Objectives: Atrial fibrillation (AF) is the most common sustained arrhythmia associated with stroke, heart failure, and increased mortality. Due to its efficacy and safety, cryoballoon ablation (CBA) is widely accepted for rhythm control; however, long-term AF recurrence remains a challenge. Continuous monitoring with implantable loop recorders (ILRs) enhanced by artificial intelligence (AI) can detect both symptomatic and asymptomatic episodes, potentially optimizing patient management. This analysis assessed the long-term effectiveness of CBA in maintaining sinus rhythm and investigated the role of ILR-guided monitoring in enhancing therapeutic decisions. Methods: Data from 91 patients with paroxysmal or persistent atrial fibrillation (AF) who underwent pulmonary vein isolation using cryoballoon ablation at four Italian centers between April 2022 and April 2024 were analyzed. All patients received an insertable loop recorder (ILR) before or during hospitalization for ablation, allowing for the continuous remote monitoring of arrhythmias. Baseline demographics, procedural details, AF occurrence, AF burden (calculated as the total duration of all AF episodes occurring within a day and categorized by episode duration), therapeutic adjustments, and the effect of artificial intelligence (AI) on data processing were evaluated. Results: The cohort’s average age was 62.4 years, with 24.2% of participants being female. Physician-confirmed AF recurrence was noted in 26.7% of patients at 12 months and 49.5% at 24 months. The device data indicated a daily AF burden of ≥6 min in 47.2% at 12 months, with 25.9% surpassing 1 h. AI algorithms decreased false-positive alerts by 21%, resulting in an estimated saving of 19 clinician hours. In patients with pre-ablation ILR data, the median AF burden significantly decreased from 7% to 0.2% (p = 0.017). ILR-guided monitoring affected treatment adjustments, leading to the discontinuation of antiarrhythmic therapy in 36 patients and redo ablations in 8. Conclusions: Continuous ILR monitoring, combined with AI-driven analysis, enables the detection of AF recurrences and burden, thereby facilitating timely therapeutic adjustments.

Ventricular arrhythmias (VAs) are common and clinically important complications in patients supported by left ventricular assist devices (LVADs), occurring in up to 50% of cases within the first year after implantation. Despite the hemodynamic support provided by LVADs, VAs are linked to increased morbidity and mortality, primarily through recurrent implantable cardioverter defibrillator (ICD) shocks and right ventricular failure. The underlying mechanisms of VAs in this population are multifactorial, involving structural myocardial remodeling, device-related factors, and pre-existing arrhythmic substrates. Catheter ablation has become a valuable treatment option when antiarrhythmic drug therapy and device reprogramming are inadequate, though procedural timing (pre-, intra-, or post-implantation) and approaches remain under discussion. Epicardial access during LVAD surgery may provide advantages for selected patients, while ablation after implantation poses technical challenges due to altered anatomy and electromagnetic interference. This review offers a comprehensive overview of the epidemiology, pathophysiology, risk stratification, and management of VAs in LVAD recipients, emphasizing technical considerations, procedural safety, and clinical outcomes of catheter ablation. A multidisciplinary approach remains essential in guiding personalized treatment and optimizing outcomes for this complex population. Undergoing studies will provide more insight into optimal management of arrhythmias, particularly regarding the optimal timing of catheter ablation. The impact of new technologies such as non-invasive mapping alongside pre-procedural imaging needs also to be further evaluated.

Neuromuscular diseases (NMDs) encompass various hereditary conditions affecting motor neurons, the neuromuscular junction, and skeletal muscles. These disorders are characterized by progressive muscle weakness and can manifest at different stages of life, from birth to adulthood. NMDs, such as Duchenne and Becker muscular dystrophies, myotonic dystrophy, and limb–girdle muscular dystrophies, often involve cardiac complications, including cardiomyopathies and arrhythmias. Underlying genetic mutations contribute to skeletal and cardiac muscle dysfunction, particularly in the DMD, EMD, and LMNA genes. The progressive nature of muscle deterioration significantly reduces life expectancy, mainly due to respiratory and cardiac failure. The early detection of cardiac involvement through electrocardiography (ECG) and cardiac imaging is crucial for timely intervention. Pharmacological treatment focuses on managing cardiomyopathies and arrhythmias, with an emerging interest in gene therapies aimed at correcting underlying genetic defects. Heart transplantation, though historically controversial in patients with muscular dystrophies, is increasingly recognized as a viable option for individuals with advanced heart failure and moderate muscle impairment, leading to improved survival rates. Careful patient selection and management are critical to optimizing outcomes in these complex cases.

