Background: As pediatric implantable cardioverter defibrillator (ICD) utilization increases, hospital admission rates will increase. Data regarding hospitalizations among pediatric patients with ICDs is lacking. In addition, hospital mortality rates are unknown. This study aimed to evaluate 1) trends in hospitalization rates of admissions over 20 years, 2) hospital mortality, and 3) factors associated with hospital mortality among pediatric admissions with ICDs. Methods: The Kids’ Inpatient Database (2000-2016) was used to identify all hospitalizations with an existing ICD 20 years of age. ICD9/10 codes were used to stratify admissions by underlying diagnostic category as: 1) congenital heart disease (CHD), 2) primary arrhythmia, 3) primary cardiomyopathy, or 4) other. Trends were analyzed using linear regression. Hospital and patient characteristics among hospital deaths were compared to those surviving to discharge using mixed multivariable logistic regression, accounting for hospital clustering. Results: Of 42,570,716 hospitalizations, 4165 were admitted <21 years with an ICD. ICD admissions increased four-fold (p = 0.002) between 2000-2016. Hospital death occurred in 54 (1.3%). In multivariable analysis, cardiomyopathy (OR 3.5, 95%CI 1.1–11.2, p=0.04) and CHD (OR 4.8, 95%CI 1.5–15.6, p=0.01) were significantly associated with mortality. In further exploratory multivariable analysis incorporating a coexisting diagnosis of heart failure, only the presence of heart failure remained associated with mortality (OR 8.6, 95%CI 3.7-20.0, p<0.0001). Conclusions: Pediatric ICD hospitalization are increasing over time and hospital mortality is low (1.3%). Hospital mortality is associated with cardiomyopathy or CHD; however, the underlying driver for in-hospital death may be heart failure.

A left bundle branch block morphology tachycardia with fragmented potentials at the His bundle area Masahiro Toba, MDa, Toshihiro Nasu, CEb, Nobuyoshi Nekomiya, CEb, Ryo Itasaka, CEb, Takao Makino, MDa, Hisashi Yokoshiki, MD, PhDaaDepartment of Cardiovascular Medicine, Sapporo City General Hospital, Sapporo, JapanbDivision of Medical Engineering Center, Sapporo City General Hospital, Sapporo, JapanAddress for correspondence :Hisashi Yokoshiki MD, PhDE-mail:[email protected] of Cardiovascular Medicine Sapporo City General Hospital, Kita-11, Nishi-13, Chuo-ku, Sapporo 060-8604, Japan.Phone: 81-11-726-2211Fax: 81-11-726-7912Key words : longitudinal dissociated his bundle, left bundle branch block morphology tachycardia, fragmented potentials, radiofrequency ablation

Background: Cryoballoon (CB) based pulmonary vein isolation (PVI) has proven to be as effective as radiofrequency (RF) based ablation. Different ablation protocols took the individual time-to-isolation (TTI) into account aiming at shorter but equally or even more effective freeze-cycles. The current study sought to assess the impact of the TTI on PVI durability in patients undergoing a repeat procedure for recurrence of atrial tachyarrhythmia (ATA). Methods and Results: In 205 patients with ATA recurrence after previous CB-based PVI a total of 806 PVs were identified. One hundred-twenty-six out of 806 PVs (16%) were previously treated with a TTI guided ablation (protocol #1; TTI+120 sec.), in 92/806 (11%) PVs TTI was only monitored (m) but fixed freeze-cycles were applied (protocol #2; mTTI) and in 588/806 (73%) a fixed freeze-cycle was applied without TTI-monitoring. There was no difference in the PV-reconduction rate between the groups (P=0.23). The right inferior pulmonary vein (RIPV) showed overall significantly higher reconduction rates compared to the other PVs (RIPV – left inferior PV (LIPV) p<0.003, -left superior PV (LSPV) p<0.001, - right superior PV RSPV p<0.013). In 21 patients (10%) only for the RIPV reconduction was assessed. Conclusions: TTI based CB ablation did not show significant differences regarding PV-reconduction rates compared to the other protocols.

