interval prolongation of all formulas 4hr after PVI. Conclusions Raw QT and QTc prolonged after PVI, especially in the acute phase. Female patient is a risk factor for QT prolongation in the acute phase after PVI. Funding Acknowledgement Type of funding source: None

Neurohumoral arrhythmogenic mechanisms and the treatment of atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia in humans. For AF to occur a trigger and substrate are necessary to start and perpetuate the arrhythmia. AF is induced by a complex interplay of clinical and biological risk factors. Despite of state-of-the-art therapeutic interventions AF remains a progressive, symptomatic disease. The first part of the thesis focusses on predicting patients who are at risk to develop AF. We found that body composition, especially a greater abdominal fat distribution, was association with new-onset AF. In the PREDICT-AF study we will investigate blood and atrial tissue markers of pathophysiological changes in new-onset AF in 150 patients, aiming to predict post-operative and new-onset AF and identify new targets of therapies. In the second part, we found that mineralocorticoid receptor antagonists significantly lowered the risk of new-onset or recurrent AF risk compared to control. This effect was more pronounced in patients with heart failure, but neutral in heart failure with a preserved ejection fraction. In the last part, we found that freedom of AF after thoracoscopic AF ablation plus ganglion plexus ablation was similar to control, but was associated with more major complications. Sinus node dysfunction (SND) occurred in 7.1% of patients after thoracoscopic AF ablation, but the majority of SND was of temporary nature and resolved within days postoperatively. In patients with an extremely enlarged left atrium the efficacy of standalone thoracoscopic AF ablation was considerable. The thromboembolic risk per risk factor of the CHA2DS2-VASc score was the highest in age group 65-74 years, while comorbid cardiovascular conditions were associated with lower, but still considerably increased risks. After a standardised evaluation visit with a dedicated AF nurse practitioner, a quarter of the patient remained under nurse-led care and almost half of patients could be referred back to a general practitioner.

Ganglionated Plexi Ablation for the Treatment of Atrial Fibrillation.

Atrial fibrillation (AF) is the most common type of cardiac arrhythmia and is associated with significant morbidity and mortality. The autonomic nervous system (ANS) plays an important role in the initiation and development of AF, causing alterations in atrial structure and electrophysiological defects. The intrinsic ANS of the heart consists of multiple ganglionated plexi (GP), commonly nestled in epicardial fat pads. These GPs contain both parasympathetic and sympathetic afferent and efferent neuronal circuits that control the electrophysiological properties of the myocardium. Pulmonary vein isolation and other cardiac catheter ablation targets including GP ablation can disrupt the fibers connecting GPs or directly damage the GPs, mediating the benefits of the ablation procedure. Ablation of GPs has been evaluated over the past decade as an adjunctive procedure for the treatment of patients suffering from AF. The success rate of GP ablation is strongly associated with specific ablation sites, surgical techniques, localization techniques, method of access and the incorporation of additional interventions. In this review, we present the current data on the clinical utility of GP ablation and its significance in AF elimination and the restoration of normal sinus rhythm in humans.

Catheter ablation of right atrial ganglionated plexi to treat cardioinhibitory neurocardiogenic syncope: a long-term follow-up prospective study

Several reports have focused on biatrial ganglionated plexi (GP) transcatheter ablation to treat cardioinhibitory neurocardiogenic syncope (CNS). Considering that anatomical studies showed a significant number of GP in the right atrium (RA), we hypothesized that RA "cardioneuroablation" could be an effective treatment for CNS. Eighteen consecutive patients (mean age: 36.9 ± 11.2years) with severe CNS were submitted to transcatheter ablation of GPs in the RA alone using an anatomical approach. Head up tilt test evaluation was performed during the follow-up period at 6, 12, and 24months and in case of significant symptoms, while heart rate variability parameters were evaluated at patients discharge at 1, 3, 6, 12, 24, and 36months after ablation. At a mean follow-up of 34.1 ± 6.1months, 3 (16.6%) patients experienced syncopal episodes and 5 patients (27.7%) only prodromal episodes. Syncopal and prodromal recurrences were significantly decreased both in overall population (P =0.001) and in symptomatic patients after ablation (P = 0.003). Heart rate variability analysis showed the loss of autonomic balance secondary to a reincrease of sympathetic tone after the acute phase faster than vagal tone more evident at 12months (LF/HF vs preablation, P < 0.001) and persistent until 24months. Finally, a good correlation was observed between symptomatic events and the extension of RF lesions in supero-, middle-, and infero-posterior RA areas (r = 0.73, P = 0.03; r = 0.85, P = 0.02; r = 0.87, P = 0.004, respectively). Cardioneuroablation in the RA can be considered safe and an effective technique to treat CNS episodes.

