Device Interrogation Research Articles

Superior vena cava isolation with pulsed field ablation in the presence of defibrillator leads.

Two patients with a history of dilated cardiomyopathy, dual chamber defibrillator implantation, and worsening heart failure because of persistent atrial fibrillation (AF) underwent catheter ablation of AF. Pulsed field ablation (PFA) was selected for the index procedure in these decompensated heart failure patients with enlarged atria.1 The 12-Fr over-the-wire pentaspline PFA catheter (Farawave) was advanced through a 13-Fr steerable sheath (Faradrive) to the ostium of each PV, and a total of eight PFA lesions were applied per vein. Phrenic nerve function was evaluated by direct phrenic capture and by observing diaphragmatic motion during inspiration. For posterior wall ablation, the catheter was placed into a flower configuration and positioned along the posterior left atrium to deliver overlapping sets of pulses at each location. As per institution protocol, superior vena cava (SVC), as a potential nonpulmonary trigger for AF, is isolated when active despite a risk of sinus node injury.2 Basket configuration (Figure 1) and two sets of two lesions at the trunk of the vessel (with rotation between each pair) were used for SVC isolation in the presence of atrial and defibrillator leads, without any impact on device and leads measurements or sinus node function (Figure 2). We observed incidence of phrenic capture during PFA, and no evidence of phrenic injury was detected after the procedure. Both patients were in AF and cardioverted into sinus rhythm post-SVC isolation. They remained at sinus rhythm at regular 3-month follow-up while device interrogation revealed intact sinus node function. Only 4.2% of operators in the MANIFEST-PF multinational survey (including 1758 consecutive unselected AF patients) performed SVC isolation by mean of PFA occasionally.3 This is the first report of off-label pulsed field ablation-mediated SVC isolation without device or lead malfunction. Human studies evaluating cardiac implantable electrical devices during ablation procedure remain limited. A recent study by a high-volume center indicated that PFA is a safe and feasible method in patients with devices in the terms of alterations in pacing, sensing, or impedance parameters, inappropriate anti-tachycardia pacing, and ICD shock and leads dislodgment.4 Indeed, our pilot procedures with PFA applications in the SVC of AF patients with implanted devices confirmed the previous results without apparent additional risk because of energy application adjacent to the electrodes. None declared. None. The authors declare no conflict of interests for this article. Approval of the research protocol: N/A. Informed Consent: Ν/Α. Registry and the Registration No. of the study/trial: N/A. Animal Studies: N/A. Data are available in the article.

Evolution and triggers of defibrillator shocks in patients with arrhythmogenic right ventricular cardiomyopathy

IntroductionImplantable cardioverter-defibrillators (ICDs) can prevent sudden cardiac death due to ventricular arrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). The aim of our study was to assess the cumulative...

Machine Learning-Based Phenomapping in Patients with Heart Failure and Secondary Prevention Implantable Cardioverter-Defibrillator Implantation: A Proof-of-Concept Study.

Previous studies have failed to implement risk stratification in patients with heart failure (HF) who are eligible for secondary implantable cardioverter-defibrillator (ICD) implantation. We aimed to evaluate whether machine learning-based phenomapping using routinely available clinical data can identify subgroups that differ in characteristics and prognoses. A total of 389 patients with chronic HF implanted with an ICD were included, and forty-four baseline variables were collected. Phenomapping was performed using hierarchical k-means clustering based on factor analysis of mixed data (FAMD). The utility of phenomapping was validated by comparing the baseline features and outcomes of the first appropriate shock and all-cause death among the phenogroups. During a median follow-up of 2.7 years for device interrogation and 5.1 years for survival status, 142 (36.5%) first appropriate shocks and 113 (29.0%) all-cause deaths occurred. The first 12 principal components extracted using the FAMD, explaining 60.5% of the total variability, were left for phenomapping. Three mutually exclusive phenogroups were identified. Phenogroup 1 comprised the oldest patients with ischemic cardiomyopathy; had the highest proportion of diabetes mellitus, hypertension, and hyperlipidemia; and had the most favorable cardiac structure and function among the phenogroups. Phenogroup 2 included the youngest patients, mostly those with non-ischemic cardiomyopathy, who had intermediate heart dimensions and function, and the fewest comorbidities. Phenogroup 3 had the worst HF progression. Kaplan-Meier curves revealed significant differences in the first appropriate shock (p = 0.002) and all-cause death (p 0.001) across the phenogroups. After adjusting for medications in Cox regression, phenogroups 2 and 3 displayed a graded increase in appropriate shock risk (hazard ratio [HR] 1.54, 95% confidence interval [CI] 1.03-2.28, p = 0.033; HR 2.21, 95% CI 1.42-3.43, p 0.001, respectively; p for trend 0.001) compared to phenogroup 1. Regarding mortality risk, phenogroup 3 was associated with an increased risk (HR 2.25, 95% CI 1.45-3.49, p 0.001). In contrast, phenogroup 2 had a risk (p = 0.124) comparable with phenogroup 1. Machine-learning-based phenomapping can identify distinct phenotype subgroups in patients with clinically heterogeneous HF with secondary prophylactic ICD therapy. This novel strategy may aid personalized medicine for these patients.

