Usefulness of empiric superior vena cava isolation in paroxysmal atrial fibrillation ablation: a meta-analysis of randomized clinical trials.

BACKGROUND: The long-term success rate of pulmonary vein isolation (PVI) is suboptimal due to the presence of non-pulmonary vein (PV) foci that can trigger atrial fibrillation (AF) in up to 11%. Among non-PV triggers, the superior vena cava (SVC) is a major site of origin of ectopic beats initiating AF. OBJECTIVE: To compare data from randomized controlled trials (RCTs) assessing PVI + empiric SVC isolation (SVCI) versus PVI alone in terms of AF recurrence, procedure-related complications, and fluoroscopic and procedural times. METHODS: A search of online scientific libraries (from inception to April 1, 2024) was performed. Four RCTs were considered eligible for the meta-analysis totaling 600 patients of whom 287 receiving PVI + SVCI and 313 receiving PVI alone. RESULTS: In the overall population, SVCI + PVI was associated with a non-significant reduction of AF recurrence at follow-up (0.66 [0.43;1.00], p = 0.05, I2 0%). In patients with paroxysmal AF (PAF), a significant reduction of AF recurrence was related to SVCI + PVI (11.7%) as compared to PVI alone (19.9%) (0.54 [0.32;0.92], p = 0.02, I2 0%). No statistical differences were found among the groups in terms of fluoroscopic (3.31 [- 0.8;7.41], p = 0.11, I2 = 91%), procedural times (5.69 [- 9.78;21.16], p = 0.47, I2 = 81%), and complications (1.06 [0.33;3.44], p = 0.92, I2 = 0%). CONCLUSION: The addition of SVCI to PVI in patients in PAF is associated with a significant lower rate of AF recurrence at follow-up, without increasing complication rates and procedural and fluoroscopy times.

A validation study of the accuracy of the atrial pace map assessed with intracardiac pattern matching: Potential utility of non-pulmonary vein mapping.

BACKGROUND: Identification of infrequent nonpulmonary vein trigger premature atrial contractions (PACs) is challenging. We hypothesized that pace mapping (PM) assessed by correlation scores calculated by an intracardiac pattern matching (ICPM) module was useful for locating PAC origins, and conducted a validation study to assess the accuracy of ICPM-guided PM. METHODS: Analyzed were 30 patients with atrial fibrillation. After pulmonary vein isolation, atrial pacing was performed at one or two of four sites on the anterior and posterior aspects of the left atrium (LA, n = 10/10), LA septum (n = 10), and lateral RA (n = 10), which was arbitrarily determined as PAC. The intracardiac activation obtained from each pacing was set as an ICPM reference consisting of six CS unipolar electrograms (CS group) or six CS unipolar electrograms and four RA electrograms (CS-RA group). RESULTS: The PM was performed at 193 ± 107 sites for each reference pacing site. All reference pacing sites corresponded to sites where the maximal ICPM correlation score was obtained. Sites with a correlation score ≥98% were rarely obtained in the CS-RA than CS group (33% vs. 55%, P = .04), but those ≥95% were similarly obtained between the two groups (93% vs. 88%, P = .71), and those ≥90% were obtained in all. The surface areas with correlation scores ≥98% (0[0,10] vs. 10[0,35] mm2, P = .02), ≥95% (10[10,30] vs. 50[10,180] mm2, P = .002) and ≥90% (60[30,100] vs. 170[100,560] mm2, P = .0002) were smaller in the CS-RA than CS group. CONCLUSIONS: ICPM-guided PM was useful for identifying the reference pacing sites. Combined use of RA and CS electrograms may improve the mapping quality.

Impact of residual induction number of non-pulmonary vein foci on the 2-year outcomes in patients with paroxysmal atrial fibrillation.

