Implantable loop recorders in patients with Brugada syndrome: the BruLoop study.

BACKGROUND AND AIMS: Available data on continuous rhythm monitoring by implantable loop recorders (ILRs) in patients with Brugada syndrome (BrS) are scarce. The aim of this multi-centre study was to evaluate the diagnostic yield and clinical implication of a continuous rhythm monitoring strategy by ILRs in a large cohort of BrS patients and to assess the precise arrhythmic cause of syncopal episodes. METHODS: A total of 370 patients with BrS and ILRs (mean age 43.5 ± 15.9, 33.8% female, 74.1% symptomatic) from 18 international centers were included. Patients were followed with continuous rhythm monitoring for a median follow-up of 3 years. RESULTS: During follow-up, an arrhythmic event was recorded in 30.7% of symptomatic patients [18.6% atrial arrhythmias (AAs), 10.2% bradyarrhythmias (BAs), and 7.3% ventricular arrhythmias (VAs)]. In patients with recurrent syncope, the aetiology was arrhythmic in 22.4% (59.3% BAs, 25.0% VAs, and 15.6% AAs). The ILR led to drug therapy initiation in 11.4%, ablation procedure in 10.9%, implantation of a pacemaker in 2.5%, and a cardioverter-defibrillator in 8%. At multivariate analysis, the presence of symptoms [hazard ratio (HR) 2.5, P = .001] and age >50 years (HR 1.7, P = .016) were independent predictors of arrhythmic events, while inducibility of ventricular fibrillation at the electrophysiological study (HR 9.0, P < .001) was a predictor of VAs. CONCLUSIONS: ILR detects arrhythmic events in nearly 30% of symptomatic BrS patients, leading to appropriate therapy in 70% of them. The most commonly detected arrhythmias are AAs and BAs, while VAs are detected only in 7% of cases. Symptom status can be used to guide ILR implantation.

Superior vena cava isolation using a pentaspline pulsed-field ablation catheter: feasibility and safety in patients undergoing atrial fibrillation catheter ablation.

AIMS: Superior vena cava (SVC) isolation during atrial fibrillation catheter ablation is limited by the risk of collateral damage to the sinus node and/or the phrenic nerve. Due to its tissue-specificity, we hypothesized the feasibility and safety of pulsed-field ablation (PFA)-based SVC isolation. METHODS AND RESULTS: One hundred and five consecutive patients undergoing PFA-based AF catheter ablation were prospectively included. After pulmonary vein isolation (±posterior wall isolation and electrical cardioversion), SVC isolation was performed using a standardized workflow. Acute SVC isolation was achieved in 105/105 (100%) patients after 6 ± 1 applications. Transient phrenic nerve stunning occurred in 67/105 (64%) patients but without phrenic nerve palsy at the end of the procedure and at hospital discharge. Transient high-degree sinus node dysfunction occurred in 5/105 (4.7%) patients, with no recurrence at the end of the procedure and until discharge. At the 3-month follow-up visit, no complication occurred. CONCLUSION: SVC isolation using a pentaspline PFA catheter is feasible and safe.

Incidence of ventricular arrhythmias related to COVID infection and vaccination in patients with Brugada syndrome: Insights from a large Italian multicenter registry based on continuous rhythm monitoring.

