Left Atrium Research Articles

Ten-year follow-up results of patients with persistent atrial fibrillation treated by combined pulmonary vein isolation and complex fractionated atrial electrocardiogram ablation

Abstract Background For persistent atrial fibrillation (AF), pulmonary vein isolation (PVI) alone is associated with lower success rate compared to paroxysmal AF and additional strategies are needed. Ablation targeting on complex fractionated atrial electrograms (CFAE) is an alternative method. Although clinical benefits of the strategy combined PVI and CFAE ablation have not been shown by large trials, clinical situations and consequences of this approach have not been clearly demonstrated during very long term follow-up. Purpose This study aimed to retrospectively investigate clinical outcomes of patients with persistent AF treated by the approach combined PVI and CFAE ablation during a follow-up period of 10 years. Methods 73 patients (59.4±8.1 years, 64 male, AF history 5.5 years) with persistent (23, 31.5%) and long-standing persistent AF (50, 68.5%) who underwent combined PVI and CFAE ablation in the first procedure were included. Structural heart disease was found in 9 patients, and a history of ablation for typical atrial flutter (AFL) in 4. A complete CFAE mapping in the left atrium and coronary sinus was performed with a 3-D mapping system (EnSite NavX). All CFAEs defined as electrograms with continuous activities or mean cycle length detected by the system <80 ms were eliminated. All patients were controlled regularly during the first year with 12-lead ECG and Holter monitoring and followed by annual control. The electronic health records for all patients were extensively investigated and the patients were interviewed in 2020-2022. Any documented atrial tachyarrhythmia (ATA) after 3-month blanking period was regarded as recurrence. Results Mean 2.2±1.2 (1-5) ablation procedures were performed in each patient. After index ablation, 18 (24.7%) were free of ATAs during 10-year follow-up. 26 (35.6%) had recurrence of only AF, 6 (8.2%) of only AFL and 23 (31.5%) had both AF and AFL. The proportion of AFL was 39.7% with 6 typical AFL. After multiple ablation procedures, 33 (45.2%) patients were free of ATA during the follow-up. 23 (31.5%) had recurrence of only AF, 5 (6.8%) of only AFL and 12 (16.4%) of both AF and AFL. The proportion of AFL was 23.2% with no typical AFL. At 1-year follow-up, freedom of ATAs in persistent AF was higher than that in long-standing AF (65.2 vs. 40.0%, p=0.033) and no significant difference was found after 2 years (47.8 vs. 34.0%, p=0.129) until 10 years (30.4 vs. 22.0%, p=0.167, Figure 1). No difference was observed between these subgroups after multiple procedures at 10-year follow-up (47.8 vs. 44.0%, p=0.708, Figure 2). Conclusions PVI plus CAFE ablation in patients with persistent AF led to a high recurrence of ATA after index ablation. Difference of ATA-freedom between persistent and long-standing persistent AF groups was found only 1 year after the index procedure, but not during further follow-up. Incidence of post-ablation AFL was particularly high, even after multiple ablation procedures.Figure 1Figure 2

Left atrial low-voltage area is associated with poor rhythm outcome and poor efficacy of left atrial additional ablation in patients with long-standing persistent atrial fibrillation ablation

Abstract Background Although left atrial additional ablation other than pulmonary vein (PV) isolation is often performed in order to modify arrhythmogenic substrate, rhythm outcome in patients with long-standing persistent atrial fibrillation (LS-PerAF) is still challenging. Left atrial low-voltage areas (LVAs) is correlated with degeneration of atrial myocardium, and atrial fibrillation (AF) recurrence following catheter ablation. However, in patients with LS-PerAF, the association between the prevalence of LVAs and rhythm outcome has not been clarified. We hypothesized that AF recurrence after AF ablation more frequently occurred in patients with LVAs than in those without, and that the prevalence of LVAs was associated with the efficacy of left atrial additional ablation. Purpose The purpose of this study was to investigate the association between the prevalence of LVAs and rhythm outcome or efficacy of left atrial additional ablation in patients with LS-PerAF ablation. Methods In total, 123 (age, 66 ± 9 years; female, 28 [23%]) consecutive patients who underwent initial ablation for LS-PerAF were included. Left atrial additional ablation was defined as an ablation for left atrium other than PV isolation and ablation for non-PV foci. The definition of LVAs was sites with a bipolar voltage of <0.5 mV covering ≥5 cm² of left atrium. Rhythm outcome after the catheter ablation was followed for 24 months. Results LVAs was found in 31 (25%) patients, and left atrial additional ablation was performed for 31 (25%) patients. Freedom from AF recurrence was significantly lower in patients with LVAs than in those without (Figure 1A). In contrast, freedom from AF recurrence was similar between patients with left atrial additional ablation and those without (Figure 1B). In patients without LVAs, freedom from AF recurrence was significantly higher in patients with left atrial additional ablation than in those without (Figure 2A). On the contrary, in patients with LVAs, freedom from AF recurrence during was similar between patients with left atrial additional ablation and those without (Figure 2B). Conclusions In patients undergoing LS-PerAF ablation, AF recurrence more frequently occurred in patients with LVAs than in those without. Only in patients without LVAs, freedom from AF recurrence was significantly higher in patients with left atrial additional ablation than in those without.Figure 1Figure 2

Two-year safety and effectiveness of hybrid ablation versus catheter ablation in patients with non-paroxysmal AF: mid-term results of the CEASE-AF trial