BACKGROUND: Residual non-pulmonary vein (PV) foci are significantly associated with atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI). However, we previously reported among patients with non-PV foci induced only once, none experienced AF recurrence. Thus, we aimed to investigate the correlation between the residual induction number of non-PV foci and ablation outcome in paroxysmal AF patients. METHODS AND RESULTS: We investigated 55 paroxysmal AF patients with residual non-PV foci after PVI and ablation of non-PV-foci. Study patients were classified into the residual one-time induction of non-PV foci (residual OTI-nPVF) group (n = 23) and residual repeatedly induced non-PV foci (residual RI-nPVF) group (n = 32). Furthermore, the residual RI-nPVF group was divided into the low inducibility group (n = 10) and high inducibility group (n = 22) according to the presence or absence of non-PV foci provoked by two sets of drug induction tests (non-PV foci inducibility). In addition, the latter was divided into the ablation group (n = 14) or observation group (n = 8). The 2-year AF recurrence-free rate in the residual RI-nPVF group was significantly lower compared to the residual OTI-nPVF group (53% vs. 90%, p = 0.018). There was no significant difference of the 2-year AF recurrence-free rates in the inducibility of non-PV foci (p = 0.913) and the presence or absence of ablation (p = 0.812) in the residual RI-nPVF group. CONCLUSIONS: Among paroxysmal AF patients, the presence of residual RI-nPVF was associated with higher AF recurrence compared to residual OTI-nPVF. Furthermore, within residual RI-nPVF subgroup, non-PV foci inducibility or ablation of some residual RI-nPVF did not affect ablation outcome.

Tall P-waves in inferior leads: A case of coexisting ectopic rhythm and atrial fibrillation arising from the superior vena cava.

Suppression of atrial fibrillation (AF) arising within the superior vena cava (SVC) requires SVC electric isolation (SVCI) without sinus node (SN) injury. If an ectopic rhythm and AF trigger coexist within the SVC, the intra-SVC ectopic rhythm complicates the pre-SVCI search for the SN. This coexistence is without precedent; however, it is important to carefully locate the SN to prevent injury during SVCI. This case shows a paroxysmal AF with both phenomena coexisting in the SVC. Moreover, outpatient electrocardiographic assessment for tall P-waves in inferior leads before catheter ablation could predict these phenomena and enable safer SVCI.

Effect of isolation feasibility of non-pulmonary vein foci on efficacy of ablation for atrial fibrillation: comparison of the isolation and focal ablation methods.

PURPOSE: Atrial fibrillation (AF) mainly originates from the pulmonary vein (PV). However, some AF triggers originate from other sites, namely non-PV foci, which are related to recurrence after AF ablation. This study aimed to evaluate the effects of isolation feasibility (isolability) of non-PV foci on the efficacy of AF ablation. METHODS: Overall, 1855 patients with AF (age, 64.6 ± 10.9 years; 82% paroxysmal) underwent PV isolation, followed by induction and ablation of non-PV foci. Among them, 545 (29%) patients had non-PV foci; these patients were categorized into those with isolable non-PV foci (n = 196, 36%) and those with non-isolable non-PV foci (n = 349, 64%). RESULTS: During a mean follow-up of 31.2 ± 15.6 months, recurrence was higher in the non-isolable group than in the isolable group (34% vs. 19%, P < 0.01). Kaplan-Meier analyses revealed a significantly better 1-year clinical outcome in the isolable group than in the non-isolable group (88.0% vs. 78.4%, P < 0.001; hazard ratio (HR), 0.56; 95% confidence interval (CI), 0.39-0.81). This outcome was not inferior to that of patients without non-PV foci (88.3% vs. 90.8%, P = 0.81). The non-isolable group showed poorer clinical outcomes than patients without non-PV foci (78.4% vs. 90.8%, P < 0.001; HR, 1.37; 95% CI, 1.22-1.53). Cox regression analysis revealed that isolability (HR, 0.56; 95% CI, 0.36-0.89) and unmappability (HR, 2.89; 95% CI, 1.55-5.37) of non-PV foci were significant predictors of arrhythmia recurrence. CONCLUSION: The isolability of non-PV foci was a significant factor affecting the achievement of better clinical outcomes following AF ablation in patients with non-PV foci.