Toward Better Risk Stratification of Asymptomatic Brugada Syndrome Patients? Najla Beydoun MD1 , Charbel Gharios MD2 , Marwan M. Refaat MD3 1 Department of Anesthesiology and Perioperative Medicine, Tufts Medical Center, Boston, MA2 Cardiovascular Imaging Research Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA3 Department of Internal Medicine, Division of Cardiology, and Department of Biochemistry and Molecular Genetics, American University of Beirut Faculty of Medicine and Medical Center, Beirut, LebanonShort Title: Risk Stratification in Asymptomatic BrSWord Counts: 602

Is Multipoint Pacing Superior to Optimized Single-Point Pacing?Rodolfo San Antonio1, MD; Jose María Tolosana2, MD, PhD; Lluís Mont2, MD, PhD.1Heart Institute, Teknon Medical Center, Barcelona, Spain; University of Barcelona, Spain2Institut Clínic Cardio-Vascular, Hospital Clínic, University of Barcelona, Spain; Institut d’Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.Word count: 434

Background: Simultaneous atrial fibrillation (AF) catheter ablation and left atrial appendage closure (LAAC) is sometimes recommended for both rhythm control and stroke prevention. However, the advantages of intracardiac echocardiography (ICE) guidance for this combined procedure have been scarcely reported. To evaluate the clinical outcomes and safety of ICE guided LAAC within a zero-fluoroscopy catheter ablation procedure. Methods and Results:From April 2019 to April 2020, 56 patients with symptomatic AF underwent concomitant catheter ablation and LAAC. ICE with a multi-angled imaging protocol mimicking the TEE echo windows was used to guide LAAC. Successful radiofrequency catheter ablation and LAAC was achieved in all patients. Procedure-related adverse event rate was 3.6%. During the 12-month follow-up, 77.8% of patients became free of arrhythmia recurrences and oral anticoagulants were discontinued in 96.4% of patients. No ischemic stroke occurred despite two cases of device-related thrombosis versus an expected stroke rate of 4.8% based on the CHA2DS2-VASc score. The overall major bleeding events rate was 1.8%, which represented a relative reduction of 68% versus an expected bleeding rate of 5.7% based on the HAS-BLED score of the patient cohort. The incidence of iatrogenic atrial septal defect secondary to a single transseptal access dropped from 57.9% at 2 months to 4.2% at 12 months TEE follow-up. Conclusion:The combination of catheter ablation and LAAC under ICE guidance was safe and effective in AF patients with high stroke risk. ICE with our novel protocol was technically feasible for comprehensive and systematic assessment of device implantation.

Background: Local impedance (LI) can indirectly measure catheter contact and tissue temperature during radiofrequency catheter ablation (RFCA). However, data on the effects of catheter contact angle on LI parameters are scarce. This study aimed to evaluate the influence of catheter contact angle on LI changes and lesion size with 2 different LI-sensing catheters in a porcine experimental study. Methods: Lesions were created by the INTELLANAV MiFi™ OI (MiFi) and the INTELLANAV STABLEPOINT™ (STABLEPOINT). RFCA was performed with 30 watts and a duration of 30 seconds. The CF (0, 5, 10, 20, and 30 g) and catheter contact angle (30°, 45°, and 90°) were changed in each set (n=8 each). The LI rise, LI drop, and lesion size were evaluated. Results: The LI rise increased as CF increased. There was no angular dependence with the LI rise under all CFs in the MiFi. On the other hand, the LI rise at 90° was lower than at 30° under 5 and 10 g of CF in STABLEPOINT. The LI drop increased as CF increased. Regarding the difference in catheter contact angles, the LI drop at 90° was lower than that at 30° for both catheters. The maximum lesion widths and surface widths were smaller at 90° than at 30°, whereas there were no differences in lesion depths. Conclusion: The LI drop and lesion widths at 90° were significantly smaller than those at 30°, although the lesion depths were not different among the 3 angles for the MiFi and STABLEPOINT.