Abstract Background Hybrid Ablation for atrial fibrillation (AF) combines epicardial and endocardial ablation through a Heart Team approach to target durable, transmural isolation of the pulmonary veins (PV) and left atrial posterior wall (LAPW). While the primary efficacy endpoint at 12 months was met with a significant benefit increase for hybrid ablation, we now report the midterm durability of those results. Purpose To evaluate 24-months safety and effectiveness of Hybrid Ablation with left atrial appendage exclusion (LAAE) versus Catheter Ablation in patients with persistent AF/enlarged left atrium and longstanding persistent AF (LSPAF). Methods CEASE-AF is a prospective, multi-center, 2:1 randomized controlled trial. Eligible patients were 18-75 years of age, had symptomatic, drug-refractory persistent AF and enlarged left atrium (>4 cm) or LSPAF, and were undergoing a first ablation. Hybrid Ablation consisted of two stages: thoracoscopic epicardial radiofrequency (RF) ablation for PV and LAPW isolation and epicardial LAAE followed by endocardial ablation 91-180 days later. Catheter Ablation consisted of minimum PV isolation by endocardial RF ablation, and repeat ablation was allowed between 91-180 days. In both arms, additional lesions were permitted according to institutional practices. Effectiveness was freedom from AF/atrial flutter (AFL)/atrial tachycardia (AT) off anti-arrhythmic drugs (AAD) (except AADs not exceeding doses which previously failed) and was assessed through 48-h Holter monitoring reviewed by an independent core laboratory blinded to the study. Safety was major adverse events throughout the study, adjudicated by an independent Clinical Events Committee. Results There were 102 Hybrid Ablation and 52 Catheter Ablation patients; 26% were female, mean age was 60.7±7.9 years, mean LAD was 4.7±0.4 cm, and 19% had LSPAF with no differences between arms. The 12- and 24-month results are shown for comparison (Table). Through 24-months, effectiveness was 66.3% (63/95) in the Hybrid Arm and 33.3% (17/51) in the Catheter Arm (absolute difference 33.0% [95% CI 14.3%, 48.3%; p<0.001]). Major adverse event rates through 24-months were statistically similar at 10.8% (11/102) in the Hybrid Arm and 9.6% (5/52) in the Catheter Arm (p=1.0). Through 24-months, repeat ablations were performed in 7.4% (7/95) of the Hybrid Arm versus 37.3% (19/51) of the Catheter Arm (p<0.001), and cardioversions were performed in 14.7% (14/95) of the Hybrid Arm versus 29.4% (15/51) of the Catheter Arm (p=0.034) Conclusions: CEASE-AF demonstrated that superior effectiveness of Hybrid Ablation including LAAE versus Catheter Ablation was durable through 24-month follow-up, with 33% absolute improvement in freedom from AF/AFL/AT. Safety rates continued to be similar between arms. Three-year follow-up is ongoing.

Sinus nodal denervation by targeting the superior paraseptal ganglionated plexus: randomized comparison of right-atrial and bi-atrial cardioneuroablation guided by ablation index

Abstract Background Radiofrequency (RF) catheter ablation of superior paraseptal ganglionic plexus (SPSGP) that significantly suppresses the vagal modulation of the sinus node is used for the treatment of functional bradyarrhythmias. A reasonable effect can be achieved by targeting this plexus from the endocardial aspect of both the right and left atria. Purpose The study aimed to compare the acute efficacy of unifocal right-atrial (RA) and comparably extensive bi-atrial (BA) ablation of SPSGP for sinus nodal denervation as assessed by intraprocedural extracardiac vagus nerve stimulation (ECVS). Methods A population of 22 patients (age: 43±9 years, 55% males) undergoing cardioneuroablation (CAN) for functional bradyarrhythmias were randomized 1:1 to two ablation strategies that included: [1] single RF lesion at the very posterior site of the junction between right atrium and superior vena cava with ablation index (AI) = 800 (RA group) and [2] the same but twice smaller RF lesion (AI = 400) complemented with strictly contralateral left-atrial lesion (AI = 400) at the anterior vestibulum of right superior pulmonary vein (BA group). The effect of ablation was investigated by the post-ablation change in sinus rate and the attenuation of the response of the sinus node to ECVS (frequency: 50 Hz, pulse width: 0.05 ms, output: 1 V/kg [<70V], duration: 5 s) via the right internal jugular vein. Results Per-protocol ablation resulted in sinus acceleration by 9±15 bpm vs. 15±16 bpm (P=0.40) in RA vs. BA groups, respectively. Inducible sinus arrests were shortened by 4.7±4.2 s vs. 6.2±1.5 s (P=0.27) and reached the post-ablation level of 3.0±3.7 s vs. 1.0±0.3 s (P=0.08) in RA vs. BA groups, respectively. The results are also displayed in the Figure as medians, interquartile range (boxes) and total range (whiskers). Complete sinus nodal denervation was achieved in 8/11=73% vs. 11/11=100% patients (Fisher exact test P=0.21) in RA vs. BA groups, respectively. Practically 100% denervation efficacy in the BA group contrasted with 3 patients in the RA group in whom ablation had virtually no effect on ECVS-based indices (duration of post-ablation sinus arrests: 11.2, 8.7, and 5.2 s). Acute effects did not change substantially during the waiting period of 20±5 min. Conclusions In this small study with acute procedural endpoints, unifocal RA ablation of SPSGP appeared numerically less effective for sinus nodal denervation than comparably extensive BA ablation although the difference was formally non-significant. The ECVS-based outcome measure was valuable in detecting the differences between study groups. Change in sinus rate was not a reliable marker of sinus nodal denervation.