INTRODUCTION: Brugada syndrome (BrS) has a dynamic ECG pattern that might be revealed by certain conditions such as fever. We evaluated the incidence and management of ventricular arrhythmias (VAs) related to COVID-19 infection and vaccination among BrS patients carriers of an implantable loop recorder (ILR) or implantable cardioverter-defibrillator (ICD) and followed by remote monitoring. METHODS: This was a multicenter retrospective study. Patients were carriers of devices with remote monitoring follow-up. We recorded VAs 6 months before COVID-19 infection or vaccination, during infection, at each vaccination, and up to 6-month post-COVID-19 or 1 month after the last vaccination. In ICD carriers, we documented any device intervention. RESULTS: We included 326 patients, 202 with an ICD and 124 with an ILR. One hundred and nine patients (33.4%) had COVID-19, 55% of whom developed fever. Hospitalization rate due to COVID-19 infection was 2.76%. After infection, we recorded only two ventricular tachycardias (VTs). After the first, second, and third vaccines, the incidence of non-sustained ventricular tachycardia (NSVT) was 1.5%, 2%, and 1%, respectively. The incidence of VT was 1% after the second dose. Six-month post-COVID-19 healing or 1 month after the last vaccine, we documented NSVT in 3.4%, VT in 0.5%, and ventricular fibrillation in 0.5% of patients. Overall, one patient received anti-tachycardia pacing and one a shock. ILR carriers had no VAs. No differences were found in VT before and after infection and before and after each vaccination. CONCLUSIONS: From this large multicenter study conducted in BrS patients, followed by remote monitoring, the overall incidence of sustained VAs after COVID-19 infection and vaccination is relatively low.

Papillary muscle ventricular ectopy ablation in a malignant mitral valve prolapse: Ablation in Malignant Mitral Valve Prolapse: Ablation in Malignant Mitral Valve Prolapse.

Patients with mitral valve prolapse (MVP) have a heterogeneous clinical spectrum, ranging from benign to severe clinical presentations such as sudden cardiac death (SCD). Some of the markers of "arrhythmic MVP" include inverted/biphasic T-waves, QT prolongation, and polymorphic premature ventricular contractions (PVCs) originating from the left ventricular outflow tract and papillary muscles (PMs). The genesis of arrhythmias in MVP recognizes the combination of the substrate (fibrosis) and the trigger (mechanical stretch). Therefore, ablation of ventricular arrhythmias originating from PMs in a patient with MVP can be considered an adjunctive strategy to lower the arrhythmic burden and reduce the risk of ICD shocks.

Endomyocardial biopsy guided by intracardiac echocardiography as a key step in intracardiac mass diagnosis.

BACKGROUND: Based on a plenty of different applications, intracardiac echocardiography (ICE) is now a well-established technology in complex electrophysiological procedures. Recently, ICE has become the most widely used ultrasound-based imaging tool to guide diagnostic endomyocardial biopsy (EMB). EMB of cardiac mass guided by ICE is an interesting application of ICE. Allowing a correct positioning of the bioptome, ICE reduce the procedure-related risks and the need of a diagnostic open-chest procedure reserving the more invasive approach to selected cases. CASE PRESENTATION: Hereby we report a case series of right ventricular masses in which the EMB was safely and effectively performed under ICE guidance giving essential information for planning the therapeutic strategy. CONCLUSIONS: The diagnosis of both metastatic and primary cardiac tumors relies on the histopathological analyses. The endomyocardial biopsy is a valuable tool for preoperative diagnosis and surgical planning of intracardiac masses suspected for tumors. In our experience, the use of ICE for right ventricle EMB of an intracardiac mass is an attractive modality thanks to the precise localization of the cardiac structures and the ability to guide bioptic withdrawal in the target area.

Non-laser percutaneous extraction of pacemaker and defibrillation leads: a decade of progress.

