Lorenzo Bartoli

Aims: Temporary reprogramming of dual-chamber (DDD) pacemakers to non-synchronous ventricular modes (VVI/VVIR) may be required in selected clinical scenarios, but short-term consequences of abrupt atrioventricular (AV) synchrony loss remain incompletely characterized. Leveraging a unique natural experiment, this study aimed to quantify the clinical and echocardiographic consequences of temporary VVI/VVIR pacing in patients in sinus rhythm chronically adapted to DDD stimulation. Methods and results: In this prospective observational study, 93 patients (79.9±16.0 years; 63.4% AV block) with recalled DDD pacemakers were reprogrammed to VVI/VVIR for 6 months, followed by DDD restoration. Serial assessments included echocardiography, BNP, and 6-minute walk test. Primary endpoints were changes in left ventricular ejection fraction (LVEF) and heart failure (HF) hospitalizations; secondary endpoints included echocardiographic remodelling parameters, functional capacity, quality of life, and atrial fibrillation. Clinical events were tracked for 12 months. Ventricular pacing remained >88% throughout. During the VVI/VVIR period, HF hospitalizations increased compared with the subsequent DDD restoration period (22.6% vs 6.7%, p<0.001). This was accompanied by adverse echocardiographic remodelling, a decline in LVEF from 57.3% to 53.0% (p<0.001), and a marked BNP increase from 155 to 260 pg/ml (p<0.001). After DDD restoration, clinical and structural recovery was incomplete: LVEF improved to 54.8% and BNP decreased to 210 pg/ml, but both remained significantly worse than baseline (p<0.05). Conclusion: Temporary loss of AV synchrony in chronically DDD-paced patients was associated with rapid, severe, and only partially reversible clinical and echocardiographic deterioration. These findings underscore that continuous AV synchrony is a critical determinant of clinical stability.

Background: Catheter ablation is a validated treatment for ventricular arrhythmias (VA), but conventional radiofrequency (RF) energy may cause collateral injury due to non-selective thermal damage. Pulsed Field Ablation (PFA), a non-thermal modality based on irreversible electroporation, offers myocardial tissue selectivity and enhanced safety. While PFA is widely adopted for atrial arrhythmias’ ablation, its application in the ventricles remains an evolving frontier. Methods: We report a single-center experience using the Centauri PFA system integrated with a focal, contact-force sensing irrigated catheter (Tacticath™ SE, Abbott Laboratories, St. Paul, MN, USA) in four consecutive patients with drug-refractory VA. Two patients presented with frequent premature ventricular complexes (PVC) arising from the right and left ventricular outflow tract, respectively, while two had ischemic cardiomyopathy with recurrent scar-related ventricular tachycardia (VT). All procedures were guided by high-density mapping using the EnSite X system (Abbott Laboratories, St. Paul, MN, USA). Procedural safety, acute efficacy, and early follow-up outcomes were assessed. Results: All ablations achieved acute procedural success without complications. In both PVC cases, PFA led to immediate and complete suppression of ectopy, with a ≥95% reduction in arrhythmic burden at 12- and 9-months follow-up, respectively. In the VT cases, the arrhythmogenic substrate was effectively modified, rendering the clinical VT non-inducible. ICD interrogation during a 9-month follow-up showed complete absence of recurrent sustained VT. No coronary spasm, atrioventricular block, pericardial effusion, or other adverse events occurred. Conclusions: In this initial experience, focal PFA using a contact-force sensing catheter appeared feasible and effective for both focal and scar-related VA. This system provides an intuitive workflow similar to RF ablation. While our data suggest a favourable safety profile, larger studies are required to definitively confirm safety margins near critical structures.