Pulsed field ablation for complex resistant atrial tachycardia recurring after radiofrequency ablation of persistent atrial fibrillation

Abstract Background There is a limited knowledge on immediate and long-term efficacy of pulsed field ablation (PFA) for residual atrial tachycardia (AT) recurring after persistent atrial fibrillation ablation (AF). Purpose To present immediate and medium-term outcome of PFA (Farapulse) for complex AT recurring after ≥1 radiofrequency ablation (RFA) of primary (longstanding) persistent AF. Methods In 5/2022-10/2023, 81 patients (64±8 years, 19 females) underwent PFA for complex AT in 83 PFA procedures after prior RFA procedure(s); in first (n=21), second (n=33), third (n=23), fourth (n=5), or fifth (n=1) repeat ablation procedure, respectively. Mapping/ablation strategy was directed by the CS activation/entrainment to: 1) no 3D mapping and direct PFA in left atrium (n=67); 2) PFA directly after 3D LA mapping (n=9); 3) PFA following RFA after 3D LA mapping (n=7). AT sources were classified as macroreentry (MRAT) (perimitral, roof-dependent, typical flutter) or localized (LOCAT) in case of smaller reentry or ectopic origin. Results At the procedure onset, persistent AT was present in 58 patients, in the remaining cases AT (n=21) or AF (n=4) were induced. AF eventually occurred at some time of procedure in another 10 patients and was terminated by ablation at LA ridge/CS/LOM region 8x, LA posterior wall 3x, LUPV 1x, RUPV 1x, and RA low lateral wall 1x. Only MRAT, only LOCAT, or both AT types were found at 34 (41%), 35 (42%), and 14 (17%) procedures, respectively. A total of 125 ATs was identified (1, 2, and 3 ATs in 52, 20, and 11 patients). MRAT (n=60) included 32 perimitral ATs, 20 roof-dependent ATs, and 8 typical flutters. LOCAT (n=65) included RUPV source (n=1), LA extraPV sources (n=59), and RA sources (n=5). SR was restored with a 5±7 PFA applications at the site of AF source, total of PFA deliveries was 71±27, and procedure and fluoroscopy times were and 89±37 and 9±5 minutes, respectively. In the 7 patients with initial ineffective 6, 6, 11, 5, 18, 10, and 2 minutes of RFA, the AT was converted into SR by subsequent 1, 4, 1, 13, 4, 24, and 20 PFA applications. All ATs were terminated and noninducibility was achieved in 82 (99%) and 74 (89%) procedures, respectively. In 52 patients with >3 month follow-up, 46 (88%) patients remain in stable SR (41 / 79%) off AAD); 3 and 3 patients have paroxysmal or persistent AT. Conclusion PFA with catheter Farapulse can affect complex/epicardial AT sources resistant to RFA in prior or present ablation procedure; however, there is a certain discrepancy between high efficacy in AT terminating and medium-term clinical outcome.

Revealing intracavitary catheter positions: artificial intelligence-enhanced localization with an electrogram-driven variational autoencoder model

Abstract Background The acquisition of electroanatomical (EA) maps in clinical electrophysiology procedures typically depends on locating intracardiac mapping catheters through magnetic triangulation with external patches placed on the patient's skin. However, this configuration is hampered by shifts in the reference system if the patient moves or if the setup changes during the procedure. Leveraging the feature extraction capabilities of artificial intelligence models, it becomes possible to assess catheter positions within the atria solely based on the information encoded in intracavitary electrograms (EGMs). Consequently, a neural network model could serve as an alternative or complementary system for locating EA mapping catheters, eliminating the need for external reference patches. Purpose We aimed to create a deep learning model utilizing a disentangled variational autoencoder (d-VAE) and unipolar EGM signals. The goal was to extract the precise position of a multi-electrode catheter within the left atrium and predict the specific atrial region in which it is situated, relying solely on the information derived from unipolar EGMs. Methods The model was trained using data from 51 patients with persistent atrial fibrillation who underwent pulmonary vein ablation. We exported 3D EA maps obtained with a 20-pole multi-electrode catheter, comprising a total of 40,000 unipolar EGMs with a duration of 30 seconds. Atrial geometries were segmented into 12 different areas (refer to the Figure). Subsequently, the d-VAE model was trained with unipolar EGMs to acquire encoded features, which were then input into a classifier model. The classifier was combined with atrial positions using one-hot encodings as the ground truth. The optimal architecture was selected through a grid search involving different layer numbers, sizes, and fine-tuning. For the encoding part, we assessed the negative evidence lower bound (ELBO) and Pearson’s correlation. Regarding the classifier, we evaluated accuracy, extended accuracy (indicating accuracy in predicting the region or an adjacent one), and the area under the curve (AUC). Results The best-performing autoencoder architecture presented a negative ELBO of -0.087 and a Pearson’s correlation of 0.971; and the classifier obtained an accuracy of 38.1%, an extended accuracy of 75.2%, and an AUC of 0.814. Conclusion We introduced an alternative method for localizing intracardiac catheters within the atrial chambers based on deep-learning techniques. In contrast to traditional hardware technologies, our proposed method eliminates the need for external magnetic or impedance reference patches. This approach is not limited to AF and can be extended to other supra-ventricular procedures. The results of our proposed method are promising, suggesting potential advancements in alternative systems for locating intracardiac catheters to complement existing classical hardware methods in the future.Variational autoencoder architecture

Left ventricular wall thickening predicts left atrial low voltage areas in patients undergoing catheter ablation for atrial fibrillation

Abstract Background The success rate of circumferential pulmonary vein isolation (CPVI) remains suboptimal in patients with paroxysmal and persistent atrial fibrillation; moreover, the detection of low voltage areas (LVA) in the left atrium does predict an even higher recurrence rate of atrial tachyarrhythmias after the procedure. Left ventricular wall thickening (LVWT) is known to correlate with left atrial volume; however, no data is available whether LVWT is predictive of the presence of left atrial LVA. Purpose The aim of this study was to investigate whether LVWT is predictive of left atrial LVA and to verify that the presence of LVA confer a higher arrhythmia recurrence rate after catheter ablation for atrial fibrillation. Methods A total of 374 patients who undervent CPVI with the use of 3D electroanatomical mapping system as a primary procedure were enrolled in the study. Transthoracic echocardiography was performed in all patients prior the procedure with measurement of the thickness of the septum and the posterior wall. Patients were classified based on LVWT as normal (females:≤9mm, males:≤10mm), borderline (females:10-11mm, males: 11-12mm) and increased (females:≥12mm, males:≥13mm). A detailed left atrial voltage map was obtained in all patients prior to ablation with the identification of LVA (bipolar voltage <0.5mV with an area >5cm2). Arrhythmia recurrence was defined as documented atrial fibrillation or atrial tachycardia lasting for at least 30 seconds. Results Among 374 patients (mean age: 59.0±10.2 years, 131 females) 94, 195 and 85 were considered to be normal, borderline and increased based on LVWT, respectively. LVA were found in 29.9% (112/374) of patients. According to LVWT, LVA were detected in 16.0% (15/94), 31.3% (61/195) and 42.4% (36/85) in patients with normal, borderline and increased wall thickness, respectively, p=0.005. Patients with left atrial LVA had a higher [60.7% (68/112)] arrhythmia recurrence compared to those without low voltage areas [35.1% (92/262)] during a mean follow-up of 2.1±1.9 years, p<0.0001. Conclusions Left ventricular wall thickening predicts the presence of left atrial low voltage areas in patients undergoing catheter ablation for atrial fibrillation. Low voltage areas confer a higher arrhyhtmia recurrence rate during follow-up.