Adult congenital heart disease (ACHD) represents a significant portion of congenital anomalies, and with improved treatments leading to an increased life expectancy, its prevalence has been increasing over the past few decades. Nonetheless, a considerable number of patients with ACHD require cardiac rhythm management devices during their lifetime. Traditionally, transvenous pacemaker placement has been the standard mode of treatment for these patients. However, some patients with ACHD have anatomical barriers that obscure this mode of treatment. Leadless pacing systems (LPSs) have changed the field of pacing. Currently, two different LPSs are available. In a real-world setting, implanting an LPS in patients after tricuspid valve (TV) surgery seems to be a straightforward procedure with a low risk of complications, with patients showing no valvular dysfunction after the intervention. LPS implantation is an option to avoid device-related complications in patients with previous TV surgery. Moreover, it has been demonstrated that even the jugular approach seems as safe as the femoral approach and could be considered an alternative implantation method for LPSs. The Aveir VR leadless pacemaker is a helix LPS with unique features, such as its capacity as a dual-chamber leadless pacemaker, the ability to map electrical parameters before releasing the device, and its possibility of being retrievable. Hereby, we present the case of Ebstein’s anomaly, atrial septal defect closure, and previous TV surgery with symptomatic intermittent advanced atrioventricular block. This case illustrates that a transjugular approach for LPSs is also feasible in patients with ACHD.

Background Although leadless pacemakers have demonstrated satisfactory safety and efficacy, there is limited published data regarding the estimated lifespan in real word clinical scenarios. Methods Between May 2015 and September 2023, all consecutive patients who underwent implantation of a single-chamber leadless Micra pacemaker were included in the One Hospital ClinicalService project and systematically tracked through remote monitoring at 15 Italian cardiology sites. Data on procedures, complications, electrical parameters, and estimated battery longevity were collected at baseline and annually during follow-up (FU). Additionally, virtual battery longevity (VBL) was calculated as the sum of the actual battery life consumed and the predicted remaining longevity (VBL = months consumed + months predicted), providing an estimate of the device's total battery lifespan. Results Patient and device data were gathered from 391 patients. Over a median follow-up period of 33.9 months (with interquartile range from 17.5 to 52.0 months), one patient experienced battery depletion. When examining VBL across all patients, the median VBL at baseline was 172 months (with a I-III interquartile range of 146 to 200 months), and VBL remained consistent or greater from the time of implantation up to seven years post-implant. The strongest predictor of VBL depletion within 8 years was capture threshold at implant greater than 1 V @ 0.24 ms. Conclusion In clinical practice, leadless pacemakers appear to have a median expected longevity ranging from 14 to 17 years. Having a stimulation threshold less than or equal to 1 V @ 0.24 ms seems to be an excellent predictor of increased longevity.

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.

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.

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.

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.

BACKGROUND Multicenter ventricular tachycardia (VT) ablation studies have shown poorer outcomes compared with single-center experiences. This difference could be related to heterogeneous mapping and ablation strategies. OBJECTIVES This study evaluated a homogenous simplified catheter ablation strategy for different substrates and compared the results with those of a single referral center. METHODS This was a multicenter prospective VT ablation registry of patients with the following 4 causes of VT: previous myocardial infarction; previous myocarditis; arrhythmogenic right ventricular dysplasia; or idiopathic dilated cardiomyopathy. The procedural protocol included precise mapping and ablation steps with the combined endpoint of late potential (LP) abolition and noninducibility of VT. The long-term primary efficacy endpoint was freedom from VT. RESULTS A total of 309 patients were enrolled. LPs were present in 70% of patients and were abolished in 83%. At the end of the procedure 74% of LPs were noninducible. The primary combined endpoint of LP abolition and noninducibility was achieved in 64% of patients with LPs at baseline. Freedom from VT at 12 months was observed in 67% of patients. In the overall study group, VT inducibility was the only predictor of freedom from VT (P = 0.013). In patients with LPs, the VT recurrence rate was lower both for patients with complete LP abolition (P = 0.040) and for patients meeting the composite endpoint (P = 0.035). CONCLUSIONS A standardized VT mapping and ablation technique reproduced the procedural outcomes of a single referral center in a multicenter prospective study. LP abolition and noninducibility were effective in reducing VT recurrences in patients with 4 causes of cardiomyopathy. (Ventricular Tachycardia Ablation Registry; NCT03649022) (J Am Coll Cardiol EP 2023;9:836-847) (c) 2023 by the American College of Cardiology Foundation.

