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Introduction: Pulsed‐field ablation (PFA) is a novel nonthermal energy that shows unique features that can be of use beyond pulmonary vein ablation, like tissue selectivity or proximity rather than contact dependency. Methods and Results: We report three cases of right focal atrial tachycardias arising from the superior cavoatrial junction and the crista terminalis, in close relationship with the phrenic nerve, effectively ablated using a commercially available PFA catheter designed for pulmonary vein isolation without collateral damage. Conclusion: PFA can be useful for treating right atrial tachycardias involving sites near the phrenic nerve, avoiding the need for complex nerve‐sparing strategies. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to investigate the occurrence, type and correlation of early and late atrial arrhythmias following mitral valve repair in patients with no preoperative history of atrial arrhythmias. Methods: Patients undergoing mitral valve (MV) repair for degenerative disease were included. Early and late postoperative electrocardiograms were evaluated for the incidence and type of atrial arrhythmia (atrial fibrillation [AF] or atrial tachycardia [AT]). Results: The 192 patients were included. Early atrial arrhythmias occurred in 100/192 (52.1%) patients; AF in 61 (31.8%) patients, early AT in 15 (7.8%) and both in 24 (12.5%). In total 89% of patients were discharged in sinus rhythm. During a follow‐up time of 7.3 years, 14 patients (7.3%) died and 49 (25.5%) patients developed late atrial arrhythmias. At 10 years, the cumulative incidence of any late atrial arrhythmia, with death as competing risk, was 64% (95% confidence interval [CI] = 55%–72%). On Fine‐Gray model analysis, only early postoperative AF lasting >24 h was related to the development of late AF (hazard ratio 5.99, 95% CI = 1.78%–20.10%, p =.004). Early postoperative ATs were related to the development of late tachycardias, independent of their duration (<24 h hazard ratio 4.25, 95% CI = 1.89–9.57, p =.001 and >24 h hazard ratio 3.51, 95% CI = 1.65–7.46, p =.001). Conclusions: Early and late atrial arrhythmias were common after MV repair surgery. Only early postoperative AF lasting >24 h was a risk factor for the occurrence of late AF. Conversely, any postoperative AT was correlated to the development of late ATs. [ABSTRACT FROM AUTHOR]

Introduction Methods Results Conclusion Typical atrial flutter (AFL) is a macroreentrant tachycardia in which intracardiac conduction rotates counterclockwise around the tricuspid annulus. Typical AFL has specific electrocardiographic characteristics, including a negative sawtooth‐like wave in the inferior lead and a positive F wave in lead V1. This study aimed to analyze the origin of the positive F wave in lead V1, which has not been completely understood.This study enrolled 10 patients who underwent radiofrequency catheter ablation for a typical AFL. Electroanatomical mapping was performed both during typical AFL and entrainment from the right atrial appendage (RAA). The 12‐lead electrocardiogram (ECG) and three‐dimensional (3D) electroanatomical maps were analyzed.The positive F wave in lead V1 changed during entrainment from the RAA in all the cases. The 3D map during entrainment from the RAA revealed an area of antidromic capture around the RAA, which collided with the orthodromic wave in the anterior right atrium. This area of antidromic capture around the RAA was the only difference from the 3D electroanatomical map of AFL and is considered the cause of the change in the F wave in lead V1 during entrainment.The analysis of the differences in the 12‐lead ECG and 3D maps between tachycardia and entrainment from the RAA clearly demonstrated that activation around the RAA is responsible for the generation of the positive F wave in lead V1 of typical AFL. [ABSTRACT FROM AUTHOR]

Introduction Methods and Results Conclusion Supraventricular tachycardia (SVT) is a common pediatric arrhythmia. Beta blockers (BBs) and calcium channel blockers (CCBs) are used for treatment despite little data examining their use. We describe the prescriptive tendencies, efficacy, and tolerability of BBs and CCBs used in the treatment of pediatric SVT.This is a multicenter retrospective cohort study from three academic children's hospitals. Individuals aged 1–21 years at time of SVT diagnosis initiated on a BB or a CCB between 01/01/2010 and 12/31/2020 were included. Exclusion criteria were pre‐excitation, ectopic atrial tachycardia, and hemodynamically significant heart disease. Demographic, comorbidity, symptomatology, and medication data were collected. Treatment success was defined using a composite data abstraction tool. Of 164 patients, 151 received a BB and 13 received a CCB. The success rate on the initial dosage was 46% for both BB and CCB; the success rate following dosage adjustments was also comparable for BBs (98/151, 65%) and CCBs (9/13, 69%). While 27 (18%) BB patients experienced intolerable side effects, no CCB patient did.Treatment with a BB or CCB was successful in half of patients. BBs were prescribed more frequently than CCBs but were associated with more side effects. [ABSTRACT FROM AUTHOR]

Introduction Methods and Results Conclusion The decremental properties of the nodoventricular pathway (NVP) are uncertain.During short RP supraventricular tachycardia, a His‐refractory premature ventricular contraction (PVC) consistently terminated the tachycardia without atrial capture immediately after the PVC. Whereas a slightly earlier PVC failed to reset the subsequent His but terminated the tachycardia without atrial capture one cycle later.These observations are diagnostic of slow‐fast atrioventricular nodal reentrant tachycardia (AVNRT) with a bystander concealed‐NVP and can be explained by decremental properties in the NVP itself; greater prematurity of the PVC resulted in more decremental conduction over the NVP, causing the AVNRT termination one cycle later. [ABSTRACT FROM AUTHOR]

Introduction: The impact of early recurrence of atrial tachyarrhythmia (ERAT) within the 90‐day blanking period on long‐term outcomes in atrial fibrillation (AF) patients undergoing cryoballoon ablation (CBA) is controversial. This study aimed to assess the relationship between ERAT and late recurrence of atrial tachyarrhythmia (LRAT) post‐CBA. Methods: Utilizing data from a multicenter registry in Korea (May 2018 to June 2022), we analyzed the presence and timing of ERAT (<30, 30–60, and 60–90 days) and its association with LRAT risk after CBA. LRAT was defined as any recurrence of AF, atrial flutter, or atrial tachycardia lasting more than 30 s beyond the 90 days. Results: Out of 2636 patients, 745 (28.2%) experienced ERAT post‐CBA. Over an average follow‐up period of 21.2 ± 10.3 months, LRAT was observed in 874 (33.1%) patients. Patients with ERAT had significantly lower 1‐year LRAT freedom compared to those without ERAT (42.6% vs. 85.5%, p <.001). Multivariate analysis identified ERAT as a potential predictor of LRAT, with a hazard ratio (HR) of 3.98 (95% confidence interval [CI], 3.47–4.57). Significant associations were noted across all examined time frames (HR, 3.84; 95% CI, 3.32–4.45 in <30 days, HR, 5.53; 95% CI, 4.13–7.42 in 30–60 days, and HR, 4.29; 95% CI, 3.12–5.89 in 60–90 days). This finding was consistently observed across all types of AF. Conclusion: ERAT during the 90‐day blanking period strongly predicts LRAT in AF patients undergoing CBA, indicating a need to reconsider the clinical significance of this period. [ABSTRACT FROM AUTHOR]