Electrophysiologic characteristics and outcomes of atrial tachycardia ablation after mitral valve surgery

Abstract Background Atrial tachycardia (AT) is a commonly encountered rhythm disorder in patients with mitral valvular (MV) surgery. Radiofrequency (RF) ablation is the preferred therapeutic option in symptomatic patients. Purpose We aimed to evaluate the characteristics and ablation outcomes of AT in patients with previous mitral valve (MV) surgery. Methods A total of 100 symptomatic patients [mean age: 56 ±12, gender: 56 (56%) female] with documented AT were enrolled. Activation mapping was performed during tachycardia in all patients as well as entrainment mapping when needed. Voltage mapping was performed in sinus rhythm in the related atrium. Low voltage areas and signals with continuous-fragmented morphology were also tagged. Results In 127 procedures, a total of 158 ATs were documented [59 (37.3%) ATs were right-sided, 95 (60.1%) ATs were left-sided and 4(2.5%) AT was biatrial]. Mean number of ATs per procedure was 1.2±0.6. Macroreentry was the primary mechanism in right and left atrium (83.1% and 63.1%, respectively). Cavo-tricuspid isthmus (CTI) dependent macroreentry was the most frequent mechanism in right ATs whereas perimitral reentry was the most common mechanism in left ATs. Atrial low voltage zones comprised 45.5±25.1 % of total left atrium. The acute procedural success was 95.2%. Freedom from ATa after index procedure was 80% at 12 months and 65.6 % at 24 months. After multiple procedures, freedom from ATa was 77% during the mean follow-up duration of 39.7 ± 27.2 months. Conclusion Left ATs are more common compared to the right ATs and macroreentry is the major mechanism in both right & left ATs. RF ablation of ATs has favourable long-term outcomes in patients with MV surgery.

Optimized workflow for pulmonary vein isolation using very high power short duration radiofrequency ablation

Abstract Background Point-by-point radiofrequency ablation is the most used invasive treatment of atrial fibrillation (AF). However, single-shot technologies are largely widespread due to their proved safety and efficacy. QDOT MICRO (QDM) is a novel contact force–sensing catheter optimized for temperature-controlled radiofrequency (RF) ablation that allows to maintain target temperature during 90 W ablations for ≤4 seconds. Purpose This study evaluates procedural safety and effectiveness as well as long-term effects of an optimized procedural workflow using QDM catheter to perform wide atrial circumferential ablation in patients with paroxysmal AF. Methods Consecutive patients referred for paroxysmal AF first ablation through pulmonary vein isolation (PVI) were prospectively enrolled. Every procedure was performed in general anesthesia by using CARTO3 Electroanatomical Mapping System BiosenseWebster QDM catheter and Deflectable Sheet VIZIGO as single sheet in left atrium. VHPSD was performed to encircling the posterior wall, while conventional-power temperature-controlled (CPTC) mode was used to encircling the anterior wall. The primary safety endpoint was incidence of primary adverse events within ≤7 days of ablation. The primary effectiveness endpoint was freedom from documented atrial tachyarrhythmia recurrence and acute procedural, repeat ablation, and antiarrhythmic drug failure. Results 120 enrolled participants (61 ± 12 years, 45% female) met eligibility criteria. Median procedural skin-to-skin time and RF application for ablating PVs were 56 and 17 minutes, respectively. Median ablation time was 22 minutes. First-pass isolation (entrance and exit block validation) was obtained in 98 % and inter-lesion distance was 4,8 ± 0,8 mm. In 100% of patients PVI was obtained without adverse events. The Kaplan-Meier estimated 12-month rate for clinical success (freedom from symptomatic recurrence of AF) was 93%, freedom from AF was 89% Conclusions PVI performed with point by point optimized workflow using VHPSD RF catheter in combination with steerable sheet is highly efficient and effective without compromising safety.

Single-centre experience with an electrogram-based artificial intelligence software system to identify drivers in pulsed field ablation of persistent atrial fibrillation