Background: There exists variability in the administration of inpatient sotalol therapy for symptomatic atrial fibrillation(AF). The impact of this variability on patient in-hospital and 30-day post-hospitalization costs and outcomes is not known. Also, the cost impact of intravenous sotalol, which can accelerate drug loading to therapeutic levels, is unknown. Methods: 133 AF patients admitted for sotalol initiation at an Intermountain Healthcare Hospital from January 2017-December 2018 were included. Patient and dosing characteristics were described descriptively, and the impact of dosing schedule was correlated with daily hospital costs/clinical outcomes during the index hospitalization and for 30 days. The CMS reimbursement for 3-day sotalol initiation is $9,263.51. Projections of cost savings were made considering a 1-day load using intravenous sotalol that costs $2,500.00 to administer. Results: The average age was 70.3±12.3 years, 60.2% were male with comorbidities of: hypertension(83%), diabetes(36%), and coronary artery disease(53%). Mean ejection fraction was 59.9±7.8% and median QTc was 453.7±37.6 ms before sotalol. No ventricular arrhythmias developed, but bradycardia(<60 bpm) was observed in 37.6% of patients. The average length of stay was 3.9±4.6(median: 2.2) days. Post-discharge outcomes and rehospitalization rates stratified by length of stay were similar. The cost per day was estimated at $2,931.55 (1:$2,931.55, 2:$5,863.10, 3:$8,794.65, 4:$11,726.20). Conclusions: Inpatient sotalol dosing is markedly variable and results in the potential of both cost gain and loss to a hospital. In consideration of estimated costs, there is the potential for $871.55 cost savings compared to a 2-day oral load and $3,803.10 compared to a 3-day oral load.

Background: Increasing interest in physiological pacing has been countered with challenges such as accurate lead deployment and increasing pacing thresholds with His-bundle pacing (HBP). More recently, left bundle branch area pacing (LBBAP) has emerged as an alternative approach to physiologic pacing. Objective: To compare procedural outcomes and pacing parameters at follow-up during initial adoption of HBP and LBBAP at a single center. Methods: Retrospective review, from September 2016 to January 2020, identified the first 50 patients each who underwent successful HBP or LBBAP. Pacing parameters were then assessed at first follow-up after implantation and after approximately one year, evaluating for acceptable pacing parameters defined as sensing R-wave amplitude >5 mV, threshold <2.5 V @ 0.5 ms and impedance between 400 and 1200 Ohms. Results: The HBP group was younger with lower ejection fraction compared to LBBP (73.2±15.3 vs 78.2±9.2 years, p=0.047; 51.0±15.9% vs 57.0±13.1%, p = 0.044). Post-procedural QRS widths were similarly narrow (119.8±21.2 vs. 116.7±15.2ms; p = 0.443) in both groups. Significantly fewer patients with HBP met the outcome for acceptable pacing parameters at initial follow-up (56.0% vs 96.4%, p = 0.001) and most recent follow-up (60.7% vs 94.9%, p = <0.001; at 399±259 vs. 228±124 days, p = <0.001). More HBP patients required lead revision due to early battery depletion (0 vs 13.3%, at an average of 664 days). Conclusion: During initial adoption, as compared with LBBAP, HBP is associated with a significantly higher frequency of unacceptable pacing parameters, energy consumption, and lead revisions.

Introduction: Standard two-dimensional (2D), phased-array intracardiac echocardiography (ICE) is routinely used to guide interventional electrophysiology (EP) procedures. A novel four-dimensional (4D) ICE catheter (VeriSight Pro®, Philips, Andover, MA) can obtain 2D and three-dimensional (3D) volumetric images and cine-videos in real time (4D). The purpose of this study was to determine the early feasibility and safety of this 4D ICE catheter during EP procedures. Methods: The 4D ICE catheter was placed from the femoral vein in ten patients into various cardiac chambers to guide EP procedures requiring transseptal catheterization, including ablation for atrial fibrillation and left atrial appendage closure. 2D- and 3D- ICE images were acquired in real time by the electrophysiologist. A dedicated imaging expert performed digital steering to optimize and post-process 4D images. Results: Eight patients underwent pulmonary vein isolation (cryoballoon in 7 patients, pulsed field ablation in 1, additional radiofrequency left atrial ablation in 1). Two patients underwent left atrial appendage closure. High quality images of cardiac structures, transseptal catheterization equipment, guide sheaths, ablation tools, and closure devices were acquired with the ICE catheter tip positioned in the right atrium, left atrium, pulmonary vein, coronary sinus, right ventricle, and pulmonary artery. There were no complications. Conclusion: This is the first-in-human experience of a novel deflectable 4D ICE catheter used to guide EP procedures. 4D ICE imaging in safe and allows for acquisition of high-quality 2D and 3D images in real-time. Further use of 4D ICE will be needed to determine its added value for each EP procedure type.

