AIMS:Atrial fibrillation (AF) is highly prevalent among cardiac amyloidosis (CA) patients and contributes significantly to their morbidity and mortality. Evidence regarding AF ablation efficacy and safety in CA patients remains limited. The aim of our study is to evaluate baseline characteristics, clinical course and outcomes of AF ablation in a series of patients with transthyretin (ATTR) or light-chain (AL) CA from a multicentre international registry. METHODS AND RESULTS:Patients with CA who underwent AF ablation were included. Co-primary endpoints were: (i) atrial arrhythmia (AA) recurrence; (ii) a composite endpoint of all-cause mortality and heart failure hospitalization (HFH). 109 patients (mean age 72.4 ± 7.4 years, females 17.4%, persistent AF 64.2%, ATTR 78%, AL 22%) were included. Radiofrequency, cryo-balloon and pulsed-field ablation were performed in 67%, 15% and 18% of patients, respectively; 49.5% received pulmonary vein isolation plus additional ablations. Low voltage zones were documented in 34 out of 44 patients undergoing electro-anatomical mapping (77.3%). During a median follow-up of 22.7 months, 63 patients (58.3%) experienced AA recurrence (32.4% persistent AF recurrence), with no significant differences between CA subtypes (ATTR 59.5% vs. AL 54.2%, log-rank P = 0.55). The composite endpoint of HFH and all-cause death occurred in 27 patients (25%). Recurrence of persistent AF was associated with three-fold higher risk (OR 2.9, P = 0.02) of the composite endpoint. CONCLUSION:CA patients undergoing AF ablation present high prevalence of persistent AF. Freedom from AA after AF ablation is achieved in 42% of patients after a two-year follow-up. Patients with persistent AF recurrence have a three-fold higher risk of HFH and death.

Introducción y objetivos El remodelado auricular izquierdo es frecuente en la miocardiopatía hipertrófica (MCH), y se asocia con la fibrilación auricular (FA) y episodios tromboembólicos. Sin embargo, los modelos actuales de predicción del riesgo de FA tienen un rendimiento limitado en la MCH. El índice de acoplamiento auriculoventricular izquierdo (LACI) es un marcador de imagen emergente que integra el tamaño auricular y las propiedades de llenado ventricular. El objetivo fue evaluar la asociación entre el LACI y la aparición de FA de novo, ataque isquémico transitorio o ictus isquémico en pacientes con MCH. Métodos Se realizó un análisis retrospectivo de 287 pacientes con MCH sin antecedentes de FA, ataque isquémico transitorio o ictus, estudiados mediante resonancia magnética cardiaca entre 2014 y 2022. Se midieron los volúmenes auricular y ventricular izquierdos, y se calculó el LACI como la relación entre el volumen mínimo auricular y el volumen telediastólico ventricular. Los pacientes se clasificaron en terciles de LACI. Se realizó un análisis de la deformación del corazón o strain auricular izquierdo. La asociación con un episodio compuesto (FA, ataque isquémico transitorio o ictus) se evaluó mediante modelos de Cox. Resultados Durante un seguimiento mediano de 60 meses, 51 pacientes (17,9%) presentaron el episodio compuesto. El tercil superior de LACI (≥ 36%) se asoció con un mayor riesgo de FA o episodios tromboembólicos (HR ajustada=2,88; IC95%, 1,27-6,51; p <0,001). El booster-strain auricular izquierdo también mostró una asociación independiente. Conclusiones En la MCH, el LACI y el booster-strain auricular izquierdo se asocian de forma independiente con la FA de novo y episodios tromboembólicos.

A 67-year-old man with recurrent syncope and chronic right bundle branch block underwent left bundle branch pacing for infra-Hisian atrioventricular block. Because a prior electrocardiogram showed a type 2 Brugada pattern, an ajmaline challenge was performed after device implantation using high-precordial lead positioning. The test unmasked a diagnostic type 1 Brugada pattern during both intrinsic and left bundle branch block-paced beats. This case illustrates that diagnostic Brugada repolarization abnormalities may remain recognizable despite altered ventricular activation associated with conduction system pacing.