Catheter ablation of ganglionated plexi in patients with adenosine triphosphate-induced atrial fibrillation after pulmonary vein isolation.

Intravenous ATP may induce atrial fibrillation (AF). ATP shares similar receptor-effector coupling systems with acetylcholine. However, the association between an ATP injection and the hyperactivity of the intrinsic cardiac autonomic nervous system, known as ganglionated plexi (GPs), is not well understood. We describe a series of patients with non-pulmonary vein (PV) trigger sites provoked by an ATP injection, and assess the feasibility of a ganglionated plexus (GP) ablation. We retrospectively analyzed 547 patients (69% male; mean age 67.4 ± 10.4 years; 38.5% non-paroxysmal AF) who underwent a total of 604 ablation procedures. Intravenous ATP was administered with an isoproterenol infusion during sinus rhythm after a pulmonary vein isolation in 21.3%, Box isolation in 78.6%, and SVC isolation in 52.0% of the procedures, respectively. We reviewed the incidence, the distribution of the foci, and the ablation outcomes in patients with ATP-induced AF. A total of seven patients (1.3%) had ATP-induced AF. Foci were identified in the coronary sinus (CS) in six patients, right atrial posterior wall (RAPW) adjacent to the interatrial groove in two, mitral annulus in two, ligament of Marshall in one, right septum below the foramen ovale in one and left atrial posterior wall in one, respectively. Among these trigger foci, we confirmed the vagal response by high-frequency stimulation in the CS and RAPW in six and two patients, respectively. After a median RF time of 2.9 min (range 2.5-11.3) targeting these foci, in five of six patients who received a repeat ATP injection, the AF became non-inducible. ATP-provoked trigger foci were distributed among certain sites that overlapped with the distribution of the GPs. The GP ablation was effective for this rare, but challenging situation.

Effect of ganglionated plexi ablation by high-density mapping on long-term suppression of paroxysmal atrial fibrillation - The first clinical survey on ablation of the dorsal right plexusus.

BACKGROUND: Long-term outcomes of suppressing paroxysmal atrial fibrillation (PAF) with additive ganglionated plexus (GP) ablation (GPA) remains unknown. OBJECTIVES: The aim of the study is to assess potential role of additional GPA for PAF suppression. METHODS: This study consisted of 225 patients; 68 (group A: 58 male, aged 60 ± 11 years) underwent pulmonary vein isolation (PVI) alone and 157 (group B: 137 male, aged 61 ± 11 years) GPA followed by PVI. GPA was performed based on the high-density mapping with high-frequency stimulation (HFS) delivered to left atrial (LA) major GP. The latter 85 group B patients (54%) underwent ablation to a posteromedial area within superior vena cava as a part of dorsal right atrial GP (SVC-Ao GP). RESULTS: In group B, HFS was applied to 126 ± 32 sites, with a median of 47 GP sites (40.0%) being ablated. In patients undergoing an SVC-Ao GPA, HFS and the SVC-Ao GPA were applied at a median of 15 and 4 sites (29.4%), respectively. The PVI with a GPA provided higher PAF suppression than a PVI alone during more than 4 years of follow-up (56.7% vs 38.2%, odds ratio: 0.42, 95% confidence interval: 0.23-0.76, P < .05), but the SVC-Ao GPA did not provide further suppressive effects. Multivariate analyses revealed that tachycardia-bradycardia syndrome and non-PV foci were independent predictors of PAF recurrence after PVI with a GPA (P < .01). CONCLUSION: GPA to LA major GP by high-density mapping provides long-term benefits for PAF suppression over 4 years of follow-up, but the effect of an empiric SVC-Ao GPA could not be appreciated, suggesting little effect on suppressing non-PV foci.