Long-term results of the maze procedure with GP ablation for permanent atrial fibrillation.

We investigated the effect of the maze procedure with intensive pulmonary vein isolation (PVI) guided by ganglionated plexus (GP) mapping (the Maze with GP ablation group) on a long-term postoperative maintenance of sinus rhythm in patients with permanent atrial fibrillation (AF) and compared with that in patients undergoing the maze procedure with the conventional PVI (the Maze group). We investigated 48 patients who underwent the maze procedure with GP ablation for persistent AF and 43 patients who underwent the maze procedure. The Maze procedure was conducted by the endocardial application of bipolar radiofrequency ablation and cryoablation. Conventional PVI was applied three times for the entrance of right and left PVs, respectively. Intensive PVI for GP ablation was repeated six-to-eight times for both sides of PVs to cover the bilateral GP regions identified by GP mapping. The duration of permanent AF, the prevalence of concomitant primary heart diseases, and the postoperative follow-up period were comparable between the two groups. At discharge, 1year, 5years after the surgery, sinus rhythm was maintained in 74.4%, 61%, and 40.5% of the Maze group. In contrast, it was maintained in 93.7%, 88.9%, and 75.7% of the Maze with GP ablation group. The cumulative freedom rate from AF at 10years after surgery was significantly higher in the Maze with GP ablation group. More intense PV isolation including adjacent GP may improve long-term results of maze procedure in patients with permanent AF.

Prolongation of QT interval after pulmonary vein isolation for paroxysmal atrial fibrillation.

Pulmonary vein isolation (PVI) affects the ganglionated plexi (GP) around the atrium leading to a modification of intrinsic cardiac autonomic system (ANS). In animal models, GP ablation has the potential risk of QT prolongation and ventricular arrhythmias. However, the impact of PVI on QT intervals in human remains unclear. We analyzed electrocardiograms of 117 consecutive patients with paroxysmal atrial fibrillation (AF) who underwent their first PVI procedures and maintained sinus rhythm without antiarrhythmic drugs at all evaluation points (4 h, 1 day, 1 month, and 3 months after PVI). Heart rate significantly increased at 4 h, 1 day, and 1 month. Raw QT interval prolonged at 4 h (417.1 ± 41.6 ms, p < .001) but shortened at 1 day (376.4 ± 34.1 ms, p < .001), 1 month (382.2 ± 31.5 ms, p < 0.001), and 3 months (385.1 ± 32.8 ms, p < 0.001) compared with baseline (391.6 ± 31.4 ms). Bazett-corrected QTc intervals were significantly prolonged at 4 h (430.8 ± 27.9 ms, p < .001), 1 day (434.8 ± 22.3 ms, p < .001), 1 month (434.8 ± 22.3 ms, p < .001), and 3 months (420.1 ± 21.8 ms, p < .001) compared with baseline (404.9 ± 25.2 ms). Framingham-corrected QTc intervals significantly prolonged at 4 h (424.1 ± 26.6 ms, p < .001) and 1 day (412.3 ± 29.3 ms, p < .01) compared with baseline (399.2 ± 22.7 ms). Multiple regression analysis revealed that female sex is a significant predictor of raw QT and QTc interval increase at 4 h after PVI. Raw QT and QTc were prolonged after PVI, especially in the acute phase. Female sex is a risk factor for QT increase.

Role of Ganglionated Plexus Ablation in Atrial Fibrillation on the Basis of Supporting Evidence.

The role of the autonomic nervous system (ANS) in the onset and maintenance of atrial fibrillation (AF) may be related to autonomic imbalance. The ANS may cause specific cellular electrophysiological phenomena, such as, shortening of the atrial effective refractory periods (ERPs) and ectopy based on firing activity in pulmonary vein myocytes. High frequency stimulation of atrial ganglionated plexi (GPs) may cause an increase in ERP dispersion and induce AF. Autonomic modification strategies by targeting GPs with catheter ablation have emerged as new targets. Various strategies have been used to detect location of GPs.However, it is still not clear which is the best method to localize GPs, how many GPs should be targeted, and what are the long-term consequences of these therapies. In this review, we discuss available evidence on the clinical impact of GP ablation to treat AF.