Remote-control Interrogation, Testing, and Reprogramming of Cardiac Implantable Electronic Devices with Telehealth Protocol for the Management of Patients at Home: The DOMUM REMOTUS Study.

Remote control (RC) of cardiac implantable electronic devices (CIEDs) has been tested as safe and effective in the magnetic resonance imaging space. We sought to evaluate RC applications of patients at home. RC of cardiac devices in patients' homes is feasible, safe, and effective, with consistent patient satisfaction. Patients with CIEDs using the CareLink™ network (Medtronic, Minneapolis, MN, USA) participated in a pair of home RC sessions. A technician visited the patient's house and set up a telehealth tablet and a programmer, which included inputting a session key enabling programmer access via a third-party host. The investigator video-conferenced with the patient and remotely controlled the programmer for device testing and data assessment, using a cellular hotspot for Internet connection. Reprogramming was performed as necessary. In all cases, an RC session legend was programmed in the device information field as a control. The patients then completed an experience questionnaire. One hundred fifty patients (99 pacemakers and 51 implantable cardioverter-defibrillators) completed 2 RC sessions, for 300 RC sessions in total. There were no complications or communication interruptions once the system communication proved stable after the first minute. In 26 sessions, initial communication was interrupted upon device interrogation, requiring communication to be re-established (which sometimes necessitated switching to an alternative carrier). Clinically driven parameter reprogramming was performed in 58 RC sessions (39%). Programming of notations concerning RC sessions was performed in all 300 sessions. The average duration of the RC sessions was 11 min. Patients' satisfaction scored 4.5 out of 5 points. In conclusion, RC management of cardiac devices at patients' homes is safe, effective, convenient, and associated with high patient satisfaction. This technology may prove very useful in a changing health care delivery system, especially amid the coronavirus disease 2019 pandemic.

Assisted reality device to guide cardiac implantable device programming in distant rural areas.

Patients with cardiac implantable electronic devices (CIEDs) living in rural areas have difficulty obtaining follow-up visits for device interrogation and programming in specialized healthcare facilities. To describe the use of an assisted reality device designed to provide front-line workers with real-time online support from a remotely located specialist (Realwear HTM-1; Realwear) during CIED assistance in distant rural areas. This is a prospective study of patients requiring CIED interrogation using the Realwear HMT-1 in a remote rural population in Colombia between April 2021 and June 2022. CIED interrogation and device programming were performed by a general practitioner and guided by a cardiac electrophysiologist. Non-CIED-related medical interventions were allowed and analyzed. The primary objective was to determine the incidence of clinically significant CIED alerts. Secondary objectives were the changes medical interventions used to treat the events found in the device interrogations regarding non-CIED related conditions. A total of 205 CIED interrogations were performed on 139 patients (age 69 ± 14 years; 54% female). Clinically significant CIED alerts were reported in 42% of CIED interrogations, consisting of the detection of significant arrhythmias (35%), lead malfunction (3%), and device in elective replacement interval (3.9%). Oral anticoagulation was initiated in 8% of patients and general medical/cardiac interventions unrelated to the CIED were performed in 52% of CIED encounters. Remote assistance using a commercially available assisted reality device has the potential to provide specialized healthcare to patients in difficult-to-reach areas, overcoming current difficulties associated with RM, including the inability to change device programming. Additionally, these interactions provided care beyond CIED-related interventions, thus delivering significant social and clinical impact to remote rural populations.

