Introduction: Pulsed Field Cryoablation (PFCA) is a dual-energy cardiac ablation modality consisting of short-duration ultra-low temperature cryoablation (ULTC) followed immediately by pulsed field ablation (PFA) delivered from the same catheter. It is hypothesized that PFCA may improve contact stability during PFA, while maintaining lesion depth and effectiveness of ULTC. Methods: PARALELL is a first-in-human multicenter study evaluating safety and effectiveness of a novel PFCA catheter and system in patients with persistent atrial fibrillation (PsAF) using the combination of pulmonary vein (PVI) and posterior wall (PWI) isolation. Results: 66 patients were ablated at six sites. Groin hematoma in one patient was the only serious procedure- or device-related adverse event recorded in the study. Per protocol, acute effectiveness was evaluated in 46 patients, including 31 patients with post-hoc analysis of cryogenic energy per lesion. After an average of 21.1 ± 9.3 lesions per patient the rates of PVI and PWI were 95.7% (176/184) and 97.7% (42/43), respectively. The average cryogenic energy per patient was highly predictive of acute isolation success with ROC AUC = 0.944 and 100% rates of both PVI and PWI in 24 patients in the optimal energy cohort. Grade I microbubbles and faint muscle contractions were detected in 1.1% and 0.5% of ablations, respectively. Conclusion: This initial multi-center experience suggests that PFCA can be efficiently performed for PVI and PWI using a single versatile catheter system, with high acute success and good early safety profile. The evaluation of the chronic 12-month effectiveness of PFCA is ongoing.

Introduction: The optimal timing to initiate direct oral anticoagulants (DOACs) after acute ischemic stroke in patients with atrial fibrillation (AF) remains uncertain. Therefore, we performed a meta-analysis comparing early versus later DOAC initiation in this population. Methods: We searched PubMed, Embase, and Cochrane for randomized controlled trials (RCTs) answering this clinical question. We pooled risk ratios (RR) with 95% confidence intervals (CI) for binary endpoints. A restricted likelihood random-effects model was used for all outcomes. Quality assessment and risk of bias were performed according to Cochrane recommendations. Results: We included 6541 patients from three RCTs, of whom 3,270 (49.9%) received early treatment. There were no significant differences in recurrent ischemic stroke (RR 0.80; 95% CI 0.56-1.15; p=0.23), all-cause mortality (RR 0.97; 95% CI 0.81-1.18; p=0.27), and systemic embolism (RR 0.43; CI 0.16-1.11; p=0.08) in the early DOAC compared to delayed initiation groups. Similarly, symptomatic intracranial hemorrhage (RR 0.93; 95% CI 0.44-1.96; p=0.84) and major extracranial bleeding (RR 0.67; 95% CI 0.28-1.59; p=0.36) were non-significantly different between groups. Conclusion: In conclusion, early initiation of DOACs in patients with AF after acute ischemic stroke did not reduce recurrent ischemic stroke and was not associated with increased rates of symptomatic intracranial bleeding.

Background: Low voltage bridge mapping (LVBM) is an approach to AVNRT ablation that has been postulated to facilitate the procedure. In our center, AVNRT ablations were performed with the traditional RF current approach using the CARTO mapping system. The use of LVBM in children has been well described with cryoablation but not with RF. LVBM was introduced in our center in April 2023 and is now routinely used for all AVNRT RF ablations. The aim of this study was to analyze how the introduction of the LVBM influenced the results of the pediatric AVNRT ablations using the RF current. Methods: We analyzed all AVNRT ablations performed between January1,2019, and June30,2024, and compared traditional and LVBM approaches. Results: The study group (LVBM) consisted of 40 and the control group of 61 children. Both groups did not differ significantly regarding age, body weight, and sex distribution. In the LVBM group, the total time of RF applications was significantly shorter, and the number of RF applications was smaller than in the control group. Total procedural time did not differ significantly between the groups. The success rate at 3 months follow-up was higher in the LVBM group but failed to differ statistically. No complications were reported in either of groups. Conclusions: The introduction of the LVBM in RF AVNRT ablations in children allows for limiting the number and time of RF applications required, without prolonging the total procedure time. Our experience shows LVBM can also be effectively used in RF ablations of AVNRT.