Clinical course of sinus node dysfunction after thoracoscopic surgery for atrial fibrillation\u2014analysis of the Atrial Fibrillation Ablation and Autonomic Modulation via Thoracoscopic Surgery (AFACT) study

PurposeSinus node dysfunction (SND) may complicate thoracoscopic surgical atrial fibrillation (AF) ablation. Identifying patients at risk is important, as SND may require temporary or permanent pacing. To determine the incidence of postoperative SND and duration of symptoms in patients who underwent thoracoscopic surgical ablation.MethodsPatients with paroxysmal or persistent AF included in the Atrial Fibrillation Ablation and Autonomic Modulation via Thoracoscopic Surgery (AFACT) study underwent pulmonary vein isolation and additional left atrial ablations on indication. Patients were randomized to ganglion plexus ablation or control. SND was defined as symptomatic or asymptomatic junctional rhythm exceeding sinus rate within 30 days postoperatively. The SND risk was assessed by using a univariable logistic regression model. The rate of pacemaker implantation was determined.ResultsThe AFACT study included 240 patients. SND developed in 17 (7.1%) patients, not affected by randomized treatment, p = 0.18. SND patients more often had persistent AF (88.2%) than patients without SND (57.4%), p = 0.01. After univariable testing, persistent AF (OR 5.57 CI 1.52–35.90, p = 0.02) and additional left atrial ablations (OR 12.10 CI 2.40–220.20, p = 0.02) were associated with postoperative SND. Six (35.3%) patients needed temporary pacing for 1–7 days; permanent pacemakers (PMs) were implanted for SND in five (29.4%) patients.ConclusionAdditional left atrial ablations strongly increase the SND risk. The majority of SND was temporary, and sinus rhythm resolved within days, which indicates that a conservative approach with regard to pacemaker implantation should be considered.

Vagal responses during cardioneuroablation on different ganglionated plexi: Is there any role of ablation strategy?

BackgroundCardioneuroablation has been used to treat vagally mediated bradyarrhythmias (VMB). The aim of this study is to assess vagal response (VR) characteristics during radiofrequency catheter ablation (RFCA) with different ganglionated plexus (GP) order. MethodsA total of 49 consecutive patients with VMB who underwent cardioneuroablation were enrolled. GPs were identified by electroanatomic-mapping-guided strategy. After all GP targets have been identified, patients were divided into 2 groups according to GP ablation strategy. In the left side first group, ablation order of GPs were left superior GP (LSGP), left inferior GP (LIGP), right superior GP (RSGP), and right inferior GP (RIGP). In the right side first group, ablation order was RSGP, RIGP, LSGP, and LIGP. ResultsIn the left side first group, LSGP was the most common GP site at which a VR was observed (36 of 40 cases, 90%). LIGP causes a VR in 9 of 40 (22.5%) cases. In the right side first group, VR was seen only 2 of 9 (22.2%) cases. Comparison of ablation strategy demonstrated a significant difference in VR during ablation on LSGP between groups. Despite, LSGP was the most common GP site at which a VR was observed both groups (90% in left side first group vs 11.1% in right side first group, p < 0.0001). In remaining GPs, VRs were not dependent on the ablation strategy and were not statistically different between groups. ConclusionThe present study demonstrates that the characteristics of VR during RFCA might change according to ablation order of GPs.

Different effects of additional ganglion plexus ablation on catheter and surgical ablation for atrial fibrillation: a systemic review and meta-analysis.

The effect of ganglion plexus (GP) ablation in addition to pulmonary veins isolation (PVI) for atrial fibrillation (AF) remained controversial between the catheter and surgical-based studies. Eleven studies (five randomized controlled trials and six nonrandomized studies) of 1750 patients were included in a meta-analysis to elucidate the incremental benefit of additional GP ablation in patients undergoing catheter or surgical ablation. Risk ratios were calculated for freedom from AF or AT recurrence after a single procedure. Additional GP ablation was associated with a better rhythm outcome for patients undergone catheter ablation but did not seem to increase freedom from AF/AT for surgical patients. Both paroxysmal and non-paroxysmal AF showed a positive outcome comparing additional GP ablation with PVI alone.