Data-driven multi-joint waveguide bending sensor based on time series neural network.

Due to the bulky interrogation devices, traditional fiber optic sensing system is mainly connected by wire or equipped only for large facilities. However, the advancement in neural network algorithms and flexible materials has broadened its application scenarios to bionics. In this paper, a multi-joint waveguide bending sensor based on color dyed filters is designed to detect bending angles, directions and positions. The sensors are fabricated by casting method using soft silicone rubber. Besides, required optical properties of sensor materials are characterized to better understand principles of the sensor design. Time series neural networks are utilized to predict bending position and angle quantitatively. The results confirm that the waveguide sensor demodulated by the data-driven neural network algorithm performs well and can be used for engineering applications.

Management of hemodynamically stable wide QRS complex tachycardia in patients with implantable cardioverter defibrillators.

The preparation phase includes reversal of potential arrhythmia "triggers", mild patient sedation, and patient monitoring for therapy delivery. Based on resource availability and competences, the most adequate therapeutic approach is chosen. This choice depends on whether a device specialist is readily available or not. In the case of ES in a "high-risk" patient an accelerated patient management protocol is advocated, which considers urgent ventricular tachycardia transcatheter ablation with or without mechanical cardiocirculatory support. Therapeutic phase is based on the use of intravenous anti-arrhythmic drugs mostly indicated in this clinical context are presented. Device interrogation is very important in this phase when sustained monomorphic VT diagnosis is confirmed, then ICD ATP algorithms, based on underlying VT cycle length, are proposed. In high-risk patients with intractable ES, intensive patient management considers MCS and transcatheter ablation. The patient is hospitalized for further diagnostics and management aimed at preventing arrhythmia recurrences.

Open multi-organ communication device for easy interrogation of tissue slices.

Here, we have developed an open multi-organ communication device that facilitates cellular and molecular communication between ex vivo organ slices. Measuring communication between organs is vital for understanding the mechanisms of health regulation yet remains difficult with current technology. Communication between organs along the gut-brain-immune axis is a key regulator of gut homeostasis. As a novel application of the device, we have used tissue slices from the Peyer's patch (PP) and mesenteric lymph node (MLN) due to their importance in gut immunity; however, any organ slices could be used here. The device was designed and fabricated using a combination of 3D printed molds for polydimethylsiloxane (PDMS) soft lithography, PDMS membranes, and track-etch porous membranes. To validate cellular and protein transfer between organs on-chip, we used fluorescence microscopy to quantitate movement of fluorescent proteins and cells from the PP to the MLN, replicating the initial response to immune stimuli in the gut. IFN-γ secretion during perfusion from a naïve vs. inflamed PP to a healthy MLN was quantitated to demonstrate soluble signaling molecules are moving on-chip. Finally, transient catecholamine release was measured during perfusion from PP to MLN using fast-scan cyclic voltammetry at carbon-fiber microelectrodes to demonstrate a novel application of the device for real-time sensing during communication. Overall, we show an open-well multi-organ device capable of facilitating transfer of soluble factors and cells with the added benefit of being available for external analysis techniques like electrochemical sensing which will advance abilities to probe communication in real-time across multiple organs ex vivo.