Introduction: Intramural ventricular tachycardia (VT) remains a challenge because of the difficulty in accurately localizing its focus from the surface of the myocardium. Methods and Results: An 83-year-old man with non-ischemic cardiomyopathy experienced unstable sustained monomorphic VT. Suboptimal pacemaps in the epi/endocardium and the absence of diastolic or presystolic local electrograms indicated the intramural focus. Despite the very short recording time, the live activation directional mapping (AD) showed a centrifugal activation pattern at the possible exit site of the epicardium. Based on these findings, bipolar ablation was performed between the epi- and endocardium and successfully eliminated the unstable intramural VT. Conclusions: AD is a time-agnostic live directional mapping application that may provide the information of intramural activation apart from the myocardial surface.

Background: Delayed pericardial effusion or pericardial tamponade (PE/PT) is a relatively rare complication of left atrial appendage closure (LAAC) but has serious consequences for affected patients. There are limited data related to delayed PE/PT. The aim of this study was to analyze the incidence and potential risks of delayed PE/PT following LAAC. Methods: Patients with nonvalvular atrial fibrillation who were successfully implanted with LAAC devices from October 2014 to July 2023 were screened retrospectively. Patients were divided into two groups according to whether delayed PE/PT occurred. Univariate and multivariate analyses were used to evaluate the potential risks of delayed PE/PT. Results: A total of 1866 patients with successfully implanted LAAC devices were included. Fifty-two patients were excluded because of missing transesophageal echocardiogram or cardiac CT angiogram data 45 days after the procedure, and 106 patients were excluded because of loss to follow-up. Thirty-seven patients were excluded because of acute PE/PT during perioperative period. Among the remaining 1671 patients, 11 developed delayed PE/PT during the follow-up period (2 Watchman2.5, 2 ACP and 7 LAmbre). Ten of these patients recovered after pericardiocentesis, and one patient required cardiac surgery. Patients with delayed PE/PT had a larger left atrial appendage (LAA) orifice diameter, a higher rate of nitinol plug device use and a lower incidence of systolic heart failure. Univariate and multivariate analyses revealed that the use of a nitinol plug device was associated with delayed PE/PT (OR=1.819 95% CI: 0.757-4.343, P=0.018). A larger maximal LAA orifice diameter was also associated with the occurrence of delayed PE/PT (OR=1.473 95% CI: 1.163-1.866, P=0.001). Conclusion: Delayed PE/PT is a rare complication of LAAC device implantation and is related to the use of a nitinol plug device rather than a nitinol cage device. Patients with larger LAA orifice diameters are at greater risk of delayed PE/PT after LAAC.

Background: High-frequency low-tidal-volume (HFLTV) ventilation is a safe and cost-effective strategy that improves catheter stability, first-pass pulmonary vein isolation, and freedom from all-atrial arrhythmias during radiofrequency catheter ablation (RFCA) of paroxysmal and persistent atrial fibrillation (AF). However, the incremental value of adding rapid-atrial pacing (RAP) to HFLTV-ventilation has not yet been determined. Objective: To evaluate the effect of HFLTV-ventilation plus RAP during RFCA of paroxysmal AF on procedural and long-term clinical outcomes compared to HFLTV-ventilation alone. Methods: Patients from the REAL-AF prospective multicenter registry, who underwent RFCA of paroxysmal AF using either HFLTV+RAP (500-600 msec) or HFLTV ventilation alone from April 2020 to February 2023 were included. The primary outcome was freedom from all-atrial arrhythmias at 12-month follow-up. Secondary outcomes included procedural characteristics, long-term clinical outcomes, and procedure-related complications. Results: A total of 545 patients were included in the analysis (HFLTV+RAP=327 vs. HFLTV=218). There were no significant differences in baseline characteristics between the groups. No differences were observed in procedural (HFLTV+RAP 74 [57-98] vs. HFLTV 66 [53-85.75] min, p=0.617) and RF (HFLTV+RAP 15.15 [11.22-21.22] vs. HFLTV 13.99 [11.04-17.13] min, p=0.620) times. Both groups showed a similar freedom from all-atrial arrhythmias at 12-month follow-up (HFLTV+RAP 82.68% vs. HFLTV 86.52%, HR=1.43, 95% CI [0.94-2.16], p=0.093). There were no significant differences in freedom from AF-related symptoms (HFLTV+RAP 91.4% vs. HFLTV 93.1%, p=0.476) or AF-related hospitalizations (HFLTV+RAP 98.5% vs. HFLTV 97.2%, p=0.320). Procedure-related complications were low in both groups (HFLTV+RAP 0.6% vs. HFLTV 0%, p=0.247). Conclusion: In patients undergoing RFCA for paroxysmal AF, adding RAP to HFLTV-ventilation was not associated with improved procedural and long-term clinical outcomes.