Abstract Background Ablation of persistent atrial fibrillation (AF) beyond pulmonary vein isolation (PVI) remains challenging, despite increasing numbers of eligible patients. Previous studies suggest a possible role for non-PVI lesions targeting atrial drivers, but their identification can be difficult and subject to inter-operator variability. Purpose We investigated feasibility for an electrogram-based artificial intelligence software system to assist in the identification of left or right atrial dispersion sites as ablation targets for persistent AF using the penta-spline multi-electrode pulsed-field ablation (PFA) catheter, a recent technique which is more conventionally employed for PVI. Methods This is a single-centre retrospective descriptive study of a cohort of patients with persistent AF, who underwent their first-time ablation from May to November 2023 using the Farawave PFA catheter (Boston Scientific) and the VX1 system (Volta Medical). This system relies on off-line pre-training of multiparametric machine learning algorithms on a database of annotated AF intracardiac electrograms. It connects to cardiac electrophysiology recording systems via a custom data cable to receive analogue data and digitize them through an integrated converter. Its algorithms analyse signals in the cardiac chamber of interest to adjudicate the local presence or absence of dispersion and provides relevant visual cues to operators in order to target energy delivery. Results We identified 16 patients who underwent PFA for persistent AF (long-standing in 5/16, 31.3%), including PVI and further ablation guided by VX1. See table 1 for baseline population characteristics and table 2 for procedural characteristics. All underwent ablation with uninterrupted anticoagulation, general anaesthesia, use of the Rhythmia electroanatomic mapping system and its Orion mapping catheter (Boston Scientific) to feed signals into the VX1 system. VX1-guided electrogram localization and ablation mostly targeted the anterior region of the left atrium (16 segments), followed by its septal region (6 segments) and its lateral region (4 segments); the median number of applications per procedure was 88 [IQR 68-108], including a median of 76 [61-85] in the left atrium and 12 [0-15] applications in the right atrium. The median procedure duration was 123 [114-137] minutes; the median fluoroscopy time was 32 [26-40] minutes and the median radiation dose was 12.5 Gy∙cm2 [10.0-25.8]. Sinus rhythm was restored either during ablation or by electrical cardioversion (see Table 2). Two complications occurred one femoral arteriovenous fistula requiring stenting and one tamponade requiring drainage. At a three-month follow-up, 87.5% did not present AF recurrences. Conclusion Real-time detection and annotation of electrograms to track dispersion using AI-assisted technology to support PFA with a multipolar catheter is feasible. The interest of the approach should be validated by further studies.Table 1.Table 2.

Optimizing ablation sites in recurrent atrial fibrillation cases: a novel approach using emphasize settings

Abstract Backgrounds Although catheter ablation techniques for atrial fibrillation (AF) have advanced, a certain number of cases of re-conduction after pulmonary vein isolation (PVI) still exist and are the most common cause of recurrence of atrial tachyarrhythmias. In some cases, the diversity of anatomical wall thickness and fiber orientation around the PVs might contribute to re-conduction. Identification of optimal target ablation site of re-conduction could reduce unnecessary ablation and decrease the risk of complications. However, in cases where local electrograms consisted with far filed and near filed potentials were coexist, conventional activation mapping with bipolar electrograms sometimes fails to identify the re-conduction sites. Purpose We investigated the utility of using the Emphasize settings in the emphasis map obtained by combining activation mapping and peak frequency mapping in the EnSite X system to determine the optimal ablation sites compared to the conventional map based on the activation mapping. Methods Patients undergoing AF ablation of PVI with the EnSite X system who had recurrent cases or had PVI re-conduction at the initial ablation were included. We retrospectively analyzed the cases from January 2022 to November 2023. In all cases, bipolar voltage and activation maps for left atrium and PVs were obtained by a 16-pole grid catheter (Advisor HD Grid) during atrial pacing or sinus rhythm. Local activation timing and peak frequency maps of the left atrium were performed to obtain the Emphasize settings indicating the optimal ablation sites (E-group). The Emphasize settings obtained from the maps were adjusted to make the site of re-conduction most apparent (Figures). Another group determined the ablation sites based on the activation mapping (A-group). The clinical backgrounds, laboratory data, and echocardiography data were also evaluated. Intravenous administration of ATP was performed in all targeted PVs after successful re-isolation of PVs. Results Total 44 patients (69±10 years, 32 males) and 90 PVs were found to be re-conducted and analyzed. The gaps of 34 and 40 points of PVI were observed in the E-group and C-group, respectively. The number of needs for the ablation points to successful elimination of gap was markedly smaller in the E-group (1.3±0.7 vs. 6.2±3.2, p<0.001). The optimal Emphasize settings was 340 ±75 Hz in the E-group. None of the cases showed dormant conductions by ATP administration in both groups. There were no differences in age, gender, left atrial volume index, left ventricular ejection fraction, serum creatinine levels, and N-terminal pro-brain natriuretic peptide levels between the two groups. Conclusion The optimal ablation site was visualized by adjusting the Emphasize settings, and the number of ablation points to re-isolation of PV might be markedly reduced.

Prevalence of non pulmonary vein triggers and pulmonary pressure change in atrial fibrillation ablation for cardiac amyloidosis patients

Abstract Background Cardiac amyloidosis (CA) has been associated with an increased risk of atrial arrhythmias and high risk to develop pulmonary hypertension due to infiltration of the amyloid protein in the atrial wall. Though non-PV triggers are commonly seen in left atrium, they are also seen in the right side of the heart, so identifying them at the time of ablation is essential. Objective The study evaluates the prevalence of non-PV triggers during catheter ablation in atrial fibrillation (AF) patients affected by cardiac amyloidosis and how restoration of sinus rhythm affects pulmonary pressures. Methods This is a study including 74 consecutive patients with an established diagnosis of amyloidosis ATTR diagnosed with cardiac MRI or myocardial biopsy that underwent their first AF catheter ablation. All have a transthoracic echocardiogram before ablation. They underwent pulmonary vein (PV) isolation + isolation of left atrial posterior wall and superior vena cava. Additionally, extrapulmonary triggers, which are defined as ectopic triggers originating from sites other than PVs including left atrial appendage (LAA), coronary sinus (CS), interatrial septum, crista terminalis, mitral valve anulus were identified. Post procedure, patients were followed up routinely with ECG during office visits, echocardiogram, 7-day Holter monitor and event recorders during the first year followed by biannual checkups during the remaining part of the follow-up period. Student’s t-test was used to compare pulmonary pressure between the groups. Results Isoproterenol-challenge revealed non-PV triggers in 51 (68.9%) patients. These triggers were mostly mapped to LAA (39, 52.7%), CS (30, 40,5%), and crista terminalis (35, 47.3%). Besides, ectopic beats were seen originating from inter-atrial septum (19, 25.6%), mitral valve annulus (10, 13.5%). More than one trigger was found in (68%) patients. At 1-year after the ablation, 65 (87.8%) were arrhythmia-free off antiarrhythmic drugs. Moreover, in patients who maintained sinus rhythm post-ablation, there was either a non progression or a reduction in pulmonary pressures (PAPm before ablation: 44.8 ± 8.9 mmHg vs PAPm after ablation 45.1 ± 11.1 mmHg, P value =0.87). Conversely, those experiencing arrhythmic recurrences demonstrated an increase in pulmonary pressures (PAPm before ablation: 41.9 ± 7.7 mmHg vs PAPm after ablation 47.8 ± 10.2 mmHg, P value =0.019). Fig.1 Conclusion Our findings suggest that non-PV triggers are highly prevalent in cardiac amyloidosis AF patients including a high rate crista terminalis firing. Notably, restoration of sinus rhythm post-ablation was linked to stable or reduced pulmonary arterial pressures, whereas patients with arrhythmic recurrences experienced a significant increase.