Background/Objectives: Cardiac resynchronization therapy with defibrillator (CRT-D) is a well-established therapy for patients with heart failure (HF) and intraventricular conduction delays, but a non-negligible risk of infection and of lead functionality loss overtime is related to intravascular hardware. The novel DX system enables atrial sensing through a floating dipole integrated into the ICD lead, reducing the intravascular burden. In this prospective non-randomized study, we aimed to evaluate the safety and efficacy of a two-lead DX-based CRT system compared to a conventional three-lead (3L) CRT-D system. Methods: A total of 210 patients meeting CRT indications and no signs of sick sinus syndrome (SSS) (baseline HR ≥ 45 bpm, or at least 85 bpm at 6 min walking test) were enrolled. Patients were assigned to either the CRT-DX or conventional 3L CRT-D group. The primary endpoint was a composite clinical response, defined as the freedom from cardiovascular death, HF hospitalization, or new-onset atrial fibrillation (AF). Results: After a mean follow-up of 46.5 ± 1.9 months, both groups had comparable clinical and instrumental outcomes. CRT-DX patients exhibited higher atrial sensing amplitudes and no significant differences in loss of lead function. Conclusions: In conclusion, the CRT-DX system provides equivalent clinical and echocardiographic benefits compared to conventional CRT-D in patients without an indication for atrial pacing. This supports the use of the DX system as a safe and effective alternative in the majority of CRT recipients.

A significant portion of embolic strokes occurs without documented atrial fibrillation (AF), challenging the traditional paradigm of cardioembolism. This review addresses the emerging concept of “atrial cardiopathy” as a distinct clinical entity—an underlying atrial substrate abnormality, characterized by fibrosis and dysfunction, that promotes thromboembolism independent of AF. We posit that AF is often a late-stage manifestation of atrial cardiopathy, not the sole trigger for thrombosis. This paper synthesizes the growing evidence linking biomarkers of atrial cardiopathy to Embolic Stroke of Undetermined Source (ESUS). This new framework has profound clinical implications, suggesting a shift from arrhythmia detection to assessing atrial substrate health for stroke risk stratification. Recognizing atrial cardiopathy is fundamental for developing novel “upstream” therapies, such as targeted anticoagulation, aimed at preventing both AF and its devastating thromboembolic consequences. This review critically evaluates the evidence and translational gaps in the field, synthesizing the emerging role of advanced computational modeling as a key future tool for personalized risk stratification.

Introduction: Managing atrial fibrillation in kidney transplant patients poses a challenge for both nephrologists and cardiologists. Data regarding the safety and efficacy of catheter ablation in this patient’s cohort is scarce. Methods and results: In this two-center prospective study, we included all consecutive kidney transplant patients who underwent atrial fibrillation ablation between April 2017 and March 2022. A 1:3 propensity score matching created a control group of non-transplant AF patients undergoing ablation. We included 16 kidney transplant patients and 48 matched controls. Ablation was successful in all patients. The periprocedural complication rate (6.3% in the kidney transplant group vs. 6.3% in the control group, p value = 1) did not differ between the two groups. One transplant patient experienced graft dysfunction after a complication. At 18 months, AF recurrence-fee rates were 69% in the transplant group and 70.1% in controls (p = 0.95). By the last follow-up, all transplant patients had discontinued antiarrhythmic drugs, while 19.6% of the patients in the control group were treated with antiarrhythmic drugs (p = 0.09). Kidney function in the transplant group remained stable (eGFR 32 [23.8, 40.5] ml/min/1.73 m² before vs. 34 [29.8, 38] ml/min/1.73 m² at last follow up, p = 0.93). Conclusions: This study demonstrates that catheter ablation is a viable option for treating AF in kidney transplant patients, with comparable outcomes to non-transplanted individuals. Discontinuing antiarrhythmic drugs reduces drug interaction risks, but minimizing procedural complications remains critical to preserving graft function. Graphical