Background SCN5A is the most common susceptibility gene in patients with Brugada syndrome (BrS); however, the interpretation and management of benign or variants of unknown clinical significance (VUS) in SCN5A remains a challenge despite the availability of genetic testing. Objective This study aimed to investigate the relationship between the SCN5A variants and clinical symptoms of BrS patients. Methods We resequenced the SCN5A gene in 239 patients diagnosed with BrS at Hiroshima University Hospital and analyzed the association between the SCN5A variants and clinical features, 12-lead electrocardiography (ECG) parameters, or signal-averaged ECG. Results Overall, 84 SCN5A variants were identified: 55 benign, 7 pathogenic, and 22 VUS . No significant difference in the incidence of previous cardiac events was observed between patients with and without SCA5A benign variants. The female proportion was higher in BrS patients with SCN5A VUS or pathogenic variants. Moreover, the symptomatic proportion was higher in BrS patients with SCN5A VUS or pathogenic variants. Multivariate analyses revealed that the presence of SCN5A VUS or pathogenic variants, longer r-J interval in lead V1, and the presence of fragmented QRS were independently associated with the cardiac events in BrS patients and that positive late potentials, longer LAS40, and lower RMS40 were significantly associated with symptomatic BrS in patients carrying SCN5A VUS. Conclusions The SCN5A VUS or pathogenic variants were found to be independent risk factors for the cardiac events in the BrS patients. In BrS patients with SCN5A VUS, the signal-averaged ECG was the key to risk stratification for cardiac events.

; Introduction: A 22-year-old male with no prior cardiovascular history presented with frequent symptomatic ventricular premature contractions (VPCs) with multiple QRS morphologies despite bisoprolol treatment. Results: The coupling intervals progressively increased from VPC1 to VPC3, and VPC2 was the most frequent (VPC1: 9.3%, VPC2: 30.2%, VPC3: 0.5%). The earliest activation site was identified at the left-right coronary cusp junction. Single ventricular extrastimuli with variable coupling intervals from this site successfully reproduced QRS morphologies identical to VPC 1-3. Conclusion: The findings revealed the utility of unique pace-mapping technique in cases of VPCs with multiple morphologies.

Background Currently, there is no reliable endpoint for the conclusion of atrial fibrillation (AF) ablation. Atrial burst pacing and/or isoproterenol challenge are poor diagnostic tools. A newly proposed Vagal AF Induction Test(VAFIT) uses effective atrial refractory period measurement, simultaneously with extra-cardiac vagal stimulation(ECVS) to study AF inducibility pre and post-ablation. Objective Prospective study in patients submitted to radiofrequency catheter pulmonary vein isolation(PVI) plus cardioneuroablation(CNA) evaluating the VAFIT result before and at the end of the procedure with AF recurrence. Methods Prospective study of 142 patients, 57.5[48.9-70.2] years-old, 71% males, with symptomatic AF (79.6% paroxysmal/20.4% persistent), left atrium diameter of 38.0[35.0-41.2] mm, and left ventricular ejection fraction of 63.0 [62.0-68.2]. VAFIT was considered positive or negative depending on whether AF induction occurred. It was performed at baseline and after PVI+CNA, with a single atrial extra stimulus during ECVS (5s/50Hz/1V/kg up to 70V/Pulse Width=50 µs). Patients were followed for a median of 15.0[7.0-20.0] months. The association of VAFIT-positive status at the end of the procedure with AF recurrence was investigated by univariate and multivariate Cox regression analysis. Results Pre-ablation VAFIT was positive in all cases and became negative in 62.9% of patients. AF recurrence: 18.7% in VAFIT-positive and 5.6% in VAFIT-negative patients(p=0.012). VAFIT-positivity was associated with AF recurrence (HR: 4.56(1.37-15.23,p=0.014). Conclusion A VAFIT-positive status following PVI+CNA was strongly and independently associated with AF recurrence. It remains to be investigated in randomized studies whether achieving VAFIT-negativity at the end of the procedure, as demonstrated in this study, would lead to better clinical outcomes.