918 EARLY RECOGNITION OF SUBCLINICAL ATRIAL FIBRILLATION IN PATIENTS IMPLANTED WITH DIFFERENT DEVICES

Abstract Background Atrial fibrillation (AF) is the supra-ventricular tachyarrhythmia mostly encountered in the clinical practice.While appearing silent or with a constellation of symptoms, it confers a 5-fold risk of stroke. Early detection is mandatory to establish the diagnosis and recommend anticoagulation. Besides the arrhythmia recognition through several tools, such as Holter ECG and loop recorders, it has been underlined that cardiac implantable electronic devices with an atrial lead can help in recognizing asymptomatic AF periods, also known as atrial high-rate episodes (AHREs). Materials and Methods 48 patients with AHRE detection at device telemetry checks were enrolled; implanted device were pacemakers (n=31, 64.8%); implantable cardioverter/defibrillators (ICD, n=8, 16.6%); cardiac resynchronization therapy devices with defibrillators (CRT-D, n=9, 18.5%). Male gender was predominant (40 vs. 8), age was > 65years, and mean CHA2DS2VASc was 4.2±2.8. Patients underwent ECG assessment in 6-month intervals (at baseline and during follow-up), MOntreal Cognitive Assessment test, and device interrogation for AHRE of duration >5 minutes and rate >175 beats per minute. Randomization to a direct oral anticoagulant (DOAC) or usual care (aspirin when needed or placebo) was provided in a blind fashion and maintained for the entire study observation until occurrence of overt AF, followed by exclusion from the study. Results We found that 13%-16% of patients with device-detected AHRE developed AF over a mean follow-up of 2.5 year (range 4.6±2.0). These cases were given oral anticoagulation since change of indication according to current guidelines. Most important comorbidities were coronary artery disease (n=18 patients, 36.73%); systemic hypertension (n=41, 83.67%); diabetes (n=13, 26.53%); dyslipidemia (n=23, 46.8%); heart failure (n=17, 35.4%). 30 patients were treated with beta-blockers(62.5%). 2 patients died for gastrointestinal bleeding. One patient was excluded for major bleeding after one month from the enrollment. Total AHREs duration was significantly lower in patients with pacemaker (14 hrs) compared to patients with CRT-D (17 hrs) and ICD (20 hrs, p<0.05). Conclusions The impact of AHREs was higher in patients affected by cardiac dysfunction and concomitant diseases; none of the patients enrolled in the study developed ischemic stroke; major bleedings were observed in both arms. Further studies are warranted for considering oral anticoagulation based on the sole device interrogation in the context of subclinical atrial fibrillation.

678 WIDE COMPLEX TACHYCARDIA IN A PATIENT TREATED WITH PERMANENT HIS BUNDLE PACING: A CASE REPORT

Abstract Introduction Differential diagnosis of wide complex tachycardias based only on ECG analysis remains a challenging exercise. But, when intracardiac tracings are available (i.e., pacemaker EGM), electrophysiologists may consider several tricks to make a correct diagnosis. Case Presentation A 73-years-old sporty male was admitted to our hospital for palpitations and dizziness. ECG monitoring revealed AF, typical atrial flutter and asystolic pauses following spontaneous cardioversion of atrial arrhythmias. We diagnosed sick sinus syndrome and implanted a dual-chamber pacemaker with an atrial lead in the right appendage and a stylet-directed active fixation lead in the His region, obtaining non-selective narrow paced QRS. The day after PM implantation, during a new episode of AF, two runs of regular wide-complex tachycardia (LBBB morphology, cycle length of 270 ms) occurred (Fig 1A, B). LBBB morphology, patient's history, and AF favored aberrancy, but couldn't exclude VT or preexcitation (by atrio-fascicular AP). Our diagnostic strategy consisted in adding atrial and His intracardiac electrograms registered by pacemaker to analysis of ECG traces. The device interrogation showed AV dissociation at the time of the wide complex tachyarrhythmia and a negative HV interval (Fig. 2A). These findings ruled out aberrant ventricular conduction and bundle branch reentrant tachycardia, because both these arrhythmias are characterized by HV ≥ HV in sinus rhythm. We performed incremental atrial pacing maneuver, during SR, obtaining decremental AH conduction with constant HV interval (60 ms), excluding atrio-fascicular, nodo-fascicular and nodo-ventricular AP. His bundle activity was identified just after the ventricular activation, producing a relatively short VH interval, suggesting the presence of a retrograde activation of the His bundle, therefore it was possible to hypothesize that the site of origin of the ventricular arrhythmia was within/or very close to RBB (Fig 2B, C). Just in few beats His bundle deflection was missing, probably because of recovery of functional LBBB (Fig 2D). Discussion Our final diagnosis was RBB VT. Patient was treated with Verapamil 80 mg t.i.d., with no further recurrence. This case highlights the diagnostic value of device interrogation in patients with permanent His bundle pacing, for the evaluation of wide complex tachycardias.