AIMS: Non-laser-based methods are safe in lead extraction but in the past have been less effective than laser methods. In the past decade, new equipment has been introduced including the Evolution® Mechanical Dilator Sheath and the Evolution® RL. We sought to determine the impact of new equipment on outcome in mechanical lead extraction. METHODS AND RESULTS: We considered 288 consecutive patients (age 66 ± 18 years) who underwent transvenous lead extraction (TLE) of 522 leads in the decade to the end of 2014. Three groups were identified: Group 1 (pre-Evolution® period, 76 patients, 133 leads), Group 2 (original Evolution® period, 115 patients, 221 leads), and Group 3 (Evolution® RL period, 97 patients, 168 leads). The age of leads was significantly greater in Groups 2 and 3 (6.2 ± 4.4 and 6.1 ± 5.4 years vs.4.7 ± 4.5, P < 0.05) as was the proportion of implantable cardioverter defibrillator leads (27.2 and 28.9 vs. 14.3%, P < 0.05). The groups were similar in the number of leads extracted per patient. Despite the increasing complexity of the systems extracted, complete extraction was achieved in a progressively greater proportion of leads (88.0% in Group 1, 95.5% in Group 2, and 97.6% in Group 3, P < 0.05), and procedure duration was similar. The proportion of leads for which femoral access was required was greater in Group 3 (11%, 18/164) compared with Group 2 (3%, 7/211), P = 0.006. The only major complications were a post-procedure subacute tamponade in Group 1 and an oesophageal injury related to transoesophageal echocardiography in Group 3. CONCLUSION: With current equipment, mechanical extraction provides a good combination of efficacy and safety.

Contrast Dye ICE Cap Embolization Using the Third-Generation Cryoballoon.

Cryoballoon ablation is a widely diffuse technology to perform paroxysmal atrial fibrillation ablation. The new generation cryoballoon catheters have been redesigned in order to improve the cooling capability. During cryoballoon ablation, it is not unusual to observe the formation of a contrast dye ice cap on top of the balloon itself. The automated balloon deflation before dissolution of the ice cap may increase the risk of embolization of large ice-mixed-contrast crystals in the systemic circulation. In the case hereby reported, we describe an uneventful embolization of this contrast dye ice cap in the systemic circulation.

Concomitant cryoballoon ablation and percutaneous closure of left atrial appendage in patients with atrial fibrillation.

AIMS: Pulmonary veins (PVs) isolation is the cornerstone of atrial fibrillation (AF) ablation and can be achieved either by conventional radiofrequency ablation or by cryoenergy. Left atrial appendage (LAA) closure has been proposed as alternative treatment to vitamin K antagonists (VKA). We aimed to evaluate the feasibility of combining cryoballoon (CB) ablation and LAA occlusion in patients with AF and a high thromboembolic risk or contraindication to antithrombotic therapy. METHODS AND RESULTS: Thirty-five patients (28 males, 74 ± 2 years) underwent CB ablation. Left atrial appendage occlusion was carried out by using two occluder devices (Amplatz Cardiac Plug, ACP, St. Jude Medical, MN, USA, in 25 patients; Watchman, Boston Scientific, MA, USA, in 10 patients). Thirty patients (86%) had previous stroke/TIA episodes, 6 patients (17%) had major bleeding while on VKA therapy, and 7 patients (20%) had inherited bleeding disorders. Over the follow-up (24 ± 12 months), atrial arrhythmias recurred in 10 (28%) patients. Thirty patients (86%) had complete sealing; 5 patients (14%) showed a residual flow (<5 mm) at first transoesophageal echocardiography (TEE) check, while at 1-year TEE residual flow was detected in 3 patients. In 13 patients (37%), VKA therapy was immediately discontinued. Six patients (17%) received novel oral anticoagulants treatment and then discontinued 3 months thereafter. No device-related complications or clinical thromboembolic events occurred. CONCLUSION: Combined CB ablation and LAA closure using different devices appears to be feasible in patients with non-valvular AF associated with high risk of stroke or contraindication to antithrombotic treatment.

Ventricular arrhythmias in aortic valve stenosis before and after transcatheter aortic valve implantation.