Multicenter ventricular tachycardia (VT) ablation studies have shown poorer outcomes compared with single-center experiences. This difference could be related to heterogeneous mapping and ablation strategies. This study evaluated a homogenous simplified catheter ablation strategy for different substrates and compared the results with those of a single referral center. This was a multicenter prospective VT ablation registry of patients with the following 4 causes of VT: previous myocardial infarction; previous myocarditis; arrhythmogenic right ventricular dysplasia; or idiopathic dilated cardiomyopathy. The procedural protocol included precise mapping and ablation steps with the combined endpoint of late potential (LP) abolition and noninducibility of VT. The long-term primary efficacy endpoint was freedom from VT. A total of 309 patients were enrolled. LPs were present in 70% of patients and were abolished in 83%. At the end of the procedure 74% of LPs were noninducible. The primary combined endpoint of LP abolition and noninducibility was achieved in 64% of patients with LPs at baseline. Freedom from VT at 12 months was observed in 67% of patients. In the overall study group, VT inducibility was the only predictor of freedom from VT (P = 0.013). In patients with LPs, the VT recurrence rate was lower both for patients with complete LP abolition (P = 0.040) and for patients meeting the composite endpoint (P = 0.035). A standardized VT mapping and ablation technique reproduced the procedural outcomes of a single referral center in a multicenter prospective study. LP abolition and noninducibility were effective in reducing VT recurrences in patients with 4 causes of cardiomyopathy. (Ventricular Tachycardia Ablation Registry; NCT03649022)

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.

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.

Several novel technologies allowing catheter ablation (CA) with a favorable safety/efficacy profile have been recently developed, but not yet extensively clinically tested in the setting of ventricular tachycardia CA. In this technical report, we overview technical aspects and preclinical/clinical information concerning the application of three novel CA technologies in the ventricular milieu: a pulsed field ablation (PFA) generator (CENTAURI™, Galaxy Medical) to be used with linear, contact force-sensing radiofrequency ablation catheters; a contact force-sensing radiofrequency ablation catheter equipped with six thermocouples and three microelectrodes (QDOT Micro™, Biosense-Webster), allowing high-resolution mapping and temperature-controlled CA; and a flexible and mesh-shaped irrigation tip, contact force-sensing radiofrequency ablation catheter (Tactiflex, Abbott). We also report three challenging VT cases in which CA was performed using these technologies. The CENTAURI system was used with the Tacticath™ (Abbott) ablation catheter to perform ventricular PFA in a patient with advanced heart failure, electrical storm, and a deep intramural septal substrate. Microelectrode mapping using QDOT Micro™ helped to refine substrate assessment in a VT patient with congenitally corrected transposition of the great arteries, and allowed the identification of the critical components of the VT circuit, which were successfully ablated. Tactiflex™ was used in two challenging CA cases (one endocardial and one epicardial), allowing acute and mid-term control of VT episodes without adverse events. The ideation and development of novel technologies initially intended to treat atrial arrhythmias and successfully implemented in the ventricular milieu is contributing to the progressive improvement in the clinical benefits derived from VT CA, making this procedure key for successful management of increasingly complex patients.

AbstractAimsThe safety and efficacy of leadless intracardiac-permanent pacemaker (L-PM) have been demonstrated in multiple clinical trials, but data on comparisons with conventional transvenous-permanent pacemaker (T-PM) collected in a consecutive, prospective fashion are limited. The aim of this analysis was to compare the rate and the nature of device-related complications between patients undergoing L-PM vs. T-PM implantation.Methods and resultsProspective, multicentre, observational project enrolling consecutive patients who underwent L-PM or T-PM implantation. The rate and nature of device-related complications were analysed and compared between the two groups. Individual 1:1 propensity matching of baseline characteristics was performed. A total of 2669 (n = 665 L-PM) patients were included and followed for a median of 39 months, L-PM patients were on average older and had more co-morbidities. The risk of device-related complications at 12 months was significantly lower in the L-PM group (0.5% vs. 1.9%, P = 0.009). Propensity matching yielded 442 matched pairs. In the matched cohort, L-PM patients trended toward having a lower risk of overall device-related complications (P = 0.129), had a similar risk of early complications (≤30 days) (P = 1.000), and had a significantly lower risk of late complications (>30 days) (P = 0.031). All complications observed in L-PM group were early. Most (75.0%) of complications observed in T-PM group were lead- or pocket-related.ConclusionIn this analysis, the risk of device-related complications associated with L-PM implantation tended to be lower than that of T-PM. Specifically, the risk of early complications was similar in two types of PMs, while the risk of late complications was significantly lower for L-PM than T-PM.