Introduction: There is a lack of studies in the literature directly investigating the relationship between atrial tachycardia (AT) and left atrial (LA)/left atrial appendage (LAA) thrombus, and current guidelines do not provide strong recommendations regarding the use of transesophageal echocardiography (TEE) before AT catheter ablation. This study aims to elucidate the relationship between AT and the presence of LA/LAA thrombus and contribute to the literature on the use of TEE before AT catheter ablation. Methods: This single‐center retrospective observational study screened patients who underwent TEE between February 10, 2019, and February 10, 2023. Patients were assigned to the AT patient and control groups. TEE was conducted to exclude thrombus in the AT ablation group. The control group included patients who underwent TEE for interatrial septum evaluation and had LA imaging during TEE but did not have atrial arrhythmia. To mitigate bias between the AT patient group and the control group, they were randomized 1:1 using propensity‐score matching (PSM). Following randomization, each group consisted of 49 patients. Results: All analyses were conducted after PSM. There were no statistically significant differences between the AT patient and control groups in terms of baseline clinical characteristics and echocardiographic features. Additionally, no significant differences were found between the blood viscosities calculated at low and high shear rates in both groups. The study revealed a significant difference between the two groups in the presence of LA spontaneous echo contrast (SEC) (24.5% in AT group vs 0% in Control group, p =.001), but not in the presence of thrombi (8.2% in AT group vs 0% in Control group, p =.117). Conclusion: Compared to the control group, the presence of SEC was significantly higher in the AT patient group. The increased frequency of SEC in AT patients suggests the hypothesis that AT may contribute to LA stasis. The routine use of TEE before AT catheter ablation remains controversial, despite the presence of LA thrombus and SEC in the AT patient group. The clinical assessment of thrombus presence before the procedure must be conducted on a patient‐specific basis. [ABSTRACT FROM AUTHOR]

Introduction: The unique safety profile of pulsed field ablation (PFA) has made pulmonary vein isolation (PVI) + left atrial posterior wall (LAPW) ablation promising for treating persistent atrial fibrillation (PerAF). The goal of this study was to assess long‐term freedom from atrial fibrillation, atrial flutter, and atrial tachycardia (AF/AFL/AT), as well as the safety and feasibility of LAPW PFA using multipolar, pentaspline Farawave catheter. Methods: Retrospective observational study at a single institution. Data for 94 patients were collected from a prespecified intraprocedural registry. The long‐term AF/AFL/AT recurrence assessment was based on an analysis of medical history; 24‐h Holter ECGs at 3, 6, and 12 months postablation; and 12‐lead ECGs recorded during symptomatic episodes or visits. Results: Half of the patients had ls‐PerAF, and half had a history of catheter ablation—mostly RF PVI. The acute ablation success rate was 100%, and the primary safety outcome was observed in 2 patients. Fifty patients experienced AF/AFL/AT recurrence (54.3%). An increase in LAPW low‐voltage areas and AF classification were associated with arrhythmia recurrence. After a median follow‐up of 13 months, the Kaplan‒Meier estimated median time free of AF/AFL/AT after a single procedure was 14.7 months. Conclusion: PFA PVI + PWA had the best outcome in perAF patients without extensive LA fibrosis. AF recurrence was paroxysmal in significant part of the cohort. The addition of PWA to PVI using multipolar PFA was safe and did not significantly influence the transpired ablation time. [ABSTRACT FROM AUTHOR]

This article discusses a case of narrow complex tachycardia with alternating atrial activation. The patient had previously undergone an ablation procedure for pre-excited atrial fibrillation but experienced recurrent episodes of palpitations. The article explores the mechanism behind the alternating atrial activation and suggests that it may be due to conduction block across the mitral isthmus. The left lateral pathway was successfully ablated, resulting in the resolution of the tachycardia. Further research and mapping techniques are recommended to improve the accuracy of ablation procedures. [Extracted from the article]

Introduction: Ablation of scar‐related reentrant atrial tachycardia (SRRAT) involves identification and ablation of a critical isthmus. A graph convolutional network (GCN) is a machine learning structure that is well‐suited to analyze the irregularly‐structured data obtained in mapping procedures and may be used to identify potential isthmuses. Methods: Electroanatomic maps from 29 SRRATs were collected, and custom electrogram features assessing key tissue and wavefront properties were calculated for each point. Isthmuses were labeled off‐line. Training data was used to determine the optimal GCN parameters and train the final model. Putative isthmus points were predicted in the training and test populations and grouped into proposed isthmus areas based on density and distance thresholds. The primary outcome was the distance between the centroids of the true and closest proposed isthmus areas. Results: A total of 193 821 points were collected. Thirty isthmuses were detected in 29 tachycardias among 25 patients (median age 65.0, 5 women). The median (IQR) distance between true and the closest proposed isthmus area centroids was 8.2 (3.5, 14.4) mm in the training and 7.3 (2.8, 16.1) mm in the test group. The mean overlap in areas, measured by the Dice coefficient, was 11.5 ± 3.2% in the training group and 13.9 ± 4.6% in the test group. Conclusion: A GCN can be trained to identify isthmus areas in SRRATs and may help identify critical ablation targets. [ABSTRACT FROM AUTHOR]

Introduction: Inappropriate sinus tachycardia (IST) is a common condition with frequently not tolerated beta‐blockers or ivabradine and a high rate of complication in ablation strategy; we describe an alternative anatomical approach of sinus node (SN) modulation. Methods: This retrospective study describes a case series of 6 patients from two centers diagnosed with symptomatic IST undergoing SN ablation. Results: The mean age was 40.6 ± 13.9 years; five of the six patients were female, 100% of patients reported heart palpitations, and 66% reported dizziness, the average heart rate (HR) on a 24‐h Holter was 93.2 ± 7.9 bpm. HR during the first stage of a stress test using a standard Bruce protocol was 150 ± 70 bpm, The average HR on 24‐h Holter postablation was 75 ± 5.6 bpm, the sinus rate HR during stage 1 of a Bruce protocol exercise stress test was 120 ± 10 bpm. Conclusion: This is the first case series reporting the acute and long‐term results of a novel anatomical approach for SN modulation to treat IST targeting the arcuate ridge (AR) under intracardiac echography (ICE) guidance. The novel anatomic ICE‐guided catheter ablation approach aimed to identify the earliest activation at the AR with an extension of RF lesions toward its septal region seems effective and safe to modulate the SN in symptomatic patients with IST refractory to medical treatment. [ABSTRACT FROM AUTHOR]

Background: The efficacy and safety of adjunctive low‐voltage area (LVA) ablation on outcomes of catheter ablation (CA) for atrial fibrillation (AF) remains uncertain. Methods: PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) comparing CA with versus without LVA ablation for patients with AF. Risk ratios (RR) with 95% confidence intervals (CI) were pooled with a random‐effects model. Our primary endpoint was recurrence of atrial tachyarrhythmia (ATA), including AF, atrial flutter, or atrial tachycardia. We used R version 4.3.1 for all statistical analyses. Results: Our meta‐analysis included 10 RCTs encompassing 1780 patients, of whom 890 (50%) were randomized to LVA ablation. Adjunctive LVA ablation significantly reduced recurrence of ATA (RR 0.76; 95% CI 0.67−0.88; p <.01) and reduced the number of redo ablation procedures (RR 0.54; 95% CI 0.35−0.85; p <.01), as compared with conventional ablation. Among 691 (43%) patients with documented LVAs on baseline substrate mapping, adjunctive LVA ablation substantially reduced ATA recurrences (RR 0.57; 95% CI 0.38−0.86; p <.01). There was no significant difference between groups in terms of periprocedural adverse events (RR 0.78; 95% CI 0.39−1.56; p =.49). Conclusions: Adjunctive LVA ablation is an effective and safe strategy for reducing recurrences of ATA among patients who undergo CA for AF. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 38-year-old woman with recurrent palpitations and no structural heart disease, who presented with a documented wide QRS complex tachycardia (WCT) with negative precordial concordance. It discusses the differential diagnosis of the tachycardia mechanism and the management approach, including electrophysiologic study and radiofrequency ablation.