AIMS: Transcatheter aortic valve implantation (TAVI) is a therapeutic treatment for patients with severe aortic stenosis (AS) at high surgical risk. Although the procedure is associated with a reduction in total mortality, there are no data regarding changing in the incidence of premature ventricular contractions (PVCs) and ventricular arrhythmias (VAs) after TAVI. The aim of this study was to assess the incidence of VAs before and after TAVI. METHODS AND RESULTS: We enrolled 237 patients who underwent TAVI at our centre. Ninety-one patients were excluded for the following reasons: presence of prior permanent pacemaker (PPM) (n = 20), new PPM implant after TAVI (n = 48), death during the follow-up period (n = 16), and lost at follow-up (n = 7). Finally, 146 patients were included in our analysis. The presence of VAs was evaluated in all patients recording a 24 h Holter monitoring before the procedure and after 1 and 12 months. Ventricular arrhythmias were classified according to a modified Lown grading system. Before the procedure, isolates PVCs (grade 1-2 of Lown grading system) were present in 34.9% of patients (n = 51). Complex PVCs (grade 3-4a-4b of Lown grading system) were present in 48.6% of the population (multifocal PVCs in 32 patients, 21.9%; pairs in 25 patients, 17.1%; ventricular tachycardia in 14 patients, 9.6%). One month after the procedure, we observed statistically significant incidence decrease of arrhythmias of grade 3 (from 21.9 to 17.1%) and grade 4 (pairs from 17.1 to 12.3%; ventricular tachycardia from 9.6 to 4.8%). After 12 months, there was a further significant reduction in the frequency and severity of PVCs. In particular, 45.8% of patients had isolates PVCs (<30 in all given hours of monitoring in 45 patients, 30.8%; higher than 30 in any hour of monitoring in 22 patients, 15%) while the frequency of complex arrhythmias was reduced to 16.4% (multifocal PVCs in 13 patients, 9%; couplets 8 patients, 5.5% and ventricular tachycardia in 3 patients, 2.0%). The difference was statistically significant (P < 0.01). CONCLUSION: This study indicates that VAs are common in patients with AS. We observed a significant decrease in the incidence and severity of PVCs since the first month after TAVI. Furthermore, after 1 year follow-up there was a further and significant reduction in the frequency of complex PVCs. This may be related to the benefits determined by valve replacement on left ventricular function.

An alternative transseptal intracardiac echocardiography strategy to guide left atrial appendage closure: the first described case.

Transesophageal echocardiography (TEE) is the standard imaging technique to guide device implantation for left atrial appendage (LAA) closure. Unfortunately, TEE was contraindicated in this patient due to the high risk of variceal hemorrhage. Critical information about the exact anatomic characteristics of the LAA can be obtained using intracardiac echocardiography (ICE). However, standard right-side views do not allow a complete visualization of the LAA: in particular, a reliable left circumflex coronary artery short axis view, relevant for device positioning, is not always achievable. Transseptal views of the LAA with ICE might be used in planning an appropriate intervention strategy for patients who are not suitable for TEE imaging.

An Energy Minimization Approach to Twinning with Variable Volume Fraction.

In materials that undergo martensitic phase transformation, macroscopic loading often leads to the creation and/or rearrangement of elastic domains. This paper considers an example involving a single-crystal slab made from two martensite variants. When the slab is made to bend, the two variants form a characteristic microstructure that we like to call "twinning with variable volume fraction." Two 1996 papers by Chopra et al. explored this example using bars made from InTl, providing considerable detail about the microstructures they observed. Here we offer an energy-minimization-based model that is motivated by their account. It uses geometrically linear elasticity, and treats the phase boundaries as sharp interfaces. For simplicity, rather than model the experimental forces and boundary conditions exactly, we consider certain Dirichlet or Neumann boundary conditions whose effect is to require bending. This leads to certain nonlinear (and nonconvex) variational problems that represent the minimization of elastic plus surface energy (and the work done by the load, in the case of a Neumann boundary condition). Our results identify how the minimum value of each variational problem scales with respect to the surface energy density. The results are established by proving upper and lower bounds that scale the same way. The upper bounds are ansatz-based, providing full details about some (nearly) optimal microstructures. The lower bounds are ansatz-free, so they explain why no other arrangement of the two phases could be significantly better.