P2454Left atrial strain and recurrence of atrial fibrillation after thoracoscopic atrial fibrillation surgery

Abstract Background Left atrial (LA) strain has a prognostic value for atrial fibrillation (AF) recurrence after AF ablation. The value of LA strain as a predictor of AF recurrence after thoracoscopic AF surgery in patients in sinus rhythm (SR) or AF during echocardiography is unknown. Purpose To assess the association between LA strain and AF recurrence after thoracoscopic surgery for AF in both patients in SR and AF during baseline echocardiography. Methods Patients participating in the AFACT trial (n=240) with baseline transthoracic echocardiography (TTE) suitable for LA strain analysis were included in this subanalyses. All patients underwent thoracoscopic pulmonary vein isolation (PVI) with left atrial appendage (LAA) exclusion, and were randomized to ganglion plexus (GP) or no GP ablation. LA strain and mechanical dispersion (MD) of the LA reservoir, conduit and contraction phase were determined retrospectively from TTE images of both patients in AF and SR before thoracoscopic AF surgery. AF recurrence was defined as any recorded atrial tachyarrhythmia lasting &gt;30 sec during a one year FU period. Results A total of 204 patients (58.6±7.8 years, 73% male, 57% persistent AF) were included. Of the 204 patients 121 (59%) were in SR and 83 (41%) were in AF during baseline TTE. Patients in SR during TTE had higher LA strain values and lower MD compared to patients in AF. Of all patients, those with AF recurrence had lower LA strain of the reservoir phase (13.0% vs. 16.6%; p=0.003) and contraction phase (7.4% vs. 11.5%; p=0.012). MD of the contraction phase was increased in patients with AF recurrence (65.1msec vs. 19.2 msec; p=0.003). Multivariable cox regression analysis showed an association between LA strain, MD and AF recurrence (figure). Conclusions Left atrial strain and mechanical dispersion prior to thoracoscopic AF surgery are associated with recurrence of AF. LA strain showed to be a valuable tool to add in the decision making for thoracoscopic AF surgery regardless rhythm during baseline echocardiography.

P3752Ablation of the superior left ganglionic plexus is not necessary for effective denervation of the sinoatrial and atrioventricular nodes

Abstract Background Cardioneuroablation by targeting of atrial ganglionic plexi (GP) has been proposed as a new therapeutic option in selected patients with reflex syncope. Contribution of individual GPs to cardiac autonomic regulations is not fully established. Purpose Because consistent vagal responses have been observed during left superior pulmonary vein isolation in patients undergoing ablation for atrial fibrillation, we investigated whether standalone ablation of the superior left GP modifies the vagal input into the sinoatrial (SAN) and atrioventricular node (AVN). Methods Study hypothesis was investigated in otherwise healthy patients undergoing cardioneuroablation for symptomatic bradyarrhythmias. All had preprocedural atropine test suggesting functional disorder. Anatomically-navigated (CARTO-3) radiofrequency (RF) ablation (25–30 W/30 s/20 ml/min) at empirical GP sites was performed in general anaesthesia. Extracardiac high-frequency vagal nerve stimulation (25–60 V/30–50 Hz/0.05–0.1 ms) via right jugular vein was performed at baseline, after initial superior left GP ablation, and after the ablation of remaining septal and inferior GPs. High-frequency vagal nerve stimulation was always done in both sinus rhythm and atrial pacing. The elimination of all stimulation-induced vagal responses was the endpoint of the procedure. Results A study included 8 patients (34±8 years; 5 males). Six of them had recurrent syncope with cardioinhibitory response at the SAN (n=4), AVN (n=1) or both nodes (n=1); and 2 patients had symptomatic sinus bradycardia. At baseline, high-frequency vagal nerve stimulation induced long episodes of sinus arrest and advanced AV block in all patients. Cluster ablation at the superior left GP (RF time: 192±28 s) did not change the sinus rate (59±14 vs 60±15, NS), PQ interval (174±37 vs 173±37, NS), and did not induce any tangible change in SAN/AVN response to high-frequency vagal nerve stimulation. Subsequently, anterior right GP was targeted from the aspect of right atrium (n=7), from the anterior antrum of right pulmonary veins (n=6), and inferior GPs were targeted from the aspect of left atrium (n=7). This lesion set finally resulted in complete non-responsiveness of SAN and AVN to high-frequency vagal nerve stimulation in all patients. Ablation procedure overall (duration: 172±15 min; RF time: 988±306 s; radiation dose: 70±34 μGy·m2) led to sinus rate acceleration by a median of 29 (IQR: 18–38) bpm, increase of Wenckebach point by 21 (IQR: 9–28) bpm, and shortening of AVN effective refractory period by 40 (IQR: 15–73) ms. Conclusions Cardioneuroablation guided by extracardiac high-frequency vagal nerve stimulation can achieve complete denervation of SAN and AVN by ablation of postero(para)septal and inferior GPs only. Ablation of the superior left GP appears unnecessary and can be eliminated from the lesion set design.