Importance of the length of the myocardial sleeve in the superior vena cava in patients with atrial fibrillation.

BACKGROUND: Pulmonary vein (PV) antrum isolation (PVAI) has proven to be a useful strategy for radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) worldwide. However, non-PV foci, especially from the superior vena cava (SVC), play an important role in initiating and maintaining AF. METHODS: In all, 427 consecutive patients with non-valvular AF who were admitted to our hospitals to undergo RFCA of AF using an EnSite™ system were evaluated. The length from the top of the sinus node to the top of the myocardial sleeve of SVC (L-SVC), longer and shorter diameter of SVC of 1 cm above of junction of right atrium and SVC, and local activation time (LAT) of SVC were measured. Then, the SVC firing was evaluated by an intravenous administration of isoproterenol and adenosine triphosphate. RESULTS: L-SVC, longer and shorter diameter of SVC, and LAT of SVC were significantly longer in the SVC firing group than non-SVC firing group (P < .05). Moreover, in accordance with the L-SVC, the frequency of the SVC firing significantly increased (P < .001). A univariate analysis and multivariate statistical analysis revealed that L-SVC longer than 37.0 mm (odds ratio 6.39) and longer diameter of SVC (odds ratio 6.78) were independent risk factors for SVC firing in patients with AF who underwent RFCA of AF. CONCLUSIONS: In view of these findings, L-SVC longer than 37.0 mm longer diameter SVC longer than 17.0 mm may be one of the important predictors of SVC firing in patients with AF.

Impact of diagnosis-to-ablation time on non-pulmonary vein triggers and ablation outcomes in persistent atrial fibrillation.

INTRODUCTION: Non-pulmonary vein (PV) triggers are a major cause of atrial tachyarrhythmia (ATA) recurrence after catheter ablation. However, the effect of the diagnosis-to-ablation time (DAT) on non-PV triggers in persistent atrial fibrillation is unknown. METHODS AND RESULTS: This observational study evaluated 502 consecutive persistent AF patients who underwent initial ablation. We compared 408 patients whose DAT was <3 years with 94 patients whose DAT was ≥3 years. Following PV and posterior wall isolation, 193 non-PV triggers, including 50 AFs, 30 atrial tachycardias (ATs), and 113 repetitive atrial premature beats, were elicited and ablated in 137 (27%) patients. Specifically, 80 non-PV AF/AT triggers were provoked in 64 (13%) patients, being identified more frequently in the DAT ≥ 3 years group than in the DAT < 3 years group (20% vs. 11%, p = .025) especially with a higher prevalence of coronary sinus/inferior left atrial triggers. During a median follow-up of 770 days, the ATA recurrence-free rate was higher in the DAT < 3 years group than the DAT ≥ 3 years group (79% vs. 53% at 2 years, p < .001). In a multivariate analysis, female sex (odds ratio: 2.70, p = .002) and a longer DAT (odds ratio: 1.13/year, p = .008) were predictors of non-PV AF/AT triggers, and a longer DAT (hazard ratio: 1.12/year, p < .001) and non-PV AT/AF triggers (hazard ratio: 1.79, p = .009) were associated with ATA recurrence. CONCLUSION: Early ablation after the first diagnosis of persistent AF may reduce emerging non-PV AF/AT triggers and ATA recurrence.

Presence of non-pulmonary vein foci in patients with atrial fibrillation undergoing standard ablation of pulmonary vein isolation: Clinical characteristics and long-term ablation outcome.