Micro-Costing Analysis for the Treatment of Atrial Fibrillation: An Economic Evaluation of the First Italian Experience of Same-Day Discharge Protocol for Cryoballoon Atrial Fibrillation Ablation.

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia, and its prevalence is expected to increase further due to the aging population, increasing prevalence of risk factors, improving detection methods, and broadening of catheter ablation indications. Along with limited healthcare resources and bed availability, these reasons led to the development of a same-day discharge (SDD) protocol. The aim of this study was to evaluate the health and economic impact of a routine adoption of same-day discharge after cryoballoon AF ablation. Methods: Consecutive patients with symptomatic and drug-refractory AF scheduled for first-time AF ablation were screened, and if deemed suitable, the SDD protocol was proposed and, if accepted, enrolled in the protocol. Results: A total of 324 patients were screened, and 118 were considered eligible for the SDD pathway. Fifty-two patients accepted the SDD pathway and were included in this study. The analysis showed that the variation in resource consumption associated with cryoablation in SDD is equal to EUR 739.85/patient. The analysis showed that the main cost driver for ordinary hospitalization was represented by the hospital stay, which was calculated to be 36% of the total cost. In total, there was a cost reduction of EUR 38.472 thanks to optimized AF patient management from the standard recovery setting to SDD. Conclusions: SDD after cryoballoon ablation of AF is feasible in selected patients with a standardized protocol.

High-Power Short-Duration Posterior Wall Isolation in Addition to Pulmonary Vein Isolation in Persistent Atrial Fibrillation Ablation Using the New TactiFlex™ Ablation Catheter.

BACKGROUND: The TactiFlex™ ablation catheter, Sensor Enabled™ (Abbott, Minneapolis, MN, USA), is an open-irrigation radiofrequency (RF) ablation catheter with flexible tip technology. This catheter delivers high-power short-duration (HPSD) RF ablations and has been adopted for atrial fibrillation (AF) ablation. HPSD is well-established not only in pulmonary vein isolation (PVI) but also when targeting extra-pulmonary vein (PV) targets. This study aims to determine the safety, effectiveness, and acute outcomes of PVI plus posterior wall isolation (PWI) in patients with persistent atrial fibrillation (Pe-AF) using HPSD and the TactiFlex™ ablation catheter. METHODS: Consecutive patients who underwent the ablation of Pe-AF in our centre between February 2023 and February 2024 were prospectively enrolled in the study. All patients underwent PVI plus PWI using TactiFlex™ and the HPSD strategy. The RF parameters were 50 W on all the PV segments and the roof, and within the posterior wall (PW). Left atrial mapping was performed with the EnSite X mapping system and the high-density multipolar Advisor HD Grid, Sensor Enabled™ mapping catheter. We compared the procedural data using HPSD with TactiFlex™ (n = 52) vs. a historical cohort of patients who underwent PVI plus PWI using HPSD settings and the TactiCath ablation catheter (n = 84). RESULTS: Fifty-two consecutive patients were included in the study. PVI and PWI were achieved in all patients in the TactiFlex™ group. First-pass PVI was achieved in 97.9% of PVs (n = 195/199). PWI was obtained in all cases by delivering extensive RF lesions within the PW. There were no significant differences compared to the TactiCath group: first-pass PVI was achieved in 96.3% of PVs (n = 319/331). Adenosine administration revealed PV reconnection in 5.7% of patients, and two reconnections of the PW were documented. Procedure and RF time were significantly shorter in the TactiFlex™ group compared to the TactiCath group, 73.1 ± 12.6 vs. 98.5 ± 16.3 min, and 11.3 ± 1.5 vs. 23.5 ± 3.6 min, respectively, p < 0.001. The fluoroscopy time was comparable between both groups. No intraprocedural and periprocedural complications related to the ablation catheter were observed. Patients had an implantable loop recorder before discharge. At the 6-month follow-up, 76.8% of patients remained free from atrial arrhythmia, with no significant differences between groups. CONCLUSIONS: HPSD PVI plus PWI using the TactiFlex™ ablation catheter is effective and safe. Compared to a control group, the use of TactiFlex™ to perform HPSD PVI plus PWI is associated with a similar effectiveness but with a significantly shorter procedural and RF time.