Background Atrial fibrillation (AF) is the most common cause of arrhythmia-induced cardiomyopathy. Effective management strategies include medical therapy for rate and rhythm control, catheter ablation (CA), and goal directed medical therapy. Sodium-glucose co-transporter 2 inhibitors (SGLT2i), a novel class of anti-diabetic drugs, have shown a promising impact in reducing cardiovascular events in diabetic and non-diabetic heart failure (HF) patients. It is unclear what impact SGLT2i use may have on AF recurrence following catheter ablation. Aim To evaluate the effects of SGLT2i on preventing AF recurrence following CA and impact on other cardiovascular outcomes. Methods and results We performed a comprehensive literature search through multiple search engines (Pubmed, Scopus, Web of Science, and Cochrane) to include eligible studies using the appropriate keywords until 10th April 2024. Our search yielded nine eligible studies with 16,857 patients. Our analysis reveals a significant reduction in AF recurrence after catheter ablation among patients receiving SGLT2i compared to non-SGLT2i medications (RR = 0.72, 95% CI [0.67, 0.78], P < 0.00001). Additionally, SGLT2i therapy was associated with decreased all-cause hospitalizations and reduced risk of ischemic stroke. However, no significant difference in all-cause mortality was observed between SGLT2i and non-SGLT2i groups. Conclusion Our study found that SGLT2 inhibitors significantly reduced AF recurrence post-CA in diabetic patients. Moreover, SGLT2i use was associated with lowered hospitalization and ischemic stroke risk. Though no significant difference in mortality was noted, the decrease in hospitalization suggests a possible favorable effect on cardiovascular events.

Background: Left bundle branch area pacing (LBBAP) offers physiological pacing with potential advantages over right ventricular (RV) pacing, particularly in children. However, data on LBBAP in pediatric populations are scarce. Objective: This study aimed to assess the feasibility and safety of LBBAP in children by reporting 6 cases done successfully. Methods: Six children (four males, two females), aged 2 to 16 years, underwent LBBAP between December 2022 and January 2024 at the American Univeristy of Beirut Medical Center (AUBMC). The implantation procedure followed established techniques. Baseline characteristics, echocardiographic measurements, and pacing parameters were recorded. Results: All six cases fulfilled the criteria for LBBAP. Successful LBBAP was achieved in all cases. Median weight is 20.5 kg, with three patients under 5 years old. Baseline left ventricular ejection fraction (LVEF) was normal in 4 cases, with two exhibiting 52%. The interventricular septal thickness averaged 4.5 mm. No major complications were encountered during follow-up. Conclusion: Left bundle branch area pacing might be a promising alternative to conventional RV pacing, offering potential advantages over traditional pacing methods. Further research is needed to fully elucidate its efficacy and long-term benefits in pediatric populations.

Background: Radiofrequency(RF) ablation of premature ventricular complexes(PVCs) is a well-established treatment for patients high PVCs burden, even when arising from epicardial/intramural localization. Consistent data about safety of using high power RF is lacking in literature in these regions. Aim: The aim of this study is to investigate safety of different RF power settings, efficacy and outcome of non-endocardial PVCs ablation. Methods: Consecutive patients who underwent PVC ablation were included (2017-2023). We defined “Non-Endocardial Radiofrequency Ablation”(NERA) a procedure in which at least one ablation site has been identified into the cardiac venous system, aortic cusps, inter-leaflet region or pulmonary cusps. Results: Total number of NERA sites was 64 in 53 procedures. In 63% of the procedures, high power (≥40W) and in 60% long duration (≥60 seconds) RF was delivered in at least one site (mean power:37±9W(15-50), mean duration of single RF 88±65 seconds (30-304)). In 21% of the procedures, a combination of both high power and long duration RF applications was performed. Procedural success was achieved in 47 procedures(84%). Only one severe complication (pericardial bleeding) was observed. In 22(39%) procedures, multisite ablation was performed which was associated with procedural failure (OR 7,47;p=0,01). During follow-up, mean and median PVC burden reduction were 69±41% and 96% respectively. Multisite ablation and coronary venous system RF were predictors of recurrence (HR 3.6;p=0.026 and HR 3.85;p=0.014). Conclusion: Ablation from non-endocardial sites is a safe and effective procedure, even using high power and/or long duration RF with clear benefit in terms of PVC burden reduction.

Introduction The docking button of the Aveir leadless pacemaker (LP) is often difficult to access due to its inappropriate position in the right ventricle (RV). Methods and Results We report a case where the Aveir LP was successfully retrieved by releasing the wedged docking button in the inferior wall of the RV using a loop wire technique. Conclusion The loop wire technique may be useful to change the position of the Aveir LP. This may be helpful to retrieve the Aveir LP even in the case where the docking button is wedged in the inferior wall of the RV.