The article presents a case study of a 62-year-old female patient with irregular tachycardia. Topics discussed include the differential diagnoses of narrow QRS tachycardias such as atrial flutter and orthodromic reciprocating tachycardia, the results of the 12-lead electrocardiogram administered to the patient, and the clinical implications of regularly irregular tachycardia.

Introduction: Despite advancements in implantable cardioverter‐defibrillator (ICD) technology, sudden cardiac death (SCD) remains a persistent public health concern. Chagas disease (ChD), prevalent in Brazil, is associated with increased ventricular tachycardia (VT) and ventricular fibrillation (VF) events and SCD compared to other cardiomyopathies. Methods: This retrospective observational study included patients who received ICDs between October 2007 and December 2018. The study aims to assess whether mortality and VT/VF events decreased in patients who received ICDs during different time periods (2007–2010, 2011–2014, and 2015–2018). Additionally, it seeks to compare the prognosis of ChD patients with non‐ChD patients. Time periods were chosen based on the establishment of the Arrhythmia Service in 2011. The primary outcome was overall mortality, assessed across the entire sample and the three periods. Secondary outcomes included VT/VF events and the combined outcome of death or VT/VF. Results: Of the 885 patients included, 31% had ChD. Among them, 28% died, 14% had VT/VF events, and 37% experienced death and/or VT/VF. Analysis revealed that period 3 (2015–2018) was associated with better death‐free survival (p =.007). ChD was the only variable associated with a higher rate of VT/VF events (p <.001) and the combined outcome (p =.009). Conclusion: Mortality and combined outcome rates decreased gradually for ICD patients during the periods 2011–2014 and 2015–2018 compared to the initial period (2007–2010). ChD was associated with higher VT/VF events in ICD patients, only in the first two periods. [ABSTRACT FROM AUTHOR]

Introduction: With the entry of pulsed‐field ablation (PFA) into electrophysiology, new possibilities for ablation of different substrates such as epicardial foci of premature ventricular contractions (PVCs) from coronary venous system (CVS) have been opened. Methods: This article focuses on a case of a 27‐year‐old patient with frequent monomorphic PVCs of epicardial origin, treated by radiofrequency ablation, followed by PFA. Results: After unsuccessful focus ablation through CVS with RFA, successful ablations from the same region with PFA were achieved. Conclusion: This is the first described case of successful ablation of epicardial PVCs using PFA, which we hope will help in defining indications for this novel technology and enhance quality of treatment for patients with different arrhythmias. [ABSTRACT FROM AUTHOR]

Introduction: Despite advanced ablation strategies and major technological improvements, treatment of persistent atrial fibrillation (AF) remains challenging and the underlying pathophysiology is not fully understood. This study analyzed the multiple procedure outcome and safety of catheter ablation of spatiotemporal dispersions (DISPERS) detected by artificial intelligence (AI)‐guided software in patients with long‐standing persistent AF. Methods and Results: The Volta VX1 software was used for 50 consecutive patients undergoing catheter ablation for persistent AF. First, high‐density mapping (78% biatrial) with a multipolar mapping catheter was performed. In addition to pulmonary vein isolation (PVI), ablation of DISPERS was performed aiming at homogenizing, dissecting, isolating, or connecting DISPERS areas to nonconducting anatomical structures. Follow‐up contained regular visits at our outpatient clinic at 1, 3, 6, and 12 months including 7‐day Holter electrocardiograms. Patients were mainly suffering from long‐standing persistent AF (mean AF duration 50.30 ± 54.28 months). Following PVI, ablation of left atrial and right atrial DISPERS areas led to AF cycle length prolongation (mean of 162.0 ± 16.6 to 202.2 ± 21.6 ms after) and AF termination to atrial tachycardia (AT) or sinus rhythm (SR) in 12 patients (24%). No stroke or pericardial effusion occurred; major groin complications (pseudoaneurysm n = 1, atrioventricular fistula n = 1) were detected in two patients. After a blanking period of 6 weeks, recurrence of any atrial arrhythmia was documented in 26 patients (52%). The majority of patients presented with organized AT (n = 15) while AF was present in n = 9 patients and AT/AF was observed in n = 2 patients. Twenty‐two patients underwent reablation. During a mean follow‐up of 363.14 ± 187.42 days and after an average of 1.46 ± 0.68 procedures, 82% of patients remained in stable SR. Conclusion: DISPERS‐guided ablation using machine learning software (the Volta VX1 software) in addition to PVI in long‐standing persistent AF ablation resulted in high long‐term success rates regarding AF and AT elimination. Most arrhythmia recurrences were reentrant AT. After a total of 1.46 ± 0.68 procedures, freedom from AF/AT was 82%. Despite prolonged procedure times complication rates were low. Randomized studies are necessary to evaluate long‐term efficacy of dispersion‐guided ablation using AI. [ABSTRACT FROM AUTHOR]

The QDOT MICRO™ Catheter is a novel open‐irrigated contact force‐sensing radiofrequency ablation catheter. It offers very high‐power short‐duration (vHPSD) ablation with 90 W for 4 s to improve safety and efficacy of catheter ablation procedures. Although the QDOT MICRO™ Catheter was mainly designed for pulmonary vein isolation (PVI) its versatility to treat atrial fibrillation (AF) and other types of arrhythmias was recently evaluated by the FAST and FURIOUS study series and other studies and will be presented in this article. Available study and registry data as well as case reports concerning utilization of the QDOT MICRO™ Catheter for the treatment of cardiac arrhythmias including AF, focal and macroreentry atrial tachycardia, typical atrial flutter by cavotricuspid isthmus block, premature ventricular contractions, and accessory pathways were reviewed and summarized. In summary, the QDOT MICRO™ Catheter showed safety and efficacy for PVI and is able to treat also other types of arrhythmias as is was recently evaluated by case reports and the FAST and FURIOUS studies. [ABSTRACT FROM AUTHOR]

Introduction: Atrial fibrillation and atrial flutter originating from the donor s heart is a commonly reported complication post heart transplant. Atrial tachyarrhythmia originating from the recipient s heart, propagated through recipient‐to‐donor connections, is rare with only few cases reported in the literature; most reported cases from our review occur years post‐transplant. Case: A 47‐year‐old male presented with atrial tachycardia 6 months post heart transplant. Electrophysiologic study demonstrated atrial fibrillation originating from native heart and propagated through atrio‐atrial connections to the donor heart. This arrhythmia was successfully terminated with radiofrequency ablation. Conclusion: Atrio‐atrial connection between recipient and donor can form as early as a few months post heart transplant. Radiofrequency ablation appears to be an effective treatment for atrial fibrillation propagated through donor‐to‐recipient connections. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID‐19) has led to a worldwide pandemic that continues to transform but will not go away. Cardiovascular dysautonomia in postacute sequelae of severe acute respiratory syndrome coronavirus 2 infection has led to persistent symptoms in a large number of patients. Here, we define the condition and its associated symptoms as well as potential mechanisms responsible. We provide a careful and complete overview of the topic addressing novel studies and a generalized approach to the management of individuals with this complex and potentially debilitating problem. We also discuss future research directions and the important knowledge gaps to be addressed in ongoing and planned studies. [ABSTRACT FROM AUTHOR]