Leadless pacemaker implantation following tricuspid interventions: multicenter collaboration of feasibility and safety.

BACKGROUND: Permanent pacing is often required following valve intervention (either surgical or percutaneous); however, tricuspid interventions pose specific challenges to conventional pacing. Therefore, leadless pacemaker (LP) implantation may be the preferred strategy when permanent pacing is required after tricuspid valve intervention. PURPOSE: To report periprocedural outcomes and follow-up of patients undergoing implantation of a LP system following tricuspid valve interventions. METHODS: Patients with previous tricuspid valve intervention at the time of attempted implantation of a LP (MicraTM, Medtronic, Minneapolis, MN, USA) were included. RESULTS: Between 2019 and 2022, 40 patients underwent LP implantations following tricuspid interventions in 5 large tertiary centers. The mean age was 68.9 ± 13.7 years, and 48% patients were male. The indication for pacing was as following: AVB in 27 (68%) patients, AF with slow ventricular response in 10 (25%) patients, and refractory rapid atrial fibrillation (AF) referred to AV junction ablation in 3 (7%) patients. Most of the patients received Micra VR (78%). The procedure was successful in all patients. The mean procedural time is 58 ± 32 min, and the median fluoroscopy time is 7.5 min. Electrical parameters were within normal range (threshold: 1.35 ± 1.2 V@0.24 ms, impedance: 772 ± 245 Ohm, R-wave: 6.9 ± 5.4 mV). No acute complications were observed. During a mean follow-up of 10 months, electrical parameters remained stable, and 4 deaths were occurred (not related to the procedure). CONCLUSION: A LP is a safe and efficient option following tricuspid valve interventions.

Continuous Rhythm Monitoring With Implanted Loop Recorders in Children and Adolescents With Brugada Syndrome.

BACKGROUND: Young (<18 years of age) patients with Brugada syndrome (BrS) are often under-represented in BrS studies and their management, especially related to syncopal episodes, remains unclear. OBJECTIVES: This study sought to describe the arrhythmia prevalence among young patients with BrS undergoing continuous rhythm monitoring by implantable loop recorder (ILR) and to assess the etiology behind syncope of undetermined origin. METHODS: A total of 147 patients with BrS with ILR were enrolled in 12 international centers and divided into pediatric (age <12 years; n = 77, 52%) and adolescents (age 13-18 years; n = 70, 48%). RESULTS: Mean age was 11.3 years, 53 patients (36.1%) were female, and 31 (21.1%) had spontaneous type 1 electrocardiograms. Over a median follow-up of 3.6 years (Q1-Q3: 1.6-4.8 years), an arrhythmic event was recorded in 33 patients (22.4%), mainly of nonventricular origin: 15 atrial (10.2%) and 16 bradyarrhythmic events (10.9%). Ventricular arrhythmias occurred in 4 patients, all with spontaneous BrS, and were fever-related in one-half. Among all patients with recurrence of syncope during follow-up, true arrhythmic syncope was documented in 5 (17.8%), and it was due to bradyarrhythmias or atrial arrhythmias in 3 cases (60%). CONCLUSIONS: Continuous rhythm monitoring with ILRs in young patients with BrS detects a broad range of arrhythmias. Ventricular arrhythmias occur predominantly in patients with spontaneous type 1 electrocardiograms and during fever. Despite the young age, bradyarrhythmias and atrial arrhythmias are frequent and represent the cause of arrhythmic syncope in 60% of patients. Young patients with BrS with syncope of undetermined origin may benefit from ILR implant.

Dexmedetomidine for sedation during epicardial ablation for ventricular tachycardia: a single-center experience.