Characterization of conduction recovery and atrial electrophysiological properties after pulmonary vein isolation using pulsed field ablation

Abstract Background Pulsed field ablation (PFA) is a relatively new technology for isolation of pulmonary veins in patients with atrial fibrillation (AF). Data addressing reasons for recurrent atrial fibrillation despite primarily successful pulmonary vein isolation (PVI) using PFA are scarce, due to an up to date limited number of patients treated this way. Objective The aim of this study was to analyze electrophysiological characteristics of reconduction and / or left atrial substrate of patients referred to our center for Re-Do procedures for recurrent AF after an initial PVI using PFA. Methods 90 patients (mean age 66±9 years, 69 male (77%)) had been treated in our center from November 2021 to July 2023 with PVI using PFA. 9 (10%) of these patients were referred for Re-Do procedures. These were performed by radiofrequency ablation (RFA) using Carto system including high density mapping and high power / short duration (HPSD) ablation. We analyzed location of PV reconnection and low voltage areas (LVA) in the left atria. Results 7 out of 9 patients (77%) presented with reconnections of pulmonary veins. In one patient a single vein showed reconduction (RSPV), in 5 patients 2 veins were conducting (1x LSPV, 3x LIPV, 1 left sided common os (LCo), 1x RSPV, 3x RIPV). None of the patients showed 3 or 4 reconnected veins. Areas of reconduction in each vein were: LSPV 1x ridge, 1x posterior; LIPV 1x posterior, 1x anterior and posterior; LCo 1x posterior, RSPV 1x anterior, 2x carina, 1x anterior and posterior; RIPV 1x complete, 2x carina. In 7 patients a fibrotic atrial cardiomyopathy (FACM) was diagnosed via high density mapping of LVA’s. In 2 of these patients all 4 pulmonary veins were chronically isolated after the initial PVI. All patients except one (very small anterior LVA) with FACM ≥1 were treated with additional linear or encircling lesions according to the individual extent of the fibrotic areas. 2 patients had no LVA’s detectable. In one of those 2 patients 2 veins had reconnected. The other patient had chronically isolated veins (no proof of dormant conduction with adenosine) and no detectable non-PV-triggers under isoprenaline. Conclusion In the population of patients undergoing PVI using PFA in our center, only 10% had clinically relevant recurrences leading to the necessity of a Re-Do procedure. Most patients (77%) in this setting had reconnections of pulmonary veins. There is a tendency of posterior reconnections of the left pulmonary veins and reconnections of the carina of the right pulmonary veins, but the number of patients is too small to clearly define predilection sites that have to be paid attention to when using PFA. Additionally, left atrial substrate is an important problem in patients with recurrent AF despite primarily successful PVI and has to be considered and thoroughly addressed in Re-Do procedures.Reconnection of LSPV and anterior LVAAblation of RSPV and LSPV (posterior)

Clinical and electrophysiological characteristics and long term outcomes of catheter ablation for right and left atrial tachycardias

Abstract Background Atrial tachycardias (AT) are complex supraventricular tachycardias which are refractory to antiarrhythmic drugs that require catheter ablation. Purpose In this trial, we aimed to evaulate the outcomes of catheter ablation in patients with symptomatic atrial tachycardia, define the acute procedural success and the recurrence rates in long-term follow-up and determine the clinical and electrophysiological features that affect these outcomes. Methods A total of 666 [mean age: 55 ±16, gender: 344 (51.7%) female] symptomatic patients with AT were enrolled. Prior catheter or surgical ablation history for ATa was present in 199 (29.9%) and 18 (2.7%) of these patients, respectively. Activation mapping was performed during tachycardia in all patients as well as entrainment mapping when needed. Voltage mapping were performed in sinus rhythm in both atriums, late potential mapping was also performed in some patients. Low voltage areas and signals with continuous-fragmented morphology were tagged. Results Macroreentry was the primary mechanism in right and left atrium (70.2% and 52.8%, respectively). Cavotricuspid isthmus (CTI) dependent macroreentry was the most frequent mechanism in right ATs and perimitral reentry and roof-dependent macroreentry were the most common mechanisms in left ATs. A total of 59 (7.5%) complications were observed in 780 procedures.(2.1% major and 5.5% minor) Acute procedural success was 95.9%. Freedom from ATa was 72.8 % during a mean follow-up of 39±23 months. Freedom from ATa after index procedure was 82.3% at 12 months and 75.9 % at 24 months. After multiple procedures, freedom from ATa was 90% at 12 months and 86% at 24 months during the follow-up. In multivariate Cox regression analysis, atrial fibrillation (AF) [(HR) 2.43, 95% c(CI) 1.78-3.30; p<0.001] , history of cardiac surgery [(HR) 1.68, 95% c(CI) 1.22-2.30; p=0.001] and moderate to severe tricuspid regurgitation [(HR) 1.47, 95% c(CI) 1.08-2.01; p=0.014] were significant predictors of ATa recurrence. Conclusion Our findings demonstrated that tailored catheter ablation of ATs especially guided by high density mapping has a high acute success rate and favourable long-term outcomes in patients with symptomatic AT episodes.