Changing landscape of complex lead extractions: need for patient tailored use of armamentarium for very old leads Arif Elvan, MD, PhD, FESC, FEHRAIsala Heart Centre, Diagram Research, Zwolle, The NetherlandsFunding: NoneConflict of interest: NoneThe numbers of implanted cardiovascular implantable electronic devices (CIED) and leads increased tremendously in the past decades due to an expansion of indications and progressive ageing of the population. The increased demand for complex transvenous lead extractions (TLE) is mainly related to a higher relative incidence of CIED infections, malfunction of leads and the increased need for upgrading or revision of devices. Moreover, the landscape of lead extraction is changing in time with a relative increase in the proportion of old leads with a dwell time of ≥10 years (1, 2). The growing impact of these complex TLEs on the utilization of the health care system has driven dedicated invasive cardiac electrophysiologists and engineers to improve strategies and tools to enable operators to perform lead extractions in a safe, effective and patient-centered way, minimizing risks of morbidity and mortality. We all know that chronically implanted leads may develop extensive fibrous or calcified adhesions around the surrounding structures and require more complex extraction techniques. Of note, the ageing of leads is associated with decreased procedural and clinical success rates and increased risk of lead extraction related complications (1, 2, 3). Currently, the techniques and armamentarium used in the extraction of leads include traction, counter traction, locking stylets, telescoping sheaths, and powered rotational mechanical and laser sheaths.In this issue of the Journal of Cardiovascular Electrophysiology, Issa (4) investigated success and complication rates of complex TLE of very old leads, defined as leads with a dwelling time of ≥20 years compared with younger leads. The indications for TLE were mainly related to pocket (58.9%) and systemic infections (33.9%), and in a minority of patients TLE was performed for other non-infectious indications. Although clinical success was very high in the current study (97.1%), this high clinical success implicates that small residual parts were regarded as a satisfactory result, while non-extracted remnants can be of clinical importance, especially in patients with lead endocarditis. Therefore, the complete procedural success constitutes an important metric rather than clinical success, particularly in patients with infectious TLE indications, in whom extraction of the whole system without any remnants should be the ultimate procedural endpoint.Furthermore, in the study by Issa (4), patients were treated by a single experienced lead extraction specialist in a high-volume center. The results of this study cannot be extrapolated to less experienced operators or low volume centers. This study underlines the necessity of concentrating lead extractions to high-volume centers to provide the best care for these patients. Some single center series reported very low complication rates, which does not reflect potential complications that might be encountered during a complex lead extraction procedure, especially when performing extraction of very old leads with a dwelling time of ≥20 years. It seems reasonable to advocate that all lead extractions should be reserved to experienced centers with a thoracic surgeon standby during complex lead extraction procedures. It is, to my personal opinion, important to emphasize this issue instead of giving space for low volume centers to perform some of the expected “easy” lead extractions.Moreover, in the study by Issa (4), the laser sheath was the primary extraction tool used in the majority of the ≥20 years old leads and mechanical sheaths or femoral snares were only used after failure of laser sheaths. Complete procedural success was lower in the group of patients with very old leads compared with leads with a dwelling time of less than 20 years (90.7% versus 98.5%). However, angiography of the subclavian vein was not a standard routine procedure in all patients. It seems reasonable to incorporate venous angiography as a standard procedure in the workup for TLE (5). Of note, the complexity of the TLE in the group with leads less than 20 years old was very heterogeneous. It is remarkable that 55% of the leads required complex extraction techniques, whereas 45% of these leads could be extracted with manual traction only in this group of patients with less than 20 years old leads, highlighting the nonbinary nature of the extent of adhesions of aging leads to surrounding structures. Despite advances in lead extraction techniques, extraction of older leads in a safe and effective way remains challenging. Issa (4) demonstrated that complex TLE can be performed successfully and safely by a skilled and experienced operator in a specialized center. The rate of major complications was 5.6% including 1 death. These results are in line with previous publications (5, 6, 7).This latter study (4) underlines the importance of the use of combination of multiple extraction tools in enhancing procedural success rates. Especially in leads with a dwelling time of ≥20 years, there is an increased risk of extraction failure or incomplete success. Issa (4) primarily used laser sheaths while others used the powered mechanical sheath as the primary extraction tool. Several reports describing the results of case series were published on the success and complication rates of lead extractions with the use of mechanical sheaths (5, 6. 7). These studies described the results of case series. Moreover, Migliore et al (7) reported that complex lead extractions using the Evolution RL bidirectional rotational mechanical sheaths and ancillary tools in a systematic stepwise approach were effective and safe.The use of dedicated extraction tools and techniques yielded reported major adverse event rates of 2-3% with a mortality of 1% in previous studies (3, 5, 6, 7). In some previous reports, only powered mechanical sheaths were used with comparable results (5, 6, 7). The currently available armamentarium for complex lead extractions including laser sheaths, powered mechanical rotational sheaths and femoral snares enables operators to tailor the procedure in order to enhance procedural and clinical success rates. However, there is a lack of direct comparative data regarding risks and benefits of laser sheath compared with powered mechanical sheaths and femoral snares.Issa (4) performed analyses of retrospective data which should be regarded as exploratory and hypothesis generating. Nevertheless, this study provides data and conveys messages that are important to the clinical practice. The main finding is that transvenous extraction of leads with a dwelling time ≥20 years is associated with a considerable risk of major complications, even in the hands of an experienced operator and in the setting of a high-volume center. This study highlights the need for concentration of complex lead extractions to a selected number of highly specialized centers.Although, direct comparison of the available strategies and techniques has not been performed yet, these studies need to be performed in the near future. Clinicians need guidance based on firm evidence regarding comparative efficacy or safety of bidirectional powered mechanical sheaths and laser sheaths and femoral snares.There are no randomized trials comparing different extraction strategies. The current recommendations are based on outcome data derived from various case series.Therefore, international collaboration, merging of databases and ultimately randomized trials are crucial to gain more insight and to better delineate the incremental values of the available lead extraction tools and techniques.The innovations in the field of complex TLE techniques and tools will continue. In the meantime, the extraction of chronically implanted leads remains a complex procedure associated with major complications including mortality, mandating concentration to specialized centers and standardized metrics for monitoring procedural and clinical outcomes.