Background: Pulmonary vein isolation (PVI) with the use of an endoscopic laser balloon (ELB) is an alternative option for catheter ablation of atrial fibrillation (AF). The third-generation system has several improvements, including the novel RAPID mode (RM), potentially allowing a one-shot, continuous, circumferential laser lesion for PVI. Objective: In an international, multicentric cohort, we assessed the third-generation ELB’s safety, efficacy, and long-term effectiveness. We also focused on the learning curve (LC) and the use of RM. Methods: Between June 2019 and December 2022, we prospectively obtained data on all the patients who consecutively underwent ablation of AF using the third-generation ELB in eight Italian and one German hospital. Each operator attempted to use the RM to the maximum extent in every procedure. Follow-up (FU) visits were scheduled at 3, 6, 12 and 24 months and included a Holter-ECG of 24 hours or, if the patient was a carrier, a device interrogation (implantable loop recorder or two-chamber/three-chamber pacemaker/defibrillator). For FU analysis, we included patients with data available after the blanking period (the first 90 days after the procedure). We analysed the LC, comparing the outcomes of the first fifteen patients of each centre with the remaining patients. In addition, we investigated the impact of an extensive use of the RM (at least 90% of all PV circumferences) on the procedural and FU outcomes. Results: we enrolled 427 patients. Of these, 328 had a FU >90 days. The mean total procedural and fluoroscopic times were 105 (66-150) and 17 (10-28) minutes, respectively. Serious adverse procedural events occurred in 11 patients (2.6 %) as follows: 3 periprocedural transient ischaemic attacks, 4 pericardial tamponades, 1 persistent phrenic nerve palsy and 3 severe vascular complications. The mean FU period was of 365 days (194-533). AF recurrence-free rate was 76.7% (95% CI, 70.8%-81.5%) at 12 months. Median RM use was 94% (81-100) of the PVs circumference. RM could be used for at least 90% of all PV circumferences in 188 (55.8%) patients, and the operators could perform an RM-only procedure in 82 (24.3%) patients. Patients treated after the LC or with extensive use of RM showed significantly reduced procedural times and rates of AF recurrence. In a multivariate analysis, the use of the RM was not an independent predictor of a lower recurrence rate at FU, demonstrating only a tendency toward significance (86.0% [77.3-91.6] vs 71.3% [61.3-79.2], HR 0.52, CI 0.26-1.07, p 0.075). Conclusion: In this prospective, multicentre, international registry of patients treated with the third-generation ELB, the system proved efficient, safe, and effective. Completing the LC and using the RM reduced procedural time and arrhythmia recurrence. However, using RM was not an independent predictor of a lower recurrence rate.

Objectives: Conduction system pacing (CSP) and atrioventricular junction ablation (AVJA) improve the outcomes in patients with symptomatic, refractory atrial fibrillation (AF). In this setting, AVJA can be performed simultaneously with implantation or in a second procedure a few weeks after implantation. Comparison data on these two alternative strategies are lacking. Methods: A prospective, multicentre, observational study enrolled consecutive patients with symptomatic, refractory AF undergoing CSP and AVJA performed in a single procedure or in two separate procedures. Data on the long-term outcomes and healthcare resource utilization were prospectively collected. Results: A total of 147 patients were enrolled: for 105 patients, CSP implantation and AVJA were performed simultaneously (concomitant AVJA); in 42, AVJA was performed in a second procedure, with a mean of 28.8 ± 19.3 days from implantation (delayed AVJA). After a mean follow-up of 12 months, the rate of procedure-related complications was similar in both groups (3.8% vs. 2.4%; p = 0.666). Concomitant AVJA was associated with a lower number of procedure-related hospitalizations per patient (1.0 ± 0.1 vs. 2.0 ± 0.3; p < 0.001) and with a lower number of hospital treatment days per patient (4.7 ± 1.8 vs. 7.4 ± 1.9; p < 0.001). Conclusions: Concomitant AVJA resulted as being as safe as delayed AVJA and was associated with a lower utilization of healthcare resources.

Over the years, pacemakers have evolved from a life-saving tool to prevent asystole to a device to treat heart rhythm disorders and heart failure, aiming at improving both cardiac function and clinical outcomes. Cardiac stimulation nowadays aims to correct the electrophysiologic roots of mechanical inefficiency in different structural heart diseases. This has led to awareness of the concealed risks of customary cardiac pacing that can inadvertently cause atrioventricular and inter-/intra-ventricular dyssynchrony, and has promoted the development of new pacing modalities and the use of stimulation sites different from the right atrial appendage and the right ventricular apex. The perspective of truly physiologic pacing is the leading concept of the continued research in the past 30 years, which has made cardiac stimulation procedure more sophisticated and challenging. In this article, we analyze the emerging evidence in favor of the available strategies to achieve an individualized physiologic setting in bradycardia pacing.