Functional substrate mapping characteristics during sinus rhythm predicts critical isthmus of scar related atrial tachycardia

Abstract Background Atrial tachycardia (AT) is a common rhythm disorder in patients with underlying atrial scar due to previous atrial surgery or valvular heart disease. Data is scarce about the role of functional characteristics or conduction properties during sinus rhythm that may have role in the critical isthmus (CI) of re-entry. Purpose We aimed to evaluate the relationship between the functional substrate mapping (FSM) characteristics of right and left atrium and the CI of re-entrant ATs in patients with atrial low-voltage areas. Methods A total of 95 [mean age: 57 ± 13, gender: 57 (60%) female] symptomatic patients with history of left and right AT who underwent catheter ablation with 3-D high-density mapping were enrolled. Isochronal late activation mapping were created during sinus/paced rhythm to detect deceleration zones (DZ). After induction of AT, activation mapping was performed in all patients. Results In 95 patients, 96 left-ATs [49 (51%) ATs were macroreentry and 47 (49%) ATs were localized reentry] and 40 right-ATs [24 (60%) ATs were macroreentry and 16 (40%) ATs were localized reentry] were mapped. Atrial low voltage zones comprised 23.3 ± 13.0 % of total right atrium and 33.3 ± 21.2 % of total left atrium. The mean value of bipolar voltage, EGM duration, and conduction velocity during sinus rhythm corresponding to CI of ATs were 0.17 ± 0.10 mV, 121 ± 39 ms, and 0.09 ± 0.06 m/s, respectively. Total number of DZs were 125 and all CIs of reentry were colocalized with DZs detected during FSM. The positive predictive value of DZs to detect CI of inducible ATs is 87.2%. Freedom from ATa was 76.8% at 12 months follow-up. Conclusion Our findings demonstrated the utility of FSM during sinus rhythm to predict the successful termination sites for ATs. These areas displayed continuous-fragmented signal morphology in correlation with the CI of AT detected during activation mapping.

Cardioneuroablation for vasovagal syncope. Results from an EHRA Survey

Abstract Background Cardioneuroablation (CNA) is a recently introduced catheter-based therapy for vasovagal syncope (VVS), involving the modulation of the cardiac autonomic nervous system. Over the past decade, the body of evidence supporting CNA has consistently grown, sparking increased interest, and leading to broader adoption of this novel therapy for VVS treatment. However, several knowledge gaps persist, particularly concerning clinical indications, methodology, and long-term outcomes. Purpose The aim of this survey is to provide a comprehensive overview of the daily utilization of CNA in Europe. Methods and Results Among 204 participants, half reported that they are already performing CNA in their centres. The survey indicated CNA as an emerging therapy, with most centres initiating this treatment within the last two years. A significant majority of those who responded (71%) adopted a systematic approach by targeting ganglionated plexuses (GPs) in both the right atrium (RA) and left atrium (LA) as their first-line approach. The second most common approach (16%) involved performing ablation LA GPs only in the cases where there is no response following RA ablation. Figure 1 shows the GPs usually targeted for ablation. The most frequent procedural endpoint was the increase in the heart rate. Ninety percent of respondents relied on an anatomical approach for GP localization, while 59% also guided the procedure using electrogram analysis. Less frequently used approaches included pre-procedural imaging (20%), high-frequency stimulation (17%), and spectral analysis (10%). Only 11% of physicians discharged patients who underwent CNA without anticoagulation or antiplatelet therapy. In most cases (58%), respondents discharged their patients with anticoagulation, while 28% on single antiplatelet therapy. Overall, CNA is considered an effective procedure (80% of responders rating its effectiveness at or above 70%) and a safe procedure (with an estimated 1% rate of procedure-related complications, with symptomatic sinus tachycardia being the most frequently reported). Conclusions This survey confirmed high expectations for the future of this therapy, as most responders anticipate that CNA will be indicated as a first-line therapy for patients with recurrent cardioinhibitory VVS. Future efforts are necessary to standardize the procedural flow and peri-procedural patient management.

Acute haemodynamic changes during left atrial appendage closure

Abstract Purpose Left atrial appendage closure (LAAC) presents an alternative treatment for stroke prevention in atrial fibrillation (AF) in patients with contraindication for long-term anticoagulation. However, even in patients in AF, left atrial appendage plays an important role in reservoir function of left atrium. The purpose of this study was to assess acute hemodynamic effects during LAAC. Methods Consecutive patients indicated for LAAC from January 2022 to October 2023 were enrolled. The invasive hemodynamic measurements were done at the beginning of the procedure after transseptal puncture, and at the end from the procedure after device deployment. Following parameters were measured: systolic, and diastolic blood pressure, and pressure in left atrium (LA), all measurements were done at rest and after 3 minute isometric exercise (handgrip). Results Thirty-two patients were included (age 76,2+7,1 yrs, 22 (69%) males, 23 (72%) permanent AF, left ventricular ejection fraction 52+11,8%). No patients experienced moderate/severe mitral insufficiency, the saline intake during procedure was 738 ml. Isometric exercise significantly increased the LA pressure: the LA pressures (rest/exercise) were 13.7+6.7 mmHg/16.7+8.8 mmHg (p=0.003) at the beginning of the procedure, and 17.0+7.3mmHg/20.0+7.3 mmHg (p=0.005) after device deployment. The LA pressure obtained after device deployment (both rest/exercise) were significantly higher compared to values obtained at the beginning of the procedure. (p=0.003). Conclusions LAAC is associated acute increase of both rest and exercise LA pressure. Whether its acute negative effect remains over time needs further investigation.