Letter to the editor

A document by Victor García-Hernando. Click on the document to view its contents.

Introduction: Prior to ablation, predicting the site of origin (SOO) of outflow tract ventricular arrhythmia (OTVA), can inform patient consent and facilitate appropriate procedural planning. We set out to determine if OTVA variability can accurately predict SOO. Methods: Consecutive patients with a clear SOO identified at OTVA ablation had their prior 24-hour ambulatory ECGs retrospectively analysed (derivation cohort). Percentage ventricular ectopic (VE) burden, hourly VE values, episodes of trigeminy/bigeminy, and the variability in these parameters were evaluated for their ability to distinguish right from left sided SOO. Effective parameters were then prospectively tested on a validation cohort of consecutive patients undergoing their first OTVA ablation. Results: High VE variability (coefficient of variation ≥ 0.7) and the presence of any hour with < 50 VE, were found to accurately predict RVOT SOO in a derivation cohort of 40 patients. In a validation cohort of 29 patients, the correct SOO was prospectively identified in 23/29 patients (79.3%) using CoV, and 26/29 patients (89.7%) using VE < 50. Including current ECG algorithms, VE < 50 had the highest Youden Index (78), the highest positive predictive value (95.0%) and the highest negative predictive value (77.8%). Conclusion: VE variability and the presence of a single hour where VE < 50 can be used to accurately predict SOO in patients with OTVA. Accuracy of these parameters compares favourably to existing ECG algorithms.