BACKGROUND:The role of atrial pacing support is unclear in patients receiving cardiac resynchronization therapy-defibrillator (CRT-D) without sinus node dysfunction. METHODS:We conducted a randomized, parallel-group, noninferiority trial to evaluate whether a 2-lead CRT-D capable of atrial sensing (but no pacing) by a floating dipole on the right ventricular lead (CRT-DX) is not inferior to a 3-lead CRT-D with a conventional atrial lead. Between October 17, 2018, and March 5, 2024, a total of 636 patients (68±10 years old, 28.6% women) with standard CRT-D indication, optimized medical therapy, and resting sinus rate ≥45 beats/min were randomized 1:1 to CRT-DX (atrial tracking without atrial pacing mode 35 beats/min) or CRT-D (atrial tracking with atrial pacing mode 50 beats/min) at 23 Italian sites. A centralized block-randomization procedure stratified by site was used, with patients and primary outcome assessors blinded to treatment assignment. The primary end point was a 1-year composite of all-cause mortality, cardiovascular hospitalization, and lead-related complications (loss of functionality not correctable by device reprogramming). Secondary end points included each individual component of the primary end point separately, echocardiographic reverse remodeling, and 6-minute walk test distance at 12 months. RESULTS:The primary end point occurred in 41 (13.1%) patients in the CRT-DX group and 47 (15.6%) patients in the CRT-D group, corresponding to a hazard ratio of 0.82 (95% CI, 0.54-1.25). This confirmed noninferiority (prespecified relative margin of 1.20) in both the per-protocol (P=0.039) and intention-to-treat (P=0.044) analyses. Individual components showed no significant differences, except for lead complications related to right atrial functionality (4 [1.3%] patients in the CRT-DX group versus 13 [4.2%] patients in the CRT-D group; P=0.040). Reverse remodeling responders were 203 (77.5% of 262) patients receiving CRT-DX and 190 (76.3% of 249) patients receiving CRT-D (P=0.83). Walking distance did not differ between 2 study arms (404 versus 398 m; P=0.62). After a median follow-up of 2.4 years, only 1 patient receiving CRT-DX required implantation of a standard atrial lead. CONCLUSIONS:The 2-lead CRT-DX system without atrial pacing is noninferior to conventional 3-lead CRT-D, with fewer atrial lead-related complications. REGISTRATION:URL: https://www.clinicaltrials.gov; Unique identifier: NCT03587064.

Atrial fibrillation (AF) represents an emerging challenge in thalassemia due to the increasing life expectancy. However, data are limited, and management relies on guidelines for the general population. We conducted a multicenter retrospective study to assess the prevalence of AF in transfusion-dependent beta-thalassemia (beta-TDT). Nine centers, following 1389 patients, participated in the study; 188 subjects with a history of AF were included, 61% were males, and 73% splenectomized. The mean age at the first AF episode was 40 years. The prevalence of AF was 11.9%, reaching 31% in individuals older than 66 years. Among the known risk factors, the most common were diabetes, heart failure, and smoking. Regarding disease-specific factors, a history of cardiac iron overload was present in almost half of the patients before AF and in one-third at the time of the first event. Most subjects exhibited left atrial dilatation, which can result from anemia. Transcatheter ablation was performed in 26.6% without any complications, and 74.4% reported improvement in symptoms, the primary aim of the procedure. The stroke prevalence was 5.5%, rising to 7.9% when including transient ischemic attacks, with 88% of patients being splenectomized. The CHA2DS2-VASc score was low in more than half of the patients, and 9 events occurred during anticoagulant therapy. This study is the first to evaluate AF prevalence in beta-TDT, which is higher than in the general population. The CHA2DS2-VASc score has some limitations, and specific guidelines are necessary to provide optimal care for these patients.