BACKGROUND: Epicardial approach to ventricular tachycardia (VT) ablation is mainly performed under general anesthesia (GA). Although catheter manipulation and ablation in the epicardial space could be painful, GA lowers blood pressure and may interfere with arrhythmia induction and mapping, and the use of muscle relaxants precludes identification of the phrenic nerve (PN). Moreover, an anesthesiologist's presence is required during GA for the whole procedure, which may not always be possible. Therefore, we evaluated the feasibility and safety of epicardial VT ablations performed under conscious sedation using dexmedetomidine in our center. METHODS: Between January 2018 and January 2022, all patients who underwent epicardial VT ablation under continuous dexmedetomidine infusion were prospectively included in the study. All patients received premedication 30 min before the epicardial puncture with paracetamol (acetaminophen 10 mg/ml) 1000 mg and ketorolac 30 mg. Sedation protocol included an intravenous bolus of midazolam hydrochloride (0.03-0.05 mg/kg) followed by continuous infusion of dexmedetomidine (0.2-0.7 mcg/kg/h). In addition, an intravenous fentanyl citrate bolus (0.7-1.4 mcg/kg) was given for short-term analgesia, followed by a second dose repeated after 30 to 45 min. Sedation-related complications were defined in case of respiratory failure, severe hypotension, and bradycardia requiring treatment. RESULTS: Sixty-nine patients underwent epicardial or endo-epi VT ablation under conscious sedation and were included in the analysis. The mean age was 65.4 ± 12.1 years; forty-six patients were males (66.6%). All patients had drug-refractory recurrent VT. Forty-seven patients (68.1%) had non-ischemic cardiomyopathy (NICM), 13 patients (18.9%) had ischemic-cardiomyopathy (ICM), and 9 patients (13%) had myocarditis. Standard percutaneous sub-xiphoid access was attempted in all patients. Non-inducibility of any VT was achieved in 82.6% (9/9 myocarditis, 10/13 ICM, 38/47 NICM, n = 57/69 patients), inducibility of non-clinical VT in 13% (3/13 ICM, 6/38 NICM, n = 9/69 patients), and failure in 4.3% (3/38 NICM, n = 3/69 patients). Although we observed procedural-related complications in five patients (7.2%), one transient PN palsy, two pericarditis, and two vascular complications, those were not related to the conscious sedation protocol. No respiratory failure, severe hypotension, or bradycardia requiring treatment has been observed among the patients. CONCLUSIONS: Prompt availability of anesthesiology support remains crucial for complex procedures such as epicardial VT ablation. Continuous infusion of dexmedetomidine and administration of midazolam and fentanyl seem to be a safe and effective sedation protocol in patients undergoing epicardial VT ablation.

High-Power Short-Duration Lesion Index-Guided Posterior Wall Isolation beyond Pulmonary Vein Isolation for Persistent Atrial Fibrillation.