Brugada syndrome masked by complete left bundle branch blockAbbas Hoteit MD, Marwan M. Refaat, MDDivision of Cardiology, Department of Internal Medicine, American University of Beirut Medical Center, Beirut, LebanonRunning Title: Brugada Syndrome masked by LBBBWords: 741 (excluding the title page and references)Keywords: Brugada syndrome, Left bundle branch block, Cardiovascular Diseases, Heart Diseases, Cardiac ArrhythmiasFunding: NoneDisclosures: NoneCorresponding Author:Marwan M. Refaat, MD, FACC, FAHA, FHRS, FASE, FESC, FACP, FAAMAAssociate Professor of MedicineDirector, Cardiovascular Fellowship ProgramDepartment of Internal Medicine, Cardiovascular Medicine/Cardiac ElectrophysiologyDepartment of Biochemistry and Molecular GeneticsAmerican University of Beirut Faculty of Medicine and Medical CenterPO Box 11-0236, Riad El-Solh 1107 2020- Beirut, LebanonUS Address: 3 Dag Hammarskjold Plaza, 8th Floor, New York, NY 10017, USAOffice: +961-1-350000/+961-1-374374 Extension 5353 or Extension 5366 (Direct)Brugada syndrome is a genetic disorder that affects the electrical activity of the heart. It is characterized by ST-segment elevations in the right precordial leads and right bundle branch morphology on ECG.1 These ECG changes are present in the absence of other causes of ST elevation or right bundle branch block morphology such as structural heart disease, ischemia, pacing or electrolyte disturbances.2 Clinical presentation varies between patients; it can range from asymptomatic changes seen on ECG to syncope, ventricular arrhythmias, and sudden cardiac death. 3So far, three types of ECG repolarization patterns have been identified (type 1, type 2, and type 3).4 Type 1 pattern is diagnostic of Brugada syndrome whereas types 2 and 3 are considered suggestive.5 According to the 2016 consensus conference of J-wave syndromes, the diagnosis of Brugada syndrome can only be made by finding a type 1 repolarization pattern. A type 1 pattern can either be spontaneous or unmasked by fever or medications. If it has been unmasked by either, then further evidence of patient clinical history, family history, or genetic testing should be present to fulfill a score of 3.5 or higher according to the Shanghai Scoring System.6 7 The Shanghai Scoring System does not include imaging; hence, even if changes in the right ventricle are found on cardiac MRI, they play no role in the diagnosis. 7In patients presenting with a non-type 1 pattern, a sodium channel blocker challenge is frequently used to unmask the type 1 pattern. Unmasking this pattern allows for diagnosis of Brugada syndrome which has a big impact on prognosis and management options. In some patients, an initial flecainide challenge test may be negative due to the variable sensitivity of this test. Some studies have shown that repeating the test may increase sensitivity, but, with increased risk of adverse drug effects. Prasad et al. showed that in patients with high clinical suspicion, family history of sudden cardiac death could serve as an indicator to repeat the flecainide test.5 8 9Several possible risk factors, that might predispose individuals to have a more severe presentation, have been identified. These include male gender, history of syncope, spontaneous type 1 pattern, family history of Brugada syndrome, and loss-of-function mutations in the SCN5A gene (which codes the alpha subunit of the cardiac sodium channel).10 Patients with SCN5A mutations tend to have earlier onset of symptoms, more noticeable electrophysiological defects (such as sick sinus syndrome and AV blocks), and increased risk of major arrhythmic events especially in Asian and Caucasian populations.11 High-risk patients are susceptible to sudden cardiac death; therefore, risk stratification helps in patient selection for Implantable Cardioverter Defibrillator placement.12 13In their article, Eduardo et al. presented the case of a 48-year-old lady who was initially diagnosed with Brugada syndrome after having a type 1 pattern on ECG. During follow-up, the patient’s ECG changed and showed a complete left bundle branch block instead of the typical type 1 pattern. Molecular studies showed the novel SCN5A p.1449Y>H variant and subsequent functional analysis showed a nonfunctional mutated membrane channel. SCN5A mutation can cause Brugada syndrome and conduction system abnormality as described in this lady. This variant generated minimal sodium currents. Such major decrease in current magnitude is associated with high penetrance as seen in the cases in this study. Although, during close follow-up, these patients did not have severe symptoms.14 What is most significant is that the authors presented a patient with Brugada syndrome who subsequently developed findings of complete left bundle branch block on ECG, making the diagnosis challenging due to masking of the type 1 pattern. This opens further discussion about diagnosis of the syndrome and potential maneuvers or procedures that would help unmask type 1 pattern under heart block. Since diagnosis can only be made by witnessing this pattern, this presents us a possibility where a diagnosis would be missed in such patients. SCN5A is the most common gene associated with this syndrome, accounting for around 20%. However, patient presentation varies widely with different mutations affecting channel function differently. In this case, the p.1449Y>H variant showed high penetrance and channel dysfunction despite relatively non-severe symptoms in patients affected. However, further observation is warranted to assess progression of the disease and the incidence of major arrhythmogenic events with aging and subsequent fibrosis. Further research is required to investigate the role of genetic studies in risk stratification and projecting patient clinical course depending on the presence of specific gene mutations/variants.References:Refaat MM, Hotait M, Scheinman MM. Brugada Syndrome. Card Electrophysiol Clin Mar 2016; 8(1): 239-45.Refaat M, Mansour M, Singh JP, Ruskin JN, Heist EK. Electrocardiographic Characteristics in Right Ventricular Versus Biventricular Pacing in Patients With Paced Right Bundle Branch Block QRS Pattern. J Electrocardiol Mar-Apr 2011; 44 (2): 289-95.Tse G, Liu T, Li KH, et al. Electrophysiological mechanisms of Brugada syndrome: insights from pre-clinical and clinical studies. Front Physiol 2016; 7: 467.Wilde, A. a. M.; Antzelevitch, C.; Borggrefe, M.; Brugada, J.; Brugada, R.; Brugada, P.; Corrado, D.; Hauer, R. N. W.; Kass, R. S.; Nademanee, K.; Priori, S. G. (November 2002). ”Proposed diagnostic criteria for the Brugada syndrome”. European Heart Journal . 23  (21): 1648–1654.Prasad S, Namboodiri N, Thajudheen A, Singh G, Prabhu MA, Abhilash SP, Mohanan Nair KK, Rashid A, Ajit Kumar VK, Tharakan JA. Flecainide challenge test: Predictors of unmasking of type 1 Brugada ECG pattern among those with non-type 1 Brugada ECG pattern. Indian Pacing Electrophysiol J. 2016 Mar-Apr;16(2):53-58. doi: 10.1016/j.ipej.2016.06.001. Epub 2016 Jun 20. PMID: 27676161; PMCID: PMC5031807.Antzelevitch C, Yan GX, Ackerman MJ, et al. J-wave syndromes expert consensus conference report: emerging concepts and gaps in knowledge.Heart Rhythm 2016;13:e295-324.Vutthikraivit W, Rattanawong P, Putthapiban P, Sukhumthammarat W, Vathesatogkit P, Ngarmukos T, Thakkinstian A. Worldwide Prevalence of Brugada Syndrome: A Systematic Review and Meta-Analysis. Acta Cardiol Sin. 2018 May;34(3):267-277. doi: 10.6515/ACS.201805_34(3).20180302B. Erratum in: Acta Cardiol Sin. 2019 Mar;35(2):192. PMID: 29844648; PMCID: PMC5968343.Gasparini M, Priori SG, Mantica M, Napolitano C, Galimberti P, Ceriotti C, Simonini S. Flecainide test in Brugada syndrome: a reproducible but risky tool. Pacing Clin Electrophysiol. 2003 Jan;26(1P2):338-41. doi: 10.1046/j.1460-9592.2003.00045.x. PMID: 12687841.Dubner S, Azocar D, Gallino S, Cerantonio AR, Muryan S, Medrano J, Bruno C. Single oral flecainide dose to unmask type 1 Brugada syndrome electrocardiographic pattern. Ann Noninvasive Electrocardiol. 2013 May;18(3):256-61. doi: 10.1111/anec.12052. PMID: 23714084; PMCID: PMC6932426.Bayoumy A, Gong MQ, Christien Li KH, Wong SH, Wu WK, Li GP, Bazoukis G, Letsas KP, Wong WT, Xia YL, Liu T, Tse G; International Health Informatics Study (IHIS) Network. Spontaneous type 1 pattern, ventricular arrhythmias and sudden cardiac death in Brugada Syndrome: an updated systematic review and meta-analysis. J Geriatr Cardiol. 2017 Oct;14(10):639-643. doi: 10.11909/j.issn.1671-5411.2017.10.010. PMID: 29238365; PMCID: PMC5721199.Chen C, Tan Z, Zhu W, Fu L, Kong Q, Xiong Q, Yu J, Hong K. Brugada syndrome with SCN5A mutations exhibits more pronounced electrophysiological defects and more severe prognosis: A meta-analysis. Clin Genet. 2020 Jan;97(1):198-208. doi: 10.1111/cge.13552. Epub 2019 May 6. PMID: 30963536.Probst, V., Veltmann, C., Eckardt, L., Meregalli, P. G., Gaita, F., Tan, H. L., Wilde, A. A. (2010). Long‐term prognosis of patients diagnosed with Brugada syndrome: Results from the FINGER Brugada Syndrome Registry. Circulation , 121 (5), 635–643. https://doi.org/10.1161/circulationaha.109.887026.Rattanawong P, Chenbhanich J, Mekraksakit P, Vutthikraivit W, Chongsathidkiet P, Limpruttidham N, Prasitlumkum N, Chung EH. SCN5A mutation status increases the risk of major arrhythmic events in Asian populations with Brugada syndrome: systematic review and meta-analysis. Ann Noninvasive Electrocardiol. 2019 Jan;24(1):e12589. doi: 10.1111/anec.12589. Epub 2018 Aug 20. PMID: 30126015; PMCID: PMC6931443.