Introduction: It would be helpful in determining ablation strategy if the occurrence of perimitral atrial tachycardia (PMAT) could be predicted in advance. We investigated whether estimated perimitral conduction time (E‐PMCT), namely, twice the time between coronary sinus (CS) pacing and the ensuing wave‐front collision at the opposite side of the mitral annulus, correlated with the cycle length of PMAT and could predict future PMAT. Methods and Results: We retrospectively (retrospective cohort) and prospectively (validation cohort) investigated atrial fibrillation patients who had received pulmonary vein isolation (PVI) and in whom left atrial maps had been created during CS pacing. We calculated their E‐PMCT. PMAT was observed either by provocation or during follow‐up in 25, AT other than PMAT was observed in 24 (non‐PMAT AT group), and 53 patients never displayed any AT (no‐AT group) in the retrospective cohort. In the PMAT group of the retrospective cohort, a strong positive correlation was observed between the PMAT CL and E‐PMCT (r =.85, p < 0.001). PMAT was never induced nor observed in patients with E‐PMCT less than 176 ms, and the best cut‐off value for PMAT was 180 ms by receiver‐operating characteristic curve analysis. In the validation cohort of 76 patients, the cut‐off value of the E‐PMAT less than 180 ms predicted noninducibility of PMAT, with a sensitivity of 78.6%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 25.0%. Conclusion: Short E‐PMCT may predict noninducibility of PMAT and guide a less invasive ablation strategy. [ABSTRACT FROM AUTHOR]

Introduction: In patients with prior atrial septal defect (ASD) closure and atrial tachyarrhythmias, transseptal puncture can be challenging. Methods and Results: This case report discusses a 65‐year‐old man who had previously undergone pulmonary vein isolation (PVI) and cavo‐tricuspid isthmus ablation for atrial fibrillation before ASD closure, respectively. He developed atrial tachycardia (AT) and underwent catheter ablation. AT was diagnosed as peri‐mitral flutter and the mitral isthmus (MI) linear ablation via a trans‐aortic approach successfully terminated it. Conclusion: This case demonstrates the feasibility and safety of transaortic MI linear ablation in patients with ASD closure devices or anatomical challenges when transseptal puncture is difficult. [ABSTRACT FROM AUTHOR]

Introduction: Severe transitory episodes of bradycardia with subsequent syncope in children are common, and generally portend a benign prognosis. Rarely, patients may experience prolonged asystolic episodes secondary to significant sinus pauses (SP) or paroxysmal atrioventricular block (AVB). Cardioneuroablation (CNA) is a catheter‐based intervention, used to identify and ablate the epicardial ganglionated plexi (GP), which results in disruption of the vagal‐mediated parasympathetic input to the sinus and atrioventricular node. Objective: Describe the methodology and role of CNA for treatment of pediatric patients with functional AVB or SP. Methods: This is a single‐center, case series study. Patients with SP or AVB, 21 years of age or younger, who underwent CNA between 2015 and 2021 were included. CNA was performed via anatomically guided and high‐frequency stimulation methods. Results: Six patients were included. The median age was 18.9 years (range 12.3–20.9 years), 33% female. Two patients had prolonged SP, two had paroxysmal AVB, and two had both SP and AVB. Four patients had prior syncope. The median longest pause was 8.9 s (range 3.9–16.8) with 11 total documented pauses (range 2–231) during the 6 months pre‐CNA. Post‐CNA, the median longest pause was 1.3 s (range 0.8–2.2) with one documented SP after termination of atrial tachycardia at the 3‐month follow‐up. At 6 months, the median longest pause was 1.1 s (0.8–1.3) with 0 documented pauses. No patients had syncope post‐CNA. Conclusion: CNA may be an effective alternative to pacemaker implantation in pediatric patients with syncope or significant symptoms secondary to functional SP or AVB. [ABSTRACT FROM AUTHOR]

IntroductionThe surface electrocardiography of typical atrioventricular nodal reentrant tachycardia (AVNRT) shows simultaneous ventricular-atrial (RP) activation with pseudo R' in V1 and typical heart rates ranging from 150 to 220/min. Slower rates are suspicious for junctional tachycardia (JT). However, occasionally we encounter typical AVNRT with slow ventricular rates. We describe a series of typical AVNRT cases with heart rates under 110/min.MethodsA total of 1972 patients with AVNRT who underwent slow pathway ablation were analyzed. Typical AVNRT was diagnosed when; (1) evidence of dual atrioventricular nodal conduction, (2) tachycardia initiation by atrial drive train with atrial-His-atrial response, (3) short septal ventriculoatrial time, and (4) ventricular-atrial-ventricular (V-A-V) response to ventricular overdrive (VOD) pacing with corrected post pacing interval-tachycardia cycle length (cPPI-TCL) > 110 ms. JT was excluded by either termination or advancement of tachycardia by atrial extrastimuli (AES) or atrial overdrive (AOD) pacing.ResultsWe found 11 patients (age 20-78 years old, six female) who met the above-mentioned criteria. The TCL ranged from 560 to 782 ms. Except for one patient showing tachycardia termination, all patients demonstrated a V-A-V response and cPPI-TCL over 110 ms with VOD. AES or AOD pacing successfully excluded JT by either advancing the tachycardia in 10 patients or by tachycardia termination in one patient. Slow pathway was successfully ablated, and tachycardia was not inducible in all patients.ConclusionsThis case series describes patients with typical AVNRT with slow ventricular rate (less than 110/min) who may mimic JT. We emphasize the importance of using pacing maneuvers to exclude JT.

Introduction: Atrial tachyarrhythmia recurrence during the blanking period (early ATA) after pulmonary vein isolation (PVI) is associated with an increased risk of later recurrence, but its relationship with pulmonary vein reconduction (PVR) is poorly understood. The objective of the present study was to evaluate the relationship between early ATA and PVR. Second, to provide data on the optimal blanking period by (a) evaluating how the predictive values of ATA for PVR are affected by blanking period duration, and (b) assessing the temporal development in atrial fibrillation (AF) burden. Methods: In this RACE‐AF substudy, 91 patients with paroxysmal AF undergoing PVI randomized to radiofrequency or cryoballoon ablation were included. All patients received an implantable cardiac monitor and underwent a protocol‐mandated repeat procedure after 4–6 months for assessment of PVR. ATA ≥ 30 s. ≤ 90 days after PVI constituted early ATA. Results: PVR was found in 37/54 (69%) patients with early ATA and in 11/37 (30%) patients without (p <.001). The positive predictive value of ATA for PVR was independent of blanking period duration (range 0–90 days). In both patients with and without PVR, AF burden was higher in the first month after PVI, but AF burden from the second month was similar to AF burden after the conventional blanking period. Conclusion: Early ATA indicates PVR, and the positive predictive value is independent of the blanking period duration. Altogether, the results of this study support substantially shortening the blanking period after PVI for paroxysmal AF. [ABSTRACT FROM AUTHOR]