Background: Safety and efficacy of leadless pacemakers (L-PM) have been demonstrated in multiple clinical trials, but real-world data on patient selection, implantation technique, and peri-procedural patient management in a clinical practice setting are lacking. Methods: Consecutive patients undergoing L-PM implantation in 14 Italian centers were followed in a prospective, multicentre, observational project. Data on baseline patient characteristics, clinical indications, implantation procedure, and peri-procedural patient management were collected. The rate and nature of device-related complications were also recorded. Results: A total of 782 L-PM patients (68.4% male, 75.6 +/- 12.4 years) were included in the analysis. The main patients-related reason leading to the choice of implanting a L-PM rather than a conventional PM was the high -risk of device infection (29.5% of cases). The implantation success rate was 99.2%. The median duration of the procedure was 46 min. In 90% of patients the device was implanted in the septum. Of patients on oral anticoagulant therapy (OAT) (n = 498) the implantation procedure was performed without interrupting (17.5%) or transiently interrupting OAT without heparin bridging (60.6%). During a median follow-up of 20 months major device-related complications occurred in 7 patients (0.9%): vascular access-site complications in 3 patients, device malfunction in 2 patients, pericardial effusion/cardiac tamponade in one patient, device migration in one patient. Conclusions: In the real world setting of Italian clinical practice L-PM is often reserved for patients at high-risk of infection. The implantation success rate was very high and the risk of major complications was low. Peri -procedural management of OAT was consistent with available scientific evidence.

Abstract BackgroundHigh-definition multielectrode mapping is becoming the cornerstone of complex ablation procedures. Differently from traditional bipolar electrograms that have susceptibility to directionality, Omnipolar Technology (OT) provides voltage, timing, and activation direction assessments independent of catheter orientation by incorporating simultaneously acquired EGM signals from multiple directions. Case presentationA 62 years-old male with ischemic cardiomyopathy underwent VT ablation guided by the EnSite X 3D mapping system. The first procedure was performed without the OT, while for the redo, OT was available. The substrate map performed by using the OT was much more defined, and the LPs map showed residual activity. Of great interest, an area noted as a dense scar during the first procedure appeared to be outside the dense scar region at the redo. Complete elimination of LPs in this region made the VT not inducible. ConclusionsHigh-definition multipolar mapping using the HD Grid can be rapidly and accurately performed during complex substrate mapping and ablation, such as post-ischemic VT. In particular, omnipolar mapping provide rapid, high-density, orientation-independent assessment of the underlying atrial substrate. This case report has a unique nature considering that the same patient underwent the index procedure without OT and redo with OT.

Mice were injected intraperitoneally (i.p.) with 100% dimethyl sulfoxide (DMSO) or sterile saline (controls) for 36 days. The mice received 0.05 ml daily for one week, 0.025 ml every other day for the second week (because the DMSO-treated mice appeared weak), and 0.05 ml daily for 3 more weeks. All mice were immunized twice with sheep red blood cells (days 13 and 24), and bled twice by caudal incision (days 20 and 29). Hematocrits were significantly decreased (P less than or equal to 0.002) but still within the normal range. The primary and secondary antibody response to sheep red blood cells (SRBC), leukocyte counts, body weight, and the size of the heart, lungs, spleen, thymus, and kidneys were not affected. DMSO treatment resulted in significant liver enlargement (P = 0.02). It is concluded that this dose of DMSO is not deleterious to the humoral immune response in mice responding to a new antigen.

A high-definition mapping catheter has been introduced, allowing for bipolar recording along and across the spline with a rapid assessment of voltage, activation, and directionality of conduction. We aimed to evaluate differences in mapping density, accuracy, time, and consequently RF time between different mapping catheters used for ventricular tachycardia (VT) ablation. We enrolled consecutive patients undergoing VT ablation at our center. Patients were divided into the LiveWire 2-2-2 mm catheter (group A) and the HD Grid SE (group B). Primary endpoints were total RF delivery time, the number of points acquired in sinus rhythm and VT, and the scar area. Fifty-one patients were enrolled, 22 in group A and 29 in group B. More points were acquired in the Grid group in sinus rhythm (SR) and during VT (2060.78 ± 1600.38 vs. 3278.63 ± 3214.45, p = 0.05; 4201.13 ± 5141.61 vs. 10,569.43 ± 13,644.94, p = 0.02, respectively). The scar area was smaller in group B (Bipolar area, cm2 4.52 ± 2.72 vs. 2.89 ± 2.81, p = 0.05. Unipolar area, cm2 7.47 ± 4.55 vs. 5.56 ± 2.79, p = 0.03). Radiofrequency (RF) time was shorter in the Grid group (30.52 ± 13.94 vs. 22.16 ± 11.03, p = 0.014). LPs and LAVAs were eliminated in overall >93% of patients. No differences were found in terms of arrhythmia-free survival at follow-up. In conclusion, the use of a high-definition mapping catheter was associated with significantly shorter mapping time during VT and RF time. Significantly more points were acquired in SR and during VT. During remap, we also observed more LAVAs and LPs requiring further ablation.