Introduction: The Atricure EPi-Sense Device is used for the hybrid convergent procedure, an emerging treatment for persistent atrial fibrillation and long standing persistent atrial fibrillation. However, data on the AE related to the EPi-Sense device are scarce. Methods: Keyword “EPI-SENSE” was searched on the MAUDE database. There were 80 device reports from 2016-2020. After excluding reports when the device was not returned for evaluation, 79 device reports were included for final analysis. Results: The adverse events were broadly classified into 11 categories. The most common complications were pericardial effusion (25.3%), stroke (17.7%) and atrio-esophageal fistula (AEF) (8.9%). Death was reported in 15 (19%) cases, 3 of which were due to pulmonary embolism, 6 due to AEF, 3 due to unknown cause, 1 due to sepsis, 2 due to events related to acute renal failure (ARF). Discussion: Pericardial effusion is a common AE reported in patients with convergence procedure and is well documented in the CONVERGE trial. Convergent procedure is unique in that the epicardial ablations are performed on the posterior wall with the radiofrequency probe directed towards the heart and away from the esophagus which in theory should reduce esophageal injuries. Despite that, a high number of AEF were noticed. Lastly, there were also some reports of saline perfusion malfunction which can lead to injuries due to overheating. Conclusion: This analysis of the AE related to the EPi-Sense device highlights several major adverse events that are previously unreported.