Introduction: Pulsed field ablation (PFA) is a new ablation technology for atrial fibrillation (AF). Data regarding early recurrences of atrial tachyarrhythmia (ERAT) after PFA‐pulmonary vein isolation (PVI) are sparse. Methods: Consecutive patients with symptomatic AF were enrolled to undergo PFA‐PVI. A dedicated catheter delivering bipolar energy (1.9–2.0 kV) was used. Late recurrence (LR) was defined as documented AF/atrial tachycardia (AT) lasting more than 30 s after a 90‐day blanking period. Results: Two hundred and thirty‐one patients (42% female, age 69 ± 12, 55% paroxysmal AF [PAF]) were included in this analysis. Median follow‐up time was 367 days (interquartile range: 253–400). Forty‐six patients (21%) experienced ERAT after a median of 23 days (46% in PAF and 54% in persistent AF [persAF]). Kaplan–Meier estimated freedom of AF/AT was 74.2% at 1 year, 81.8% for PAF, and 64.8% for persAF (p =.0079). Of patients experiencing ERAT, an LR was observed in 54%. There was no significant difference of LR between those who presented with very early ERAT (0–45 days) and those with ERAT (46–90 days) (p =.57). In multivariate analysis, ERAT (hazard ratio [HR]: 3.370; 95% confidence interval [95% CI]: 1.851–6.136; p <.001) and female sex (HR: 2.048; 95% CI: 1.114–3.768; p =.021) were the only independent predictors for LR. Conclusions: ERAT could be recorded in 21% of patients after PFA‐PVI and was an independent predictor for LR. We found no difference in the rate of LRs among patients experiencing ERAT before or after 45 days. [ABSTRACT FROM AUTHOR]

Introduction: Regardless of the catheter ablation (CA) for atrial fibrillation (AF) strategy, the role of early recurrences during the blanking period (BP) is still unclear. Our aim was to evaluate atrial tachyarrhythmias (ATAs) recurrences during the BP after CA with the laser‐balloon (LB) technique. Methods: Consecutive patients undergoing LBCA were enrolled. Primary outcome of the study was the overall crude ATA recurrence rate during the BP. ATA recurrences after the BP and in‐hospital readmissions during the BP were deemed secondary outcomes. Results: Two hundred and twenty‐four patients underwent CA with the LB. Median age was 63.0 (55.5–69.5) years and 74.1% were males. 28.6% were persistent AF patients, and 34.8% of patients were followed up with a loop recorder. 15.6% of patients experienced at least an ATA recurrence during the BP. Male sex, chronic heart failure, persistent AF, and recurrences during the BP were found to be associated with long‐term ATA recurrences. Recurrences during the BP remained associated with the outcome of interest at multivariate analysis (hazard ratio [HR] = 12.393, 95% confidence interval [95% CI] = 3.699–41.865, p <.001). An association over time was found between early and late recurrences, with 73.7%, 45.5%, and 10.8% of patients presenting with recurrences at 1‐, 2‐, and 3‐month follow‐up being free from recurrences after the BP, respectively. 8.0% of patients were readmitted during the BP: 4.5% for AF electrical cardioversion, and 1.8% for CA of other atrial arrhythmias; no redo CA was performed. Conclusion: After adjusting for confounders, ATA recurrences during the BP represent the most significant predictor of ATA recurrences after the BP, regardless of AF pattern. [ABSTRACT FROM AUTHOR]

Introduction: Treatment of recurrent atrial fibrillation (AF) is sometimes challenging due to non‐pulmonary vein (PV) foci. Fractionated signal area in the atrial muscle (FAAM) is a valid predictor of the location of non‐PV foci. FAAM ablation has the potential to decrease the recurrence rate of atrial tachyarrhythmia in patients with recurrent AF. We compared the clinical impact of FAAM ablation for recurrent AF, using 1 year follow up date. Methods: A total of 230 consecutive patients with symptomatic recurrent AF who underwent catheter ablation specifically targeting non‐PV foci as FAAM‐guided ablation (n = 113) and non‐FAAM‐guided ablation (n = 117) were retrospectively analyzed. FAAM was assigned a parameter (peaks slider, which indicates the number of components of fractionated signals), ranging from 1 to 15, indicating the location of the FAAM (1: largest, 15: smallest). FAAM‐guided ablation was performed by ablating FAAM until none inducibility of non‐PV foci. On the other hand, non‐FAAM‐guided ablation was performed via linear ablation, complex fractionated atrial electrogram ablation, superior vena cava isolation, and focal ablation according to the location of the non‐PV foci. The RHYTHMIA system was used to perform all the procedures. The primary endpoints were AF recurrence, atrial flutter, and/or atrial tachycardia. Results: After a 1‐year follow up, freedom from atrial tachyarrhythmia was achieved in 90.3% and 75.2% of patients in the FAAM and non‐FAAM groups, respectively (hazard ratio = 0.438 [95% confidence interval: 0.243–0.788], p =.005). Conclusions: FAAM ablation showed a promising decrease in the recurrence rate of atrial tachyarrhythmia in patients with recurrent AF during a 1‐year follow‐up. [ABSTRACT FROM AUTHOR]

The article describes the case of a 37-year-old male patient with recurrent palpitations for two months and had a history of acute myocardial infarction with proximal left anterior descending occlusion who received conservative management involving antiplatelet and lipid-lowering therapies. Topics include the patient's surface electrocardiography (ECG) which revealed tachycardia in the presence of sinus P waves and his diagnosis of ventricular tachycardia and continuous ventricular capture.

The article describes the case of a 55-year-old man with arrhythmogenic cardiomyopathy with biventricular involvement who was referred for subcutaneous defibrillator (S-ICD) removal and dual chamber implantable cardioverter defibrillator (ICD) implanation. Topics discussed include his left ventricular ejection fraction on echocardiography, his medical therapy, and advantage of antitachycardia pacing (ATP) offered by transvenous ICDs over S-ICDs.

Introduction: Electrophysiological characteristics of epicardial connections (ECs) in atria and pulmonary veins (PVs) are unclear despite their important contributions to atrial fibrillation (AF). Unidirectional conduction associated with source‐sink mismatch can occur in ECs due to their fine fibers with abrupt changes in orientation. We detailed the prevalence and electrophysiological characteristics of unidirectional conduction in the atria and investigated its association with the clinical manifestation of AF. Methods: This study retrospectively reviewed electrophysiological studies and radiofrequency catheter ablation in 261 consecutive patients with AF. Results: Unidirectional conduction was observed during ablation encircling the PVs in eight (3.1%) patients, and all occurred in the suspected (N = 4) or definitively (N = 4) recognized ECs. These ECs included three intercaval bundles, four septopulmonary bundles, and one Marshall bundle, and were first manifested in a second procedure in 6 (75%) patients. The unidirectional property was from PV to atrium (exit conduction) in all intercaval bundles and three septopulmonary bundles, and from atrium to PV (entrance conduction) in the remaining two bundles. Intercaval bundles acted as a limb of bi‐atrial macro‐reentrant tachycardia (50%, three of the six including previous cases). Ablation of the exit outside the PVs, including the right atrium, eliminated ECs in three (38%) patients. All patients remain free from arrhythmia recurrence after a mean 13‐month follow‐up. Conclusion: A unidirectional conduction property was closely associated with the EC, as estimated by histological findings. Recognition of this fact by electrophysiologists may help to clarify mechanisms for AF and atrial tachycardia and guide the creation of efficient and safe ablation lesion sets. [ABSTRACT FROM AUTHOR]