Right anterior ganglionated plexus: The primary target of cardioneuroablation?

Catheter ablation of ganglionated plexus (GP) as cardioneuroablation in the left atrium (LA) has been used to treat vasovagal syncope (VVS). The purpose of this study was to assess the effects of ablation of GPs on heart rate and to observe the acute, short-term, and long-term effects after cardioneuroablation. A total of 115 consecutive patients with VVS who underwent cardioneuroablation were enrolled. GPs of the LA were identified by high-frequency stimulation and/or anatomic landmarks being targeted by radiofrequency catheter ablation. During ablation of right anterior ganglionated plexus (RAGP), heart rate increased from 61.3 ± 12.2 bpm to 82.4 ± 14.7 bpm (P <.001), whereas during ablation of other GPs only vagal responses were observed. During follow-up of 21.4 ± 13.1 months (median 18 months), 106 participants (92.2%) had no recurrence of syncope or presyncope. Holter data showed that minimal heart rate significantly increased at all follow-up time points (all P<.05), and mean heart rate remained higher than baseline 12 months after ablation (P = .001). Cardioneuroablation via GP ablation in the LA effectively inhibited the recurrence of VVS. Ablation of RAGP could increase heart rate immediately and for the long term. This unique phenomenon may provide a new potential approach for treatment of neural reflex syncope or bradyarrhythmias.

Optimum lesion set and predictors of outcome in persistent atrial fibrillation ablation: a meta-regression analysis.

Ablation of persistent atrial fibrillation (PsAF) has been performed by many techniques with varying success rates. This may be due to ablation techniques, patient demographics, comorbidities, and trial design. We conducted a meta-regression of studies of PsAF ablation to elucidate the factors affecting atrial fibrillation (AF) recurrence. Databases were searched for prospective studies of PsAF ablation. A meta-regression was performed. Fifty-eight studies (6767 patients) were included. Complex fractionated atrial electrogram (CFAE) ablation reduced freedom from AF by 8.9% [95% confidence interval (CI) -15 to -2.3, P = 0.009). Left atrial appendage [LAA isolation (three study arms)] increased freedom from AF by 39.5% (95% CI 9.1-78.4, P = 0.008). Posterior wall isolation (PWI) (eight study arms) increased freedom from AF by 19.4% (95% CI 3.3-38.1, P = 0.017). Linear ablation or ganglionated plexi ablation resulted in no significant effect on freedom from AF. More extensive ablation increased intraprocedural AF termination; however, intraprocedural AF termination was not associated with improved outcomes. Increased left atrial diameter was associated with a reduction in freedom from AF by 4% (95% CI -6.8% to -1.1%, P = 0.007) for every 1 mm increase in diameter. Linear ablation, PWI, and CFAE ablation improves intraprocedural AF termination, but such termination does not predict better long-term outcomes. Study arms including PWI or LAA isolation in the lesion set were associated with improved outcomes in terms of freedom from AF; however, further randomized trials are required before these can be routinely recommended. Left atrial size is the most important marker of AF chronicity influencing outcomes.

The cardiac autonomic nervous system: A target for modulation of atrial fibrillation.

The cardiac autonomic nerve system (CANS) is a potentially potent modulator of the initiation and perpetuation of atrial fibrillation (AF). In this review, we focus on the relationship between the autonomic nervous system (ANS) and the pathophysiology of AF and the potential benefit and limitations of neuromodulation in the management of this arrhythmia from eight aspects. We conclude that Activation and Remodeling of CANS involved in the initiation and maintenance of AF. The network control mechanism, innervation regions, and sympathetic/parasympathetic balance play an important role in AF substrate. And the formation of Complex Fractional Atrial Electrograms also related to CANS activity. In addition, modulating CANS function by potential therapeutic applications include ganglionated plexus ablation, renal sympathetic denervation, and low‐level vagal nerve stimulation, may enable AF to be controlled. Although the role of the ANS has long been recognized, a better understanding of the complex interrelationships of the various components of the CANS will lead to improvement of treatments for this common arrhythmia.

Epicardial ganglionated plexi ablation increases the inducibility of ventricular tachyarrhythmias in a canine postmyocardial infarction model.