BACKGROUND: The clinical characteristics of atrial fibrillation (AF) resulting from non-pulmonary vein (PV) triggers remain unknown. This study aimed to evaluate the clinical characteristics of patients with AF caused by non-PV triggers, localization of non-PV foci, clinical differences, and clinical outcomes after catheter ablation in each AF focus. METHODS: A total of 2967 patients who underwent initial catheter ablation for paroxysmal or persistent AF were examined. After PV isolation, all patients underwent high-dose isoproterenol infusion to assess the existence of non-PV foci. RESULTS: Non-PV foci were identified in 564 patients (19.2%). The localization of successfully ablated non-PV foci in 514 patients were the superior vena cava (SVC: 213 cases), interatrial septum (IAS: 125 cases), coronary sinus (CS: 98 cases), right atrium (RA: 125 cases), left atrium (LA: 114 cases), and unmappable (50 cases). Multivariate analysis revealed that female gender, low body mass index (BMI), non-paroxysmal AF (PAF), and sick sinus syndrome were independent and significant indicators of non-PV foci. In the multivariate analysis of each AF focus, female gender, low BMI, and non-PAF were significant predictors of IAS and CS foci, RA and IAS foci, and CS foci, respectively. In addition, dilatation of the LA was significantly associated with LA foci, whereas RA, LA, IAS, and CS foci were associated with AF recurrence. CONCLUSION: These findings could help to identify patients at a higher risk of AF caused by non-PV triggers and clarify the clinical difference according to the localization of non-PV foci.

The effect of posterior wall isolation for persistent atrial fibrillation on recurrent arrhythmia.

INTRODUCTION: It is important to consider recurrent arrhythmia after catheter ablation for persistent atrial fibrillation (AF) for planning an ablation strategy. However, the studies are limited to pulmonary vein isolation (PVI) plus posterior wall isolation (PWI), which were reported to improve procedural outcomes. The objective of this study is to evaluate the effect of PWI on recurrent arrhythmia. METHODS: This is an observational study on patients with persistent AF comparing PVI plus PWI and PVI only strategies. In PVI plus PWI group, linear ablation of the left atrium roofline and bottom line were performed to achieve PWI after PVI. Some patients with AF recurrence underwent the second procedure. The presence of recurrent arrhythmia and results of the second procedures were evaluated. RESULTS: A total of 181 patients (mean age, 66.9 ± 10.2 years; male, 76.8%) were included. PVI plus PWI group and PVI only group consisted of 90 and 91 patients, respectively. AF recurrence was observed in 28 of 90 (31.1%) patients with PVI plus PWI and in 43 of 91 (47.3%) with PVI only, and log-rank test did not show any significant difference (p = .35). The occurrence of recurrent persistent AF was significantly lower in PVI plus PWI group than in PVI only group (5/90; 5.6% vs. 18/91; 20.9%, p = .002). There was no significant difference between the two groups in recurrent paroxysmal AF and atrial tachycardia (AT). CONCLUSION: PWI, in addition to PVI, for persistent AF was significantly related to fewer episodes of recurrent persistent AF, and it did not increase recurrent AT.

Predictors of non-pulmonary vein foci in paroxysmal atrial fibrillation.

PURPOSE: Progress of balloon devices for pulmonary vein (PV) isolation in atrial fibrillation (AF) has been remarkable. However, these techniques were specialized in pulmonary vein treatment; predicting non-PV foci in advance is important to decide the treatment strategy. In this study, we investigate the predictors for paroxysmal AF. METHODS: Subjects were consecutive paroxysmal AF patients who underwent high-dose isoproterenol provocation after PV isolation in the first session. The PV group (n = 102) and non-PV group (n = 222) were defined as the patients with and without non-PV ablation, respectively. Non-PV ablation was performed when frequent repetitive premature atrial contractions or triggered AF occurred spontaneously or by isoproterenol provocation. Predictors of non-PV origin in paroxysmal AF patients were examined using clinical characteristics and preoperative echocardiography. RESULTS: In the multivariate logistic regression analysis, female sex, body mass index (BMI < 23.8), absence of hypertension, and higher ratio of mitral early diastolic peak (E-wave) to early diastolic mitral annulus peak (e') velocity (E/e' > 8.44) were significant independent predictors of non-PV foci (hazard ratio 2.04, 1.88, 3.63, and 2.33; 95% confidence interval 1.17-3.55, 1.05-3.39, 1.72-7.67, and 1.34-4.05; p = 0.011, 0.035, < 0.001, and 0.003, respectively). If a patient had these four factors, non-PV was detected with 96.8% specificity. CONCLUSION: Female sex, lower BMI, absence of hypertension, and higher E/e' were significant indicators of non-PV foci in patients with paroxysmal AF. Reviewing these factors in advance may be useful for selecting a device to perform pulmonary vein isolation.