Background: Recurrence rates of atrial fibrillation (AF) remain high even after complete wide area circumferential pulmonary vein isolation (PVI). In recent years adjunct posterior wall isolation (PWI) has been performed in patients with more persistent forms of AF but the benefits remain unclear. Aim: The objective of this meta‐analysis was to evaluate the efficacy of adjunct posterior wall isolation in reducing recurrence rates of AF using cryoballoon ablation (CBA). Methods: We searched PubMed, Google Scholar, Clinicaltrials.gov and Cochrane CENTRAL. We included studies comparing PVI to PVI + PWI in patients with either persistent or paroxysmal AF (PAF) undergoing CBA. After data extraction and quality assessment of the studies, we assessed recurrence rates of atrial tachy‐arrhythmias (AF, atrial flutter, and atrial tachycardia) as well as total ablation time and procedural adverse events. Risk ratio (RR), mean difference (MD), and 95% confidence interval (CI) were calculated using Review Manager. Results: Concomitant PWI exhibited a substantial reduction in the risk of AF recurrence (RR: 0.51; 95% CI: 0.42–0.63, p <.00001), as well as all atrial arrhythmias (RR: 0.58; 95% CI: 0.49–0.68, p <.00001). On subgroup analysis, in patients with only PAF, adjunct PWI resulted in significant reduction in recurrence risk of AF (RR: 0.56; 95% CI: 0.41–0.76, p =.0002) as well. There was no significant difference in adverse events between both groups (RR: 0.90; 95% CI: 0.44–1.86; p =.78), whereas total ablation time was significantly increased in PVI + PWI group (MD: 21.75; 95% CI: 11.13–32.37, p <.0001). Conclusion: Adjunct PWI when compared to PVI alone decreases recurrence rates of atrial fibrillation after CBA of patients with persistent as well as paroxysmal atrial fibrillation. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 69-year-old woman with a wide complex tachycardia (WCT) and a suggestion diagnosis of supraventricular tachycardia (SVT). Examinations showed the correct diagnosis of atrial tachycardia (AT) with the site of origin inside the coronary sinus (CS) ostium that was successfully ablated. No changes were noted in atriohis (AH) interval after ablation.

Introduction: Insertable cardiac monitors (ICMs) are commonly used to diagnose cardiac arrhythmias. False detections in the latest ICM systems remain an issue, primarily due to inaccurate R‐wave sensing. New discrimination algorithms were developed and tested to reduce false detections of atrial fibrillation (AF), pause, and tachycardia episodes in ICMs. Methods: Stored electrograms (EGMs) of AF, pause, and tachycardia episodes detected by Abbott Confirm Rx™ ICMs were extracted from the Merlin.net™ Patient Care Network, and manually adjudicated to establish independent training and testing datasets. New discrimination algorithms were developed to reject false episodes due to inaccurate R‐wave sensing, P‐wave identification, and R–R interval patterns. The performance of these new algorithms was quantified by false positive reduction (FPR) and true positive maintenance (TPM), relative to the existing algorithms. Results: The new AF detection algorithm was trained on 5911 EGMs from 744 devices, resulting in 66.9% FPR and 97.8% TPM. In the testing data set of 1354 EGMs from 119 devices, this algorithm achieved 45.8% FPR and 97.0% TPM. The new pause algorithm was trained on 7178 EGMs from 1490 devices, resulting in 70.9% FPR and 98.7% TPM. In the testing data set of 1442 EGMs from 340 devices, this algorithm achieved 74.4% FPR and 99.3% TPM. The new tachycardia algorithm was trained on 520 EGMs from 204 devices, resulting in 57.0% FPR and 96.6% TPM. In the testing data set of 459 EGMs from 237 devices, this algorithm achieved 57.9% FPR and 96.5% TPM. Conclusion: The new algorithms substantially reduced false AF, pause, and tachycardia episodes while maintaining the majority of true arrhythmia episodes detected by the Abbott ICM algorithms that exist today. Implementing these algorithms in the next‐generation ICM systems may lead to improved detection accuracy, in‐clinic efficiency, and device battery longevity. [ABSTRACT FROM AUTHOR]

Introduction: Use of sodium glucose cotransporter 2 inhibitors (SGLT2i) was associated with a reduction in atrial fibrillation hospitalizations. Therefore, we aim to evaluate the effects of SGLT2i on atrial tachy‐arrhythmias (ATA) in patients with cardiac implantable electronic devices (CIEDs). Methods: All 13 888 consecutive patients implanted with a CIED in two tertiary medical centers were enrolled. Treatment with SGLT2i was assessed as a time dependent variable. The primary endpoint was the total number of ATA. Secondary endpoints included total number of ventricular tachy‐arrhythmias (VTA), ATA and VTA, and death. All events were independently adjudicated blinded to the treatment. Multivariable propensity score modeling was performed. Results: During a total follow‐up of 24 442 patient years there were 62 725 ATA and 10 324 VTA events. Use of SGLT2i (N = 696) was independently associated with a significant 22% reduction in the risk of ATA (hazard ratio [HR] = 0.78 [95% confidence interval {CI} = 0.70–0.87]; p <.001); 22% reduction in the risk of ATA/VTA (HR = 0.78 [95% CI = 0.71–0.85]; p <.001); and with a 35% reduction in the risk of all‐cause mortality (HR = 0.65 [95% CI = 0.45–0.92]; p =.015), but was not significantly associated with VTA risk (HR = 0.92 [95% CI = 0.80–1.06]; p =.26). SGLT2i were associated with a lower ATA burden in heart failure (HF) patients but not among diabetes patients (HF: HR = 0.68, 95% CI = 0.58–0.80, p <.001 vs. Diabetes: HR = 0.95, 95% CI = 0.86–1.05, p =.29; p <.001 for interaction between SGLT2i indication and ATA burden). Conclusion: Our real world findings suggest that in CIED HF patients, those with SGLT2i had a pronounced reduction in ATA burden and all‐cause mortality when compared with those not on SGLT2i. [ABSTRACT FROM AUTHOR]

Introduction: We describe the first case of the use of pulsed‐field ablation (PFA) to treat focal atrial tachycardia (FAT) in a pediatric patient. Methods: An 11‐year‐old girl with obesity was referred to our center for ablation of incessant atrial tachycardia. The earliest atrial activation was shown to be present in the left superior pulmonary vein. Radiofrequency ablation of FAT seems to be associated with a lower success rate and, especially, with a higher complication rate than in adult patients. Results: We performed ablation by means of a novel nonthermal energy source (PFA) that is able to reduce the risk of complications due to injury to anatomic structures surrounding the heart. After the first application, stable sinus rhythm was restored. Conclusions: PFA can be used to treat FAT arising from pulmonary veins in young children as a good alternative to RFA ablation, thereby reducing the risk of potential procedure‐related complications. [ABSTRACT FROM AUTHOR]

Introduction: Cryoablation is being used as an alternative to radiofrequency (RF) ablation for atrioventricular nodal reentrant tachycardia (AVNRT) owing to the lower risk of atrioventricular block (AVB) compared to RF ablation. Junctional rhythm often occurs during successful application of RF ablation for AVNRT. In contrast, junctional rhythm has rarely been reported to occur during cryoablation. This retrospective study evaluated the characteristics of junctional rhythm during cryoablation for typical AVNRT. Methods and Results: This retrospective study included 127 patients in whom successful cryoablation of typical AVNRT was performed. Patients diagnosed with atypical AVNRT were excluded. Junctional rhythm appeared during cryofreezing in 22 patients (17.3%). These junctional rhythms appeared due to cryofreezing at the successful site in the early phase within 15 s of commencement of cooling. Transient complete AVB was observed in 10 of 127 patients (7.9%), and it was noted that atrioventricular conduction improved immediately after cooling was stopped in these 10 patients. No junctional rhythm was observed before the appearance of AVB. No recurrence of tachycardia was confirmed in patients in whom junctional rhythm occurred by cryofreezing at the successful site. Conclusion: Occurrence of junctional rhythms during cryoablation is not so rare and can be considered a criterion for successful cryofreezing. Furthermore, junctional rhythm may be associated with low risk of recurrent tachycardia. [ABSTRACT FROM AUTHOR]