322 TRICUSPID VALVE REGURGITATION AFTER TRANSVENOUS LEAD EXTRACTION: WE NEED TO KNOW MORE

Abstract Since 2003 a 73-year-old man was submitted to a pacemaker implantation because of atrio-ventricular block. After fourteen years, upgrading to CRT-D was made due to recovery for acute heart failure in a dilated cardiomyopathy with severe left ventricular systolic dysfunction. In 2019 and 2020 he presented pocket erosion therefore underwent to a submuscular reimplantation. After one year, he came to Arrhythmology outpatient appointment with inflammatory signs of the CRT-D pocket. The patient was started on Meropenem and Vancomicin. Transthoracic (TTE) and transesophageal echocardiogram didn't reveal any vegetation on valvular apparatus or on leads. The patient was submitted to transvenous lead extraction (TLE) with bidirectional rotational mechanical sheats and a epicardial lead on postero-lateral left ventricular wall was implanted. The post-procedural TTE showed a moderate to severe organic tricuspid valve regurgitation with annular dilatation despite the patient was asymptomatic. There weren't flail leaflets or tricuspid valve damage. The reimplantation of right atrial and ventricular leads was hindered by complex venous anatomy documented by intraprocedural phlebography. After Heart Team discussion, we agreed to tricuspid valve repair with annuloplasty ring and other two epicardial leads - right atrial and ventricular - was implanted. We achieve a successful result without complications. The patients was discharged without symptoms; the device interrogation showed good assessment of lead impedances, sensing thresholds, and capture thresholds. Conclusion The mechanisms of tricuspid valve regurgitation following TLE are complex. There isn't a standardized best practice to approach this phenomenon. It's important after TLE to assess tricuspid valve structure and function with TTE in order to understand the incidence of underlying potential mechanism and how to prevent it. Complex venous anatomy could direct the choice toward epicardial leads implantation.

Remote interrogation and reprogramming of cardiac implantable electronic devices using a custom multivendor solution

Until recently, remote interrogation and reprogramming of therapeutic cardiac implantable electronic devices (CIEDs) have been virtually nonexistent owing to technical challenges and safety concerns. It could be extremely useful, in particular in case of emergencies, when patients live far from CIED professionals or during enforced physical distancing. We investigated the feasibility and safety of a custom solution for remote interrogation and reprogramming of CIEDs from various manufacturers in various clinically relevant situations. Our solution consists of remote controlling CIED programmers through screen capture and remote cursor control. In this multicenter feasibility study, the primary outcome was technical feasibility (% of success) and safety (absence of complication) of interrogation and reprogramming when indicated in clinically driven encounters. A total of 115 remote interrogations were performed in110 patients: within the hospital (n = 73), medium range (50-100 km; n = 22), and long range (>5000 km; n = 20). Implanted devices were pacemakers (n = 85) and implantable cardioverter-defibrillators (n = 25) from Abbott (N=13), Biotronik (n = 65), and MicroPort (n = 32). Patients were located in the outpatient clinic, cardiology department, radiology department (magnetic resonance imaging), operating room (per implantation), and intensive care unit. Teleworking was performed in 39 cases. Complete CIED interrogations succeeded in all patients with reprogramming in 56 of 115 sessions (49%). No clinical or technical complications occurred. The time lag for screen interaction was below 1 second. Remote interrogation and reprogramming of CIEDs are feasible and safe across disparate clinical contexts and distances. This strategy may enhance health care access and facilitate medical training, tele-expertise, and telework worldwide.

An unusual cause of pacemaker malfunction: A case report of an association of twiddler and reel syndrome

Lead dislodgement syndromes (Twiddler, Ratchet or Reel syndromes) are rare causes of cardiac stimulation device malfunction that can occur most commonly early after device implantation. Each one of them associated with a unique pattern of lead coiling and dysfunction. Our clinical case reports an unusual association and shed the light on the available diagnostic modalities. A 62-year-old woman who was referred to our hospital for a symptomatic high degree AV block, she underwent dual chamber pacemaker implantation. She experienced 3 weeks following implantation a rhythmic twitching of the right arm without syncope. The device interrogation revealed an increase in both leads pacing impedance and chest X-ray showed leads had pulled out of the heart and were tangling and wrapped repeatedly around the pulse generator. Revision procedure was performed to reposition the leads. Recognizing this complication early can prevent life threatening complication and is then of the utmost importance. Twiddler's syndrome is due to rotation of the device along its long axis. Reel syndrome is produced by device rotation along the transverse axis. In most cases, lead replacement or reposition is needed. Preventive measures such as patient education and use of a smaller pocket will reduce the risk of developing the syndrome. Our case highlights the available diagnostic modalities for early detection of twiddler's syndrome. The unique nature of this case increases the importance of considering device lead dislodgement as the cause for patients presenting with extra-cardiac symptoms.