Effect of atrial extrasystoles in electrophysiological properties in heart failure patients

Abstract Background Patients with heart failure (HF) most likely have an extensive arrhythmogenic substrate which increases vulnerability to atrial fibrillation (AF). Conduction disorders underlying this increased AF vulnerability -hidden during sinus rhythm- may be unmasked by spontaneous atrial extrasystole (AES). Objective The aim of this study is to investigate the impact of AES on potential arrhythmogenic electrophysiological properties in patients with HF and AES. Methods Intraoperative epicardial mapping of the right and left atrium (RA, LA), Bachmann’s bundle (BB) and pulmonary vein area (PVA) was performed in 132 patients (10 with HF and 122 without HF). Differences in unipolar potential morphologies and conduction disorders during SR and spontaneous AES were determined. Results A median of 1 (1–3) AES per patient were included. In patients with HF, AES were associated with lower median potential voltages (1.94mV versus 4.02mV, P<0.001), more low voltage areas (10.98% versus 4.97%, P=0.004) and a higher number of short double potentials (28.5% versus 13.0% of short double potentials, P<0.001) compared to patients without HF. Comparing differences (AES - SR) in parameters between patients with and without HF, there was a larger increase in long double potentials (+5.32% versus +0.31%, P<0.001), fractionated potential (+4.18% versus +0.49%, P=0.001), conduction block (+3.39% versus +0.63%, P=0.002) and continuous conduction delay and block (+6.72% versus +1.74%, P=0.001) in HF patients. Conclusions In HF patients, AES cause lower unipolar potentials voltages and more conduction disorders than in patients without HF. Differences in arrhythmogenic properties between sinus rhythm and atrial extrasystoles are more pronounced in HF patients. These results suggest that HF patients have hidden arrhythmogenic substrates that can be uncovered by AES and may explain the increased AF vulnerability.

Predictive value of guideline-referred risk scores in estimating left atrial low voltage areas and recurrence of atrial fibrillation in repeat ablation procedures

Abstract Background Despite advances in mapping and ablation techniques, atrial fibrillation (AF) recurrence remains a challenge after pulmonary vein isolation. Low voltage areas (LVA) in the left atrium are associated with higher recurrence rates after left atrial ablation. Risk scores for evaluating post-ablation recurrences are not well established, although a better patient selection for repeat procedures would be of great help in clinical practice. Purpose Risk scores for prediction of AF recurrence have not been tested in a cohort of repeat ablations. Methods This single-center study includes consecutive patients from the prospective Bernau ablation registry undergoing ultra-high-density (UHD) mapping and repeat ablation for AF/AT recurrence between 2016 and 2020. The potential of seven guideline mentioned risk scores (APPLE, DR-FLASH, MB-LATER, ATLAS, CAAP-AF, BASE-AF 2, ALARMEc) to predict (1) AF/AT recurrence beyond a three-months blanking period after repeat left atrial ablation (Re-PVI ± further LA ablation) and (2) the percentage of left atrial LVA in UHD mapping was investigated. LVA were defined as sites with a bipolar peak-to-peak voltage of <0.5 mV with an extent of >1cm². Optimal cutoff for sensitivity and specificity for LVA and AF/AT recurrence as endpoint was chosen using C statistics with receiver-operator characteristics (ROC). Further ROCs were performed to illustrate the predictive ability of the scores. Pearson correlation was used to test associations between variables. Results 160 patients (mean age 67.9 ± 9.1 years, 60.6% persistent AF, mean AF duration 4.6 ± 3.8 years) with complete left atrial UHD mappings (mean EGMs 9754 ± 5808) were included. Overall recurrence rate over a mean follow-up time of 16 ± 11 months was 55.6%. The predictive value of the investigated risk scores on AF/AT recurrence in our cohort was low (Table 1), with the highest power for CAAP-AF (p = 0.015, AUC = 0.615) and DR-FLASH score (p = 0.040, AUC = 0.594), Figure 1. With respect to left atrial LVA we found a better predictive power for the CAAP-AF (p < 0.001, AUC 0.702), APPLE (p < 0.001, AUC 0.687), DR-FLASH (p < 0.001, AUC 0.688), ATLAS (p = 0.005, AUC 0.634) and ALARMEc (p = 0.007, AUC 0.608) score to predict low voltage based on a calculated cut-off of 22% of total left atrial surface (Figure 1). Conclusion The predictive value of guideline-referred risk scores in estimating AF/AT recurrence after repeat ablation is low and does not seem to be of relevant help in patient selection for further interventional treatment. Some scores demonstrate a fairly good prediction for the amount of left atrial LVA and therefore might help in choosing the right mapping and ablation regime beforehand.

Factors associated with early postoperative mortality after total anomalous pulmonary venous connection repair: A retrospective cohort study.

Total anomalous pulmonary venous connection (TAPVC) is a rare congenital defect where pulmonary venous plexus fails to connect with the left atrium (LA). Surgical repair is the primary treatment for TAPVC, but factors influencing outcomes are not fully understood. This study investigates the early outcomes of surgical repair for TAPVC and associated factors. A retrospective cohort analysis was conducted on TAPVC patients who underwent surgical repair between 2012 and 2022. Data were collected from medical records and supplemented with phone call validation. Demographic characteristics, surgical data, diagnostic tests, and outcomes were analyzed. Statistical analysis included chi-square, t-tests, and multivariate logistic regression using SPSS. A total of 88 patients underwent surgical repair for TAPVC, resulting in a mortality rate of 21.6%. Weight and bypass time were significantly associated with patient survival. Female patients had a higher likelihood of death. The anatomic type did not significantly influence mortality. Patients with pulmonary venous obstruction (PVO) experienced a higher mortality rate. Notably, ligation of the vertical vein in supracardiac and infracardiac types was associated with lower mortality. In conclusion, our study identifies several key factors contributing to higher mortality rates following TAPVC surgery, including low weight, female gender, prolonged bypass time, and preoperative vein obstruction. Highlighting the significance of surgical technique, particularly the sutureless approach, we advocate for its meticulous consideration to achieve improved outcomes. Furthermore, our findings indicate a potential decrease in mortality associated with vertical vein ligation, which may mitigate the risk of post-repair heart failure. We suggest further rigorous studies to gain comprehensive insights into TAPVC surgical interventions.