BACKGROUND:Understanding how baseline conditions influence alerts and adverse events in patients with heart failure (HF) and cardiac implantable electronic devices (CIEDs) under remote monitoring (RM) is crucial for patient management. However, the impact of HF alerts on clinical outcomes remains poorly defined. OBJECTIVE:To assess the impact of HF alerts on adverse outcomes and to identify clinical trajectories based on individual baseline risk factors. METHODS:We conducted a single-center, retrospective study including HF patients implanted with a CIED and provided with RM. We modeled patients trajectories using a semi-Markov, four-state framework with six possible transitions, encompassing a HF score alert state, HF Hospitalization (HFH) state and all-cause death. Cox proportional hazards models assessed the effects of baseline covariates on transition rates and evaluated the impact of HF alert occurrence on outcomes, treated as time-dependent covariates. RESULTS:A total of 511 patients (median age 69.9 years [IQR 61.4-77.1]) were included. During a median follow-up of 1.8 years [IQR 0.7-3.9], 60 patients (11.7%) transitioned to an HF score alert state, of whom 6 (10%) and 12 (20%) respectively experienced an HFH and died without a prior HFH. From the baseline group, 29 patients (5.7%) transitioned directly to death and 53 patients (10.4%) had an HFH. Of the 59 total patients who experienced an HFH, 19 (32%) died during follow-up. The transition to a HF score alert state was significantly associated with all-cause death (HR 6.99, 95% CI 1.89-25.94; p = 0.004) while not statistically significant associated with HFH (HR 0.58, 95% CI 0.13-2.69; p = 0.65). CONCLUSIONS:Using a multistate model, we characterized clinical trajectories in HF patients and observed the effects of different covariates on transition rates.

BACKGROUND:Left bundle branch pacing (LBBP) restores physiological ventricular activation, yet its impact on left ventricular (LV) mechanical efficiency remains incompletely understood. OBJECTIVE:To compare LV mechanical efficiency during spontaneous rhythm and LBBP using myocardial work (MW) indices, and to evaluate the influence of QRS transition type. METHODS:In 115 patients enrolled in the prospective TREEBEARD study (NCT06324682), MW indices (i.e., global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE)) were measured before and after LBBP. Patients were classified according to QRS transition during decremental output as Left Bundle (LB) group (nonselective to selective LBB capture) or non-LB group (nonselective capture to LV septal pacing). RESULTS:Overall, LBBP achieved mechanical efficiency comparable to that observed during spontaneous rhythm. In the LB group, all MW indices showed strong correlations between spontaneous rhythm and LBBP. In the non-LB group, GWI (r = 0.685, p < 0.001) and GCW (r = 0.750, p < 0.001) remained strongly correlated, whereas GWE (r = 0.4224, p = 0.01) and GWW (r = 0.395, p = 0.002) showed moderate and weak correlations, respectively. CONCLUSION:Based on our findings, LBBP appears to preserve LV mechanical efficiency to a degree comparable to spontaneous rhythm. Direct engagement of the conduction system, reflected by a nonselective to selective LBBP QRS transition, is associated with greater concordance of MW indices.

Introduction: Palpitations are one of the most common cardiovascular complaints, affecting approximately 6% to 11% of the general population. Since palpitations often occur sporadically and resolve before medical evaluation, diagnosing the underlying rhythm disturbance requires documentation via an electrocardiogram (ECG) recorded during the symptomatic episode. The standard tool for this purpose has long been the 24-h Holter monitor, which has significant limitations, with diagnostic yields as low as 10% to 15%. Objective: This study aims to evaluate the feasibility and diagnostic yield of single-lead ECG recordings from smartwatches in patients presenting with palpitations. Methods: From 1 May 2023 to 1 May 2025, we conducted a prospective, real-world cohort study among consecutive adults referred to the University Hospital of Ferrara-based arrhythmia outpatient clinics for evaluation of palpitations. Eligibility required patients to be ≥21 years of age, report palpitations for which ambulatory documentation was clinically indicated, and already own a compatible smartwatch capable of single-lead ECG. Participants were trained to record a 30-s single-lead ECG at the onset of symptoms. Tracings were transmitted securely and independently reviewed by two blinded electrophysiologists. Results: Fifty-nine patients were enrolled (mean age 52 years, 64% male). Thirty-one patients (52%) transmitted at least one smartwatch-derived electrocardiographic tracing. Seventy-seven smartwatch tracings were received. Of these, 73 (95%) were interpretable; 57 (78%) showed an arrhythmia, whereas 16 (22%) demonstrated normal sinus rhythm. Four recordings (5%) were non-interpretable. From the 57 arrhythmic tracings, 44 distinct arrhythmic diagnoses were identified. Paroxysmal atrial fibrillation (AF) accounted for 16 episodes. Other diagnosed arrhythmias included atrial flutter (n = 6), paroxysmal supraventricular tachycardia (PSVT) (n = 4), premature atrial complexes (PAC) (n = 6), premature ventricular complexes (PVC) (n = 9), inappropriate sinus tachycardia (n = 12), and second-degree atrioventricular (AV) block type I (n = 4). Conclusions: Smartwatch-based ECG monitoring in symptomatic patients is feasible and provides a high diagnostic yield for a broad spectrum of arrhythmias. Unlike large-scale population screening approaches, which generate vast datasets with limited clinical benefit, a symptom-driven strategy applied to carefully selected, educated, and motivated patients proves both clinically valuable and organizationally sustainable. Indeed, the mean number of tracings transmitted per patient was low (1.3), confirming the clinical and operational sustainability of this patient-triggered, real-world approach.