Prevalence of atrial fibrillation and procedural outcome in patients undergoing catheter ablation for premature ventricular complexes.

Atrial fibrillation (AF) and premature ventricular complexes (PVC) are common arrhythmias. We aimed to investigate AF prevalence in patients with PVC and its impact on PVC ablation outcomes. Consecutive patients undergoing PVC ablation at a single institution between 2016 and 2019 were included and prospectively followed for 2 years. Patients with severe valvular heart disease, hyperthyroidism, malignancy, alcohol use disorder and advanced renal/hepatic diseases were excluded. Twelve-lead electrocardiograms were used to diagnose AF and assess PVC morphology. All PVCs were targeted for ablation using 4-mm irrigated-tip catheters at standardized radiofrequency power guided by 3-D mapping and intracardiac echocardiography. Patients were followed with remote monitoring, device interrogations and office visits every 6 months for 2 years. Detection of any PVCs in follow-up was considered as recurrence. A total of 394 patients underwent PVC ablation and 96 (24%) had concurrent AF. Patients with PVC and AF were significantly older (68.2 ± 10.8 vs. 58.3 ± 15.8 years, p < .001), had lower LV ejection fraction (43.3 ± 13.3% vs. 49.6 ± 12.4%, p < .001), higher CHA2 DS2 -VASc (2.8 ± 1.3 vs. 2.0 ± 1.3, p < .001) than those without. PVCs with ≥2 morphologies were detected in 60.4% and 13.7% patients with vs without AF (p < .001). At 2-year follow-up, PVC recurrence rate was significantly higher in patients with vs without AF (17.7% vs. 9.4%, p = .02). AF was documented in 1/4 of patients undergoing PVC ablation and was associated with lower procedural success at long-term follow-up. This was likely attributed to older age, worse LV function and higher prevalence of multiple PVC morphologies in patients with concurrent AF.

External cardioversion of atrial fibrillation and flutter in patients with cardiac implantable electrical devices.

Atrial fibrillation and flutter are often treated with external electrical cardioversion (ECV) in patients with potentially electrically sensitive cardiovascular implantable electronic devices (CIED). Long-term follow-up data on contemporary CIED undergoing ECV is sparse. The aim is to investigate shock-related complications and impact on CIEDs. All ECV procedures from 2010 to 2020 in patients with CIED performed at a tertiary university hospital were identified in the Danish National Patient Registry. Changes in device measurements after ECV were retrospectively studied and procedure-related complications were identified by review of medical records. We analyzed 763 ECV procedures in 372 patients, median device implant time 1.9years. The mean age of patients was 69.9±9.9years of which 73.4% were men. We identified two cases of device programming changes and four cases of premature battery depletion (≤3years after device implant). Minor changes in device measurements were found for impedances, sensing, and pacing thresholds. No patients died due to ECV-related device dysfunctions within the first 12 months after cardioversions. External cardioversion in patients with contemporary pacemakers and implantable cardioverter-defibrillators seems safe in the majority of patients. Clinically important changes in device function following cardioversion were rarely observed but may be critical for device function. In an observational study, causality between cardioversion and device dysfunction cannot be established. For patient safety, we suggest that routine device interrogation after cardioversion still should be part of standard care.

Abstract 14888: Arrhythmogenic Right Ventricular Cardiomyopathy-Brugada Syndrome Overlap: A Rare Clinical Entity