Previous studies have shown that epicardial ganglionated plexi ablation (EGPA) could increase the risk of ventricular arrhythmias induced by acute myocardial ischemia. However, the long-term effect of EGPA in a canine postmyocardial infarction (MI) model is not well established. Twenty mongrel dogs were randomly divided into two groups: an MI group (n = 10) and an EGPA group (EGPA plus MI, n = 10). EGPA was achieved by ablation of four major ganglion plexi and the ligament of Marshall. The electrocardiograph (ECG) parameters, ventricular effective refractory period (ERP), inducibility of tachyarrhythmias, and ventricular fibrillation threshold (VFT) were measured at baseline and after 8 weeks. Tyrosine hydroxylase (TH) and nerve growth factor (NGF) expression levels in the peri-infarcted zone were also determined by immunohistochemistry in both groups at the end of the study. No significant differences were found in electrophysiological parameters at the baseline between the two groups. At the end of the 8-week follow-up, however, the EGPA group was associated with a longer QT interval, corrected QT (QTc) interval and ventricular ERP, larger dispersion of QT, QTc, and ERP, and higher inducibility of tachyarrhythmia and VFT when compared to the MI group. In addition, the density of TH and NGF in the peri-infarcted zone was also significantly increased in the EGPA group in comparison to the MI group. After the 8-week follow-up, EGPA increased the ventricular arrhythmia inducibility in the canine post-MI model, likely by increasing ventricular electrophysiological instability and promoting ventricular sympathetic remodeling.

Changes in heart rate variability in patients with atrial fibrillation after pulmonary vein isolation and ganglionated plexus ablation.

Pulmonary vein isolation (PVI) is the cornerstone in the treatment of patients with paroxysmal atrial fibrillation (PAF). Some research has suggested studies have shown that modification of ganglionated plexuses (GP), performed with PVI, could lead to even better outcomes. The aim of this study was to determine the effect of PVI on the autonomic system. Heart rate variability (HRV) was used as a marker of autonomic system activity. Twenty-six PAF patients underwent PVI (PVI group) and twenty patients underwent PVI plus a GP ablation (GP group). In each group, 5 min long ECG signals obtained before and after the electrophysiology EP study were analyzed. Time and frequency domain parameters were evaluated. Vagal responses during ablation were observed in 15 (58 %) patients in the PVI group and in 12 (60 %) patients in the GP group. The change in normalized power in the low frequency (LF) and in the LF/HF ratio, before and after ablation, was statistically significant in both groups (LF/HF 2.6+/-1.6 before vs. 1.4+/-1.7 after ablation in PVI group and LF/HF 3.3+/-2.6 before vs. 1.8+/-1.9 after ablation in the GP group). Relative to heart rate variability parameters, there were no differences between PVI and PVI + plus GP ablation.

Additional Ganglion Plexus Ablation During Thoracoscopic Surgical Ablation of Advanced Atrial Fibrillation: Intermediate Follow-Up of the AFACT Study.

The authors report the 2-year follow-up results of the AFACT (Atrial Fibrillation Ablation and Autonomic Modulation via Thoracoscopic Surgery) study. The AFACT study randomized patients with advanced atrial fibrillation (AF) to thoracoscopic AF ablation with or without additional ganglion plexus (GP) ablation. At 1 year, there was no difference in AF freedom between the groups, but autonomic modification may exert beneficial effects during longer follow-up. Patients underwent thoracoscopic pulmonary vein isolation, with additional left atrial lines in persistent AF patients, and were randomized 1:1 to ablation of the 4 major GP and Marshall ligament or no GP ablation (control). Patients were followed every 3 months up to 18 months and at 24 months. After an initial 3-month blanking period, all antiarrhythmic drugs were discontinued. The authors randomized 240 patients (age 59 ± 8 years, 73% men, 68% enlarged left atrium, 60% persistent AF), of whom 228 patients (95%) completed follow-up. Freedom of any atrial tachyarrhythmia did not differ significantly between the GP group (55.6%) and control group (56.1%) (p= 0.91), with no difference in paroxysmal (p= 0.60) or persistent AF patients (p= 0.88). Documented AF recurrences were similar between treatment arms: 11.8% (GP) versus 11.0% (control) had >3 recurrences/year (p= 0.82). More persistent AF patients (17.0%) than paroxysmal (3.2%) had >3 recurrences per year (p< 0.01). Despite this, 78% of patients were off antiarrhythmic drugs after 2 years. No procedural-related complications occurred in the second year. Additional GP ablation during thoracoscopic surgery for advanced AF does not affect freedom of AF recurrence. As GP ablation is associated with more major procedural complications, it should not routinely be performed. (Atrial Fibrillation Ablation and Autonomic Modulation via Thorascopic Surgery [AFACT]; NCT01091389).