Introduction Implantable loop recorders (ILR) are recommended to detect atrial fibrillation (AF) in cases of cryptogenic stroke (CS). However, the utility of loop recorder for detection of other actionable arrhythmias in these patients is limited. Objective: To evaluate the utility of ILR to detect arrythmias other than AF in patients with cryptogenic stroke. Methods: We enrolled consecutive CS patients referred for an ILR. A retrospective chart review was conducted from 2018 to 2021. All patients were monitored for a minimum of one year. Results: The cohort included 260 consecutive patients with cryptogenic stroke with a mean age of 68. 2 +/- 13.27 years patients of this cohort had at least one actionable arrhythmic event. AF was found in 47 (18%) patients and 44 (17%) patients were found to have other arrhythmias. Out of these 44 patients, 23 patients (9%) were found to have supraventricular tachycardias (SVT), 4 patients (2%) had ventricular tachycardias, 9 patients (3%) had pauses, 8 patients (3%) had significant bradycardia events. Anticoagulation was initiated in all 47 patients with AF. A total of 15 patients (6%) underwent procedures which included 7 pacemakers, 1 implantable cardioverter-defibrillator, 1 SVT ablation, 6 electrophysiology studies because of ILR findings. Conclusion: ILRs can successfully identify AF in patients with cryptogenic stroke. However, there is a high incidence of other arrythmias that can be detected by implanting ILRs that would otherwise would not be identified or have delayed detection. The study demonstrates the advantage of long-term remote monitoring of patients with CS beyond AF detection.

In recent years, the number of patients with implanted leadless pacemaker has increased significantly. Due to the small size of the device, low risk of infection, indications for removal are rare. The dwell time is correlated with extraction difficulty. Although the MICRA TPS contains retrieval feature at the proximal part of the device, the manufacturer (Medtronic) does not offer tools dedicated to this procedure. Complete encapsulation of the device may also make removal difficult or even impossible. We present the case of a patient in whom MICRA TPS was successfully removed 70 months after implantation with non-dedicated commercially available tools.

A 56-year-old man with non-ischemic cardiomyopathy with three prior ablations targeting two different MMVTs presented with recurrent VT. Therefore, he underwent epicardial mapping with adjuvant CT imaging which demonstrated midmyocardial scar. Fractionated potentials noted during mapping in this region, and entrainment suggested inner loop. Interestingly, pacing showed two different QRS morphologies identical to his previously ablated VTs with a long stim-QRS at this region. Epicardial ablation carried on during the VT successfully terminated it, but the VT remained inducible and required endocardial ablation to make it noninducible. The patient has been VT-free for 12 months following this ablation off antiarrhythmic drugs.

Introduction Implantable permanent pacemaker function is supported by their energy sources by a mean period of 8,8 to 12,4 years. We previously published this case of a patient with a normally functioning VVI pacemaker, 31 years after implantation. Methods and Results In this report, we state that the device is still functioning normally 40 years after implantation. The most recent device interrogation revealed pacing threshold of 0.9 V/0.5 ms. Holter monitoring for 24 hours recorded a total of 98.707 beats with 97,78% paced beats, without any indication of pacemaker malfunction and with stable heart rate at 70-71 bpm. Conclusion Most patients with implantable devices have the appropriate follow-up and settings of low energy consumption. Manufacturing companies are mainly considered responsible for achieving prolonged device longevity, focusing on the goal of high energy capacity of future devices.

A 70-year-old man presented with regular wide QRS complex tachycardia (WCT) at a rate of 185 beats/min, characterized by left bundle branch block morphology. WCT termination was achieved through electrical cardioversion. A subsequent 12-lead electrocardiogram revealed sinus rhythm with complete right bundle branch block (CRBBB) morphology. Echocardiography showed normal left ventricular function without structural heart disease. An electrophysiological study was then conducted, followed by catheter ablation. At baseline, the atrio-His and His-ventricular intervals were normal. Fractionated ventricular potentials were observed in the para-Hisian region during sinus rhythm. Neither dual atrioventricular (AV) nodal physiology nor ventriculoatrial conduction was observed during programmed pacing. Clinical WCT was induced by ventricular extra-stimulation with concurrent AV dissociation and no visual His bundle potential, confirming the diagnosis of ventricular tachycardia (VT). Figure 1 illustrates 12-lead electrocardiograms recorded during overdrive pacing from the right ventricular apex (RVA) and right atrial septum during VT. The electroanatomical activation map revealed a distinctive focal breakout pattern with fractionated potentials originating from the para-Hisian region. In the noncoronary cusp (NCC), corresponding to the opposite side of the para-Hisian region, prolonged and fractionated ventricular potentials preceding QRS onset by 56 ms were recorded (Figure 2A). Figure 2B shows the intracardiac electrogram recorded during ventricular overdrive pacing from the NCC during VT. Based on these observations, what is the mechanisms underlying the tachycardia?