Introduction: Arrhythmogenic right ventricular cardiomyopathy (ARVC) and Brugada syndrome (BS) are inherited disorders that predispose individuals to arrhythmic sudden cardiac death. ARVC is a heart muscle disorder of intercellular junctions resulting from mutations of desmosomal (DS) genes, often leading to heart failure, and monomorphic ventricular tachycardia (VT). BS is a channelopathy due to sodium channel mutations, usually presenting as polymorphic VT without cardiomyopathy. Case presentation: A 35-year-old male with history of migraines presented with syncope resulting in a fall. No family history of arrhythmias or sudden cardiac death. Initial EKG showed wide complex monomorphic VT. Repeat EKG (figure 1), revealed coved ST-segment elevations in V1, V2 consistent with Brugada type 1 pattern. Emergent coronary angiography was unremarkable, and echocardiogram showed left ventricular ejection fraction of 55-60%, right ventricle (RV) outflow tract proximal diameter measured 3.5cm and normal RV function. An implantable cardioverter-defibrillator (ICD) was implanted for secondary prevention. Device interrogation on follow-up showed 11 shocks for recurrent episodes of monomorphic VT and patient was started on quinidine maintenance therapy. He remained symptom-free on subsequent visits. Genetic testing was positive for DSC2, DSP, and TMEM43 mutations associated with ARVC, but negative for genes associated with BS. Cardiac MRI results are pending. Discussion: Our patient has overlapping features of ARVC (genotype and monomorphic VT) and BS (EKG with coved ST elevations in V1, V2). Emerging evidence supports the theory that defects in DS proteins may affect the integrity of voltage-gated sodium channels in cardiac intercalated discs, leading to BS like phenotype. Conclusion: ARVC and BS could be related to the same disease spectrum, but further studies are required to understand pathophysiology, to guide treatment decisions.

Abstract 15433: Very Late Recurrence After Successful Ablation of Premature Ventricular Contractions in Patients Without Structural Heart Disease

Background: Earlier studies have shown the superiority of catheter ablation over pharmacological therapy in eliminating premature ventricular contractions (PVC) in patients without structural heart disease. We investigated very late recurrences after successful PVC ablation in this cohort. Methods: Consecutive patients undergoing clinically indicated radiofrequency ablation for symptomatic idiopathic PVCs, documented by standard ECG, were included in the analysis and prospectively followed up. Those with history of structural heart disease were excluded. For all patients, 12-lead ECGs were reviewed to assess PVC morphology. During the index procedure, all PVC morphologies were targeted for ablation. Standardized RF power settings (40-50 W) were used during the procedure. Ablation was performed using 4-mm irrigated tip catheter guided by 3-D mapping system and intra-cardiac echocardiography. Patients were followed up with remote monitoring as well as ICD interrogations and office visits every 6 months for 4 years. Long-term success was defined as absence of previously targeted PVCs or any new PVC morphology on 12-lead ECG or device interrogation during all follow-up visits. Results: In total, 638 patients were included (mean age 59.2±5.6 years, 69.75% male, LVEF 54±12%). At the index ablation, PVCs were detected to be localized in the right ventricular outflow tract in 268 (42%), left ventricular outflow tract in 299 (46.8%) and multiple sites of origin in 71 (11.2%) patients. Non-inducibility was achieved in all patients at the end of the index procedure. At 4 years, 585 (91.7%) patients remained arrhythmia-free. Remaining 53 patients (8.1%) experiencing recurrence underwent repeat procedure. Median time to recurrence was 29±6.2 months. At the redo, new PVC morphologies were detected and ablated in 46/53 (86.8%) patients. One year after the repeat ablation, 50/53 (94.3%) were arrhythmia-free. Conclusion: In this prospective single-center series, very late recurrence following index PVC ablation in patients with no structural heart disease was mostly associated with new PVC morphologies that were amenable to be successfully ablated at the repeat procedure.

Abstract 14437: Safety of Fluoroless Radiofrequency Ablation for Atrial Fibrillation in Patients With Pre-Existing Cardiac Implantable Electronic Device

Introduction: Radiofrequency catheter ablation (RFA) for atrial fibrillation (AF) is being increasingly performed without fluoroscopy. There is limited experience in flouroless RFA for AF in patients with pre-existing cardiac implantable electronic devices (CIED). Hypothesis: The safety of Fluoroless RFA for AF in patients with pre-existing CIED is uncertain. Methods: In this single-center study, we retrospectively evaluated patients undergoing fluoroless RFA for AF with pre-existing CIED in situ. A total of two hundred and sixty-four (264) consecutive fluoroless RFA procedures for AF from 6/1/2019 to 5/2/2022 were evaluated. All procedures were performed with intracardiac echocardiography (ICE) support. We assessed rates of CIED-related complications and changes in lead parameters over 30 days of follow-up. Pre and post-ablation device interrogations were reviewed for interval changes and compared for any change in the device or lead parameters. Patients were tracked for any subsequent device malfunction. Results: Among 264 fluoroless AF ablations patients, 25 (9.5%) had pre-existing CIED (13 dual-chamber pacemakers, 4 dual-chamber defibrillators, 4 single-chamber defibrillators/pacemakers, and 4 biventricular devices). Mean age was 71.2 ± 6.0 years with mean duration of indwelling CIED was 1821.1 ± 1586.8 days (see Table). Two (0.07%) patients had lead-related fibrin on ICE imaging. There was no significant difference in lead(s) threshold, impedance, or sensing post-procedure or at 30-days follow-up compared to pre-procedure (see Table). There were no intra- or post-op thromboembolic events or subsequent device infection over 30 days of follow-up. None of the patients required lead revision. One patient underwent CIED extraction after 11 months for an unrelated secondary device infection. Conclusion: Radiofrequency catheter ablation for AF can be safely performed without fluoroscopy in patients with CIED.