Introduction: Ethanol infusion into the vein of Marshall (EIVOM) is expected to be an adjunctive therapy for mitral isthmus (MI) ablation. Additionally, EIVOM can widely ablate the epicardium via the branches that extend to the left atrial posterior wall (LAPW) and facilitate LAPW isolation. This study aimed to investigate the efficacy and durability of LAPW isolation with EIVOM. Methods: Our cohort consisted of 413 patients with atrial fibrillation (AF) who underwent both LAPW and MI ablations. EIVOM was first attempted in 177 (35%) patients with adequate VOMs. The VOM was infused with 5 mL of ethanol with a double coaxial guiding catheter technique. Both ablations were performed only by radiofrequency ablation (the RF group) in the remaining 236 (57%) patients. Results: EIVOM with 5 mL of ethanol was completely achieved in 106 patients (the EIVOM group). The application duration of LAPW isolation did not differ significantly between the two groups (718 ± 276 vs. 709 ± 288 s; p =.78). LAPW debulking ablation was required in 64/106 (60%) and 176/236 (75%) patients in the EIVOM and RF groups, respectively (p <.05). However, AF‐ or atrial tachycardia‐free survival analyses revealed no significant differences between the two groups (log‐rank p =.70). Among the cases of recurrence, 17 and 38 patients underwent subsequent ablation sessions; LAPW was reconnected in 9/17 (53%) and 25/38 (53%) patients (p =.36) in the EIVOM and RF groups, respectively. Conclusion: EIVOM reduced the number of cases that required LAPW debulking ablation but did not improve the durability of LAPW isolation or clinical outcomes. [ABSTRACT FROM AUTHOR]

Introduction: We describe an unusual case of atrial tachycardia (AT) emanating from the left atrial appendage body (LAA), successfully treated by chemical ablation. Methods: A 66‐year‐old patient with cardiac amyloidosis and history of persistent atrial fibrillation ablation presented poorly tolerated AT with 1:1 atrioventricular nodal conduction at 135/min, despite amiodarone therapy. Three‐dimensional mapping suggested a reentrant AT from the anterior aspect of the left LAA. Results: The tachycardia could not be terminated with radiofrequency ablation. The LAA vein was then selectively catheterized and infused with Ethanol, resulting in immediate termination of tachycardia, without LAA isolation. No recurrence occurred at 12 months. Conclusion: Atrial tachycardias emanating from the LAA that are resistant to radiofrequency ablation may respond to chemical ablation of the LAA vein. [ABSTRACT FROM AUTHOR]

Background: Atrial tachycardia (AT) is a commonly encountered rhythm disorder in patients with underlying atrial scar. The role of atrial late activation mapping during sinus rhythm to predict the critical isthmus (CI) of AT has yet to be systematically evaluated. We aimed to investigate the relationship between the functional substrate mapping (FSM) characteristics and the CI of reentrant ATs in patients with underlying atrial low‐voltage areas. Methods: Patients with history of left AT who underwent catheter ablation with 3D mapping using high‐density mapping were enrolled. Voltage map and isochronal late activation mapping were created during sinus/paced rhythm to detect deceleration zones (DZ). Electrograms with continuous‐fragmented morphology were also tagged. After induction of AT, activation mapping was performed to detect CI of the tachycardia. Atrial tachyarrhythmia (ATa) recurrence was defined as detection of atrial fibrillation or AT (≥30 s) during the follow‐up. Results: Among 35 patients [mean age: 62 ± 9, gender: 25 (71.5%) female] with left AT, a total of 42 reentrant ATs induced. Voltage mapping during sinus rhythm revealed low‐voltage area of 37.1 ± 23.8% of the left atrium. The mean value of bipolar voltage, EGM duration, and conduction velocity during sinus rhythm corresponding to CI of ATs were 0.18 ± 0.12 mV, 133 ± 47 ms, and 0.12 ± 0.09 m/s, respectively. Total number of DZs per chamber was 1.5 ± 0.6, which were located in the low‐voltage zone (<0.5 mV) detected by high‐density mapping. All CIs of reentry were colocalized with DZs detected during FSM. The positive predictive value of DZs to detect CI of inducible ATs is 80.4%. Freedom from ATa after the index procedure was 74.3% during a mean follow‐up of 12.2 ± 7.5 months. Conclusion: Our findings demonstrated the utility of FSM during sinus rhythm to predict the CI of AT. DZs displayed continuous‐fragmented signal morphology with slow conduction which may guide to tailor ablation strategy in case of underlying atrial scar. [ABSTRACT FROM AUTHOR]

Introduction: Recent reports highlighted the role of epicardial connections in the development of biatrial tachycardia circuits. Methods: We reported a case of 60‐year‐old female patient who was admitted with recurrent atrial tachycardia (AT) after endocardial pulmonary vein isolation and anterior mitral line formation. Results: Epicardial activation map demonstrated fragmented continuous potentials at the Bachmann's bundle region with good entrainment response. Epicardial radiofrequency ablation terminated AT with complete block in the anterior mitral line. Conclusions: This case corroborates the data relevant to the role of interatrial connections—specifically Bachmann's bundle—in biatrial macroreentrant ATs and demonstrates that epicardial mapping is an effective method to identify the entire reentrant circuit. [ABSTRACT FROM AUTHOR]

Introduction: Anomalous cardiac veins are not rare and pulmonary vein (PV) isolation for atrial fibrillation (AF) treatment should include these veins. Pulsed‐field ablation (PFA) is a novel technology for AF ablation with excellent efficacy and safety profile. In this case series, we describe our first experience of isolation of anomalous cardiac veins using PFA in patients with AF. Methods: We report a series of patients with congenital anomalies of the cardiac veins and AF, treated with PFA. All patients underwent cardiac computed tomography for procedural planning. Results: We included five patients (four males). Anomalous cardiac veins included a connection of a left common ostium to the coronary sinus, a partial and complete drainage of the right superior PV into the superior vena cava (SVC) with and without additional atrial septal defect, a persistent left SVC and an anomalous posterior PV. All anomalous PVs were isolated using PFA. No phrenic nerve palsy or other complications occurred. PFA of an abnormal right superior PV draining into the distal SVC was possible without affecting the sinus node. After a median of 4 months, four patients were free of recurrence. One patient had recurrent AF and perimitral reentry tachycardia, probably facilitated by PFA in the mitral isthmus region during isolation of an anomalous connection of the left common ostium to the coronary sinus. Conclusions: Using systematic preprocedural imaging and three‐dimensional‐electroanatomic mapping, the currently available PFA system seems well suited, efficient, and versatile for the treatment of AF in patients with anomalous cardiac veins. [ABSTRACT FROM AUTHOR]