Association between the locations of non-pulmonary vein triggers and ablation outcomes in repeat procedures after cryoballoon ablation of paroxysmal atrial fibrillation.

PURPOSE: We examined the characteristics of non-pulmonary vein (PV) triggers in repeat ablation after cryoballoon ablation for paroxysmal atrial fibrillation (PAF). METHODS: This study evaluated 119 patients undergoing a second ablation procedure for recurrent atrial tachyarrhythmia (ATA) after cryoballoon PV isolation (CB-PVI) for PAF. RESULTS: Fifty-three of 119 (45%) patients had PV reconnection. All reconnected PVs were isolated. No non-PV triggers were elicited in 42/119 (35%) patients (NNPV group). In 77/119 (65%) patients, 139 isoproterenol-induced non-PV triggers, including 45 triggers that initiated AF, were identified. Non-PV triggers initiating AF were observed at the superior vena cava (SVC), left atrial posterior wall (LAPW) including the PV antra, interatrial septum, right atrium, left atrial appendage/mitral anulus, and coronary sinus in 14 (12%), 10 (8%), 8 (7%), 7 (6%), 4 (3%), and 2 (2%) patients, respectively. Non-PV triggers originated from only the SVC and/or LAPW including the PV antra, and the SVC and/or LAPW was isolated in 18/119 (15%) patients (SVC/LAPW group). Non-PV triggers originating from other sites were focally ablated in 59/119 (50%) patients (OS group). During a median 461 days of follow-up, 39/42 (93%), 17/18 (94%), and 38/59 (64%) patients in the NNPV, SVC/LAPW, and OS groups, respectively, remained ATA recurrence-free. The recurrence rate was higher in the OS group than in the NNPV (P = 0.005) or SVC/LAPW groups (P = 0.042). CONCLUSIONS: Over half of patients had non-PV triggers at subsequent ablation after CB-PVI. Non-PV triggers from the SVC/LAPW can be eliminated more successfully than triggers from other sites.

A new method of superior vena cava isolation without phrenic nerve injury by longitudinal ablation parallel to the phrenic nerve: a case report.

BACKGROUND: Superior vena cava (SVC) isolation has improved the outcomes of paroxysmal atrial fibrillation (AF) originating from the SVC. However, right phrenic nerve (PN) injury is a major complication of this procedure. Therefore, in cases where the right atrium (RA)-SVC conduction site is near the PN, tremendous care is required to prevent PN injury. CASE SUMMARY: Repeated SVC isolation was performed due to the recurrence of SVC-triggered AF. The RA-SVC activation map revealed that the partial conduction block line was detected, and the propagation broke through the gap at the course of the PN site from the RA to the SVC. Since the course of the PN identified at high-output pacing was wide, the SVC was isolated by making longitudinal lines on both sides of the PN in a cranial direction, except for where low-output pacing captured, confirming compound muscle action potential to detect PN injury. Eventually, the SVC was successfully isolated without PN injury, and the sinus rhythm was maintained without antiarrhythmic drugs during a 14-month follow-up period. CONCLUSION: Superior vena cava isolation was difficult depending on the course of the PN, and some methods to avoid PN injury were reported. However, this method can facilitate safe and effective SVC isolation with the conventional system, including the cases with AF foci located on the course of the PN.