Background: High-power short-duration (HPSD) radiofrequency (RF) ablation has been adopted to improve atrial fibrillation (AF) ablation. Although the role of HPSD is well-established in pulmonary vein isolation (PVI), fewer data have assessed the impact of HPSD when addressing extra-pulmonary veins (PVs) targets. Therefore, this study aims to determine the safety, effectiveness, and acute outcomes of HPSD lesion index (LSI)-guided posterior wall isolation (PWI) in addition to PVI as an initial strategy in persistent atrial fibrillation (Pe-AF). Methods: Consecutive patients who underwent ablation of Pe-AF in our center between August 2021 and January 2022 were retrospectively enrolled. All patients' ablation strategy was PVI plus PWI using HPSD LSI-guided isolation. RF parameters included 50 W targeting LSI values of ≥5 on the anterior part of the PVs and anterior roofline and ≥4 for the posterior PVs aspect, bottom line, and within the posterior wall (PW). We compared the LSI values with and without acute conduction gaps after the initial first-pass PWI. Left atrial mapping was performed with the EnSite X mapping system and a high-density multipolar Grid-shaped mapping catheter. We compared the procedural characteristics using HPSD (n = 35) vs. a control group (n = 46). Results: Thirty-five consecutive patients were included in the study. PWI on top of PVI was achieved in all cases in the HPSD group. First-pass PVI was achieved in 93.3% of PVs (n = 126/135). First-pass roofline block was obtained in most patients (n = 31, 88.5%), while first-pass block of the bottom line was only achieved in 51.4% (n = 18). There were no significant differences compared to the control group; first-pass PVI was achieved in 94.9% of PVs (n = 169/178), first-pass roofline block in 89.1%, and bottom-line in 45.6% of patients. To achieve complete PWI with HPSD, scattered RF applications within the PW were necessary. No electrical reconnection of the PW was found after adenosine administration and the waiting period. The procedure and RF times were significantly shorter in the HPSD group compared to the control group, with values of 116.2 ± 10.9 vs. 144.5 ± 11.3 min, and 19.8 ± 3.6 vs. 26.3 ± 6.4 min, respectively, p < 0.001. Fluoroscopy time was comparable between both groups. No procedural complications were observed. At the 12-month follow-up, 71.4% of patients remained free from AF, with no differences between the groups. Conclusions: HPSD LSI-guided PWI on top of PVI seems effective and safe. Compared to a control group, HPSD is associated with similar rates of first-pass PWI and PVI but with a shorter procedural and RF time.

Extensive Posterior Wall Isolation on Top of Pulmonary Vein Isolation Guided by Ablation Index in Persistent Atrial Fibrillation Ablation.

BACKGROUND: Durable pulmonary vein isolation (PVI) is recommended for symptomatic paroxysmal atrial fibrillation (AF) treatment, but it has been demonstrated that it may not be enough to treat persistent AF (Pe-AF). Therefore, posterior wall isolation (PWI) is among the strategies adopted on top of PVI to treat Pe-AF patients. However, PWI using contiguous and optimized radiofrequency lesions remains challenging, and few studies have evaluated the impact of the Ablation Index (AI) on the efficacy of PWI. Moreover, previous papers did not evaluate arrhythmia recurrences using continuous monitoring. METHODS: This is a prospective, observational, single-center study on patients affected by Pe-AF undergoing treated PVI plus AI-guided PWI. Procedures were performed using the CARTO mapping system, SmartTouch SF ablation catheter, and PentaRay multipolar mapping catheter. The AI settings were 500-550 for the anterior PV aspect and roofline, while the settings were 450-500 for the posterior PV aspect, bottom line, and/or PW lesions. All patients received an implantable loop recorder (ILR). All patients underwent clinical evaluation in the outpatient clinic at 1, 3, 6, 12, 18, and 24 months. A standard 12-lead ECG was performed at each visit, and device data from the ILR were reviewed to assess for arrhythmia recurrence. RESULTS: Between January 2021 and December 2021, forty-one consecutive patients underwent PVI plus PWI guided by AI at our center and were prospectively enrolled in the study. PVI was achieved in all patients, first-pass roofline block was obtained in 82.9% of the patients, and first-pass block of the bottom line was achieved in 36.5% of the patients. In 39% of the patients, PWI was not performed with a "box-only" lesion set, but with scattered lesions across the PW to achieve PWI. AI on the anterior aspect of the left PVs was 528 ± 22, while on the posterior aspect of the left PVs, it was 474 ± 18; on the anterior aspect of the right PVs, it was 532 ± 27, while on the posterior aspect of the right PVs, it was 477 ± 16; on the PW, AI was 468 ± 19. No acute complications occurred at the end of the procedure. After the blanking period, 70.7% of the patients reported no arrhythmia recurrence during the 12-month follow-up period. CONCLUSIONS: In patients with Pe-AF undergoing catheter ablation, PWI guided by AI seems to be an effective and feasible strategy in addition to standard PVI.