Abstract 14115: Multivariate Predictors of Long-Term Outcome From Ventricular Tachycardia Ablation in a Large Registry

Introduction: It remains difficult to identify clinical risk predictors of long-term outcomes from VT ablation. Hypothesis: We hypothesized that analysis of detailed clinical and laboratory features in a large registry may enable prediction of long-term outcomes from VT ablation. Methods: 623 consecutive patients enrolled in our VT ablation registry with 50 prespecified features included in this study. Ablation strategy was left to the discretion of each operator based on each clinical scenario, and included entrainment, activation mapping, substrate modification or a combination of these strategies. Patients were followed up for 3 years. Recurrent VT (&gt;30 seconds, appropriate device therapy or repeat ablation) or death were determined by clinical follow-up plus natural language processing of device interrogation. Results: Follow-up was available in N=596 (age 58.7±14.8y, 32.3% female). The overall VT-free survival was 65.3% at 1Y and 50.4% at 3Y, and was lower in patients with cardiomyopathy, particularly if ischemic (Figure). There was substantial inter-patient variability. Multivariate predictors of 3-Y VT-free survival (Table) were heart failure and systolic dysfunction (Hazard Ratio [HR]: 2.01, P &lt;0.0001), chronic kidney disease (HR: 1.70, P =0.0004), obstructive sleep apnea (HR: 1.36, P=0.0307), and serum sodium (HR: 0.89, P=0.0506) and calcium (HR: 0.85, P =0.0045). 1-Y predictors were similar. Conclusion: We identify novel clinical features of 1- and 3-year VT ablation outcomes in a large well characterized registry. These combinations of clinical and laboratory factors may guide procedural planning, and should be validated in other registries.

Incidence and clinical impact of tachyarrhythmic events following transcatheter aortic valve replacement: A review.

Transcatheter aortic valve replacement (TAVR) is well established for treating severe symptomatic aortic stenosis. Whereas broad information on the epidemiology, clinical implications, and management of bradyarrhythmias after TAVR is available, data about tachyarrhythmic events remain scarce. Despite the progressively lower risk profile of TAVR patients and the improvement in device characteristics and operator skills, approximately 10% of patients develop new-onset atrial fibrillation (NOAF) after TAVR. The proportion of patients in whom NOAF actually corresponds to previously undiagnosed silent atrial fibrillation (AF) has not been properly determined. The transapical approach, the need for pre- or post- balloon dilation, and the presence of periprocedural complications have been associated with a higher risk of NOAF. Older age, left atrial volume, or worse functional class are patient-derived risk factors shared with preprocedural AF. NOAF after TAVR has been associated with poorer survival and a higher incidence of cerebrovascular events. However, patient management differs markedly among different centers, especially with regard to anticoagulation in patients with short-duration AF episodes detected in the periprocedural setting and in cases of silent NOAF detected during continuous electrocardiographic (ECG) monitoring. Evidence about ventricular arrhythmias is even more scarce than for AF. Some case reports of sudden cardiac death after TAVR in patients with a pacemaker have identified ventricular tachycardia or ventricular fibrillation in device interrogation. TAVR has been shown to reduce the arrhythmic burden, but a significant proportion of patients (16%) present with complex premature ventricular complex arrhythmias within the year after TAVR. Whether these events are related to poorer outcomes is unknown. Continuous ECG monitoring after TAVR may help describe the frequency, risk factors, and prognostic implications of tachyarrhythmias in this population.