Application of electrocautery to a metal guidewire can be used to perform transseptal puncture (TSP). Dedicated radiofrequency guidewires (RF) may represent a better alternative. This study compares safety and effectiveness of electrified guidewires to a dedicated RF wire. TSP was performed on porcine hearts using an electrified 0.014” or 0.032” guidewire under various power settings compared to TSP using a dedicated RF wire with 5W power. The primary endpoint was the number of attempts required to achieve TSP. Secondary endpoints included the rate of TSP failure, TSP consistency, effect of the distance between tip of the guidewire and the tip of the dilator, and effect of RF power output level. Qualitative secondary endpoints included tissue puncture defect appearance, thermal damage to the TSP guidewire or dilator, and tissue temperature using thermal imaging. The RF wire required 1.10 ± 0.47 attempts to cross the septum. The 0.014” electrified guidewire required 2.17 ± 2.36 attempts (2.0x higher than the RF wire; p<0.01), and the 0.032” electrified guidewire required 3.90 ± 2.93 attempts (3.5x higher than the RF wire; p<0.01). Electrified guidewires had a higher rate of TSP failure, larger defects, more tissue charring, higher temperatures, and greater tissue heating. Fewer RF applications were required to achieve TSP using a dedicated RF wire compared to an electrified guidewire. Smaller defects and lower tissue temperatures were also observed using the RF wire. Electrified guidewires required greater energy delivery and were associated with equipment damage and tissue charring.

Background The single procedure success rates of durable pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) varies between 80 and 90 %. This prospective, randomized study investigated the efficacy of Cryoballoon PVI (CBA) versus pulmonary vein isolation with RF-energy following the CLOSE protocol in terms of single-procedure arrhythmia-free outcome and safety. Methods and results A total number of 150 patients undergoing de-novo catheter ablation for paroxysmal AF were randomized to two different treatment arms in a 1:1 fashion. In group-A patients, PVI was performed with the Cryoballoon (Articfront Balloon, Medtronic Inc). The ablation procedure in group B was performed with RF-energy (CARTO 3, Biosense Webster Thermocool STSF), following the CLOSE protocol. During a mean follow-up of 12  4.5 months after a single procedure, 64 (85.33 %) patients of group A were free of arrhythmia recurrence versus 65 (86.67 %) patients in group B (p=ns). A total of 14 patients (group A: 7 (9.33 %) group B: 7 (9.33 %); p=ns) underwent a redo-procedure. No significant difference between both groups was observed in terms of PV recovery (group A: 4 (5.33 %) vs. group B: 3 (4 %); p=ns). Patients of group A showed significantly more AF recurrence during the blanking period of three months (group A: 14 (18.67 %) versus group B: 6 (8 %); p<0.05. Conclusions Cryoballoon PVI and PVI using ablation index following the CLOSE protocol are equally efficient in achieving durable PV-isolation. Cryoballoon ablation leads to significantly more AF recurrence during the blanking period.