Introduction: Incidental left atrial appendage (LAA) isolation may occur during radiofrequency ablation of persistent atrial fibrillation (AF). The study aims to describe the mechanisms and long‐term thromboembolic risk related to incidental LAA isolation. Methods: Patients who experienced incidental LAA isolation after AF ablation were included. Culprit sites where ablation resulted in LAA isolation were identified. Thromboembolic risk despite oral anticoagulation (OAC) was compared to that in a propensity‐matched control group without LAA isolation. Results: Forty‐one patients with LAA isolation, and 82 matched patients without LAA isolation were included. The patient age, ejection fraction, LA diameter, and CHA2DS2‐VASc score were 64 ± 11 years, 55 ± 12%, 45.0 ± 7 mm and 2.62 ± 1.5, respectively. Culprit sites included the LAA base, mitral isthmus, inferior LA, Bachmann′s bundle, coronary sinus, and Marshall vein. After 4.2 ± 3.6 years follow‐up, thromboembolism occurred in 7 of 41 patients (17%) with LAA isolation versus 3 of 82 patients (4%) without isolation (log rank p <.009, HR 5.14, 95% CI [1.32–19.94], p =.02). Patients with and without thromboembolism had similar CHA2DS2‐VASc scores (2.65 ± 1.3 vs. 2.71 ± 0.76, p =.89). Thromboembolism occurred during noncompliance with or temporary discontinuation of OAC in four of the seven patients. Conclusions: Incidental LAA isolation may occur during ablation of atrial arrhythmias in the vicinity of, or even at sites remote from the appendage. Patients with incidental LAA isolation had higher rates of thromboembolism compared to patients without isolation. Since thromboembolism may occur despite prescription for OAC, the risks of LAA isolation must be weighed against clinical benefit and appendage occlusion devices should be considered in vulnerable patients. [ABSTRACT FROM AUTHOR]

The article discusses a patient with short RP tachycardia and concentric atrial activation, it discusses differential diagnoses and analyzing ventricular electrogram patterns. It highlights the importance of analyzing the pattern of ventricular electrograms to interpret responses to maneuvers and suggests that an His refractory ventricular extra stimulus (HRVES) can reset an orthodromic AV re‐entrant tachycardia (ORT) by pulling in the local ventricular activation of an accessory pathway.

IntroductionCardiac sympathetic denervation (CSD) is utilized for the management of ventricular tachycardia (VT) in structural heart disease when refractory to radiofrequency ablation (RFA) or when patient/VT characteristics are not conducive to RFA.MethodsWe studied consecutive patients who underwent CSD at our institution from 2009 to 2018 with VT requiring repeat RFA post-CSD. Patient demographics, VT/procedural characteristics, and outcomes were assessed.ResultsNinety-six patients had CSD, 16 patients underwent RFA for VT post-CSD. There were 15 male and 1 female patients with mean age of 54.2 ± 13.2 years. Fourteen patients had nonischemic cardiomyopathy. A mean of 2.0 ± 0.8 RFAs for VT was unsuccessful before the patient undergoing CSD. The median time between CSD and RFA was 104 days (interquartile range [IQR] = 15-241). The clinical VT cycle length was significantly increased after CSD both spontaneously on ECG and/or ICD interrogation (355 ± 73 ms pre-CSD vs. 422 ± 94 ms post-CSD, p = .001) and intraprocedurally (406 ± 86 ms pre-CSD vs. 457 ± 88 ms post-CSD, p = .03). Two patients had polymorphic and 14 had monomorphic VT (MMVT) pre-CSD, and all patients had MMVT post-CSD. The proportion of mappable, hemodynamically stable VTs increased from 35% during pre-CSD RFA to 58% during post-CSD RFA (p = .038). At median follow-up of 413 days (IQR = 43-1840) after RFA, eight patients had no further VT.ConclusionRFA for recurrent MMVT post-CSD is a reasonable treatment option with intermediate-term clinical success in 50% of patients. Clinical VT cycle length was significantly increased after CSD with associated improvement in mappable, hemodynamically tolerated VT during RFA.

Introduction: Use of a novel magnetic sensor enabled optical contact force ablation catheter has been established to be safe and effective for treatment of symptomatic drug‐refractory paroxysmal atrial fibrillation (AF) but has yet to be demonstrated in the persistent AF (PersAF) population. Methods: PERSIST‐END was a multicenter, prospective, nonrandomized, investigational study designed to demonstrate the safety and effectiveness of TactiCath™ Ablation Catheter, Sensor Enabled™(SE) (TactiCath SE) for use in the treatment of subjects with documented PersAF refractory or intolerant to at least one Class I/III AAD. The ablation strategy included pulmonary vein isolation and additional targets at physician discretion. Follow‐up through 15‐months, including a 3‐month blanking period and 3‐month therapy consolidation period, was performed with cardiac event and Holter monitoring. Primary safety, primary effectiveness, clinical success, and quality of life (QOL) endpoints were analyzed. Results: Of 224 subjects enrolled at 21 investigational sites in the United States and Australia, 223 underwent ablation with the investigational catheter. The primary safety event rate was 3.1% (seven events in seven subjects). The Kaplan–Meier estimate of freedom from AF/atrial flutter/atrial tachycardia recurrence at 15‐months was 61.6% and clinical success at 15 months was 89.8%. Subject QOL significantly improved following ablation as assessed via AFEQT (31.6 point increase, p <.0001) and EQ‐5D‐5L (10.7 point increase, p <.0001) and was met with a 53% reduction in all cause cardiovascular healthcare utilization. Conclusion: The sensor‐enabled force‐sensing catheter is safe and effective for the treatment of drug refractory recurrent symptomatic PersAF, reducing arrhythmia recurrence while improving QOL and healthcare utilization. [ABSTRACT FROM AUTHOR]

The article discusses a quality of cardiovascular implantable electronic device selection that is important but misunderstood. Topics covered include the driving factor of cost to clinicians, the different algorithms and technology of manufacturers, the expansion of leadless pacing, and the potential of a mix and match approach for optimal performance. Also noted is the need for trials on devices matched to patient characteristics.

The article describes the case of a 67-year-old diabetic man with ischemic cardiomyopathy presented with a recurrent defibrillator shock. Topics discussed include medical history of the patient, importance of the introduction of premature ventricular complexes (PVC) during wide complex tachycardias (WCT), and ventriculoatrial (V-A0 responses of the tachycardia.

Introduction: Catheter‐ablation (CA) of consecutive left atrial tachycardias (LAT) can be challenging. Pulsed field ablation (PFA) yields a novel nonthermal CA technology for treatment of atrial fibrillation (AF). There is no data regarding PFA of LAT. This study sought to investigate PFA of consecutive LAT following prior CA of AF. Methods: Consecutive patients with LAT underwent ultrahigh‐density (UHDx) mapping. Subsequent to identification of the AT mechanism, PFA was performed at the assumed critical sites for LAT maintenance. Continuous ablation lines were performed if required and evaluated with pre‐ and post‐PFA HDx‐mapping. Results: Fifteen patients (age 70 ± 10, male 73%) who underwent 3.6 ± 2 prior AF‐CA procedures were included. The total mean procedure and fluoroscopy times were 141 ± 43 and 18 ± 10 min, respectively. All 19 of 19 (100%) LAT were successfully ablated with PFA. Two AT located at the right atria required RF‐ablation. LAT were identified as localized reentry (n = 1) and macro‐reentry LAT (n = 18) and targeted with PFA. All LAT terminated with PFA either to sinus rhythm (9/15) or a secondary AT (6/15 and subsequently to SR); 63% (12/19) terminated with the first PFA‐application. All lines (13 roof, 11 anterior, 1 mitral) were blocked. LA‐posterior‐wall isolation (LAPWI) was successfully achieved when performed (10/10). AF/AT free survival was 80% (12/15) after 153 [88–207] days of follow‐up. No procedure‐related complications occurred. Conclusion: PFA of consecutive LAT is feasible and safe. Successful creation of ablation lines and LAPWI can be achieved in a short time. PFA may offer the opportunity for effective ablation of atrial arrhythmias beyond AF. [ABSTRACT FROM AUTHOR]