BACKGROUND:Although reports of good clinical outcomes after avoiding defibrillation testing (DFT) during subcutaneous implantable cardioverter defibrillator (S-ICD) implantation have increased over recent years, current guidelines still recommend performing DFT at the time of implant. OBJECTIVE:We aimed to identify predictors of conversion failure in a real-world S-ICD population and assess whether PRAETORIAN score performance is improved by additional clinical variables. METHODS:We analyzed 1063 patients from the international subcutaneous implantable cardioverter defibrillator (iSUSI) registry with available imaging and complete follow-up. The primary endpoint was a composite of DFT failure and ineffective appropriate shocks during follow-up. PRAETORIAN score and individual components were assessed, and receiver operating characteristic curve analysis with DeLong's test was used to evaluate model performance. RESULTS:Patients were classified into low (76.6%), intermediate (16.3%), and high-risk (7.2%) PRAETORIAN score categories. Among 748 patients who underwent DFT, 64 (8.6%) experienced DFT failure; 17 ineffective shocks occurred during follow-up. Primary outcome occurred in 4.5% of low, 6.7% of intermediate-, and 16.8% of high-risk patients. PRAETORIAN score step 1, anterior generator position at PRAETORIAN score step 2 (odds ratio 2.3 [1.2-4.2], P = .006), high body mass index (BMI) and post-shock impedance, independently predicted conversion failure. Overall PRAETORIAN score (area under the curve [AUC] 0.71) outperformed individual steps (step 1-3 AUCs: 0.68-0.70; P > .05 for all comparisons). A multivariable model combining PRAETORIAN score, BMI, and impedance significantly improved predictive accuracy (AUC 0.78 vs 0.71; P = .0078). CONCLUSION:PRAETORIAN score, BMI, and impedance are independent predictors of defibrillation failure. Their combined use may improve risk stratification and may help guide clinical decision-making, especially when DFT is omitted.

BackgroundArrhythmogenic cardiomyopathy (ACM) and Brugada syndrome (BrS) are inherited arrhythmogenic disorders historically defined by their predisposition to ventricular arrhythmias and sudden cardiac death (SCD). Accumulating evidence indicates that both conditions also involve the atrial myocardium and are associated with a high prevalence of supraventricular tachyarrhythmias (SVT). A clearer understanding of their mechanisms and clinical impact is essential to optimize risk stratification and management.MethodsA systematic review was conducted in accordance with the PRISMA 2020 statement. PubMed and the Cochrane Library were searched up to December 2025 for studies reporting atrial fibrillation (AF), atrial flutter (AFL), atrioventricular nodal re-entrant tachycardia (AVNRT), or atrioventricular re-entrant tachycardia (AVRT) in patients with ACM or BrS. Of 487 records identified, 486 were screened after removal of one duplicate, and 30 studies met the inclusion criteria. Data on atrial substrate, SVT prevalence, mechanisms, and clinical outcomes were extracted.ResultsSVT were consistently more frequent in both ACM and BrS than in age-matched general populations. AF was the most common arrhythmia, often arising at a young age and in structurally normal atria. Across studies, SVT were linked to inappropriate implantable cardioverter-defibrillator (ICD) shocks, heart failure progression, recurrence of ventricular arrhythmias, and an elevated thromboembolic risk that was frequently underestimated by the CHA₂DS₂-VASc score.ConclusionsSVT represent a clinically relevant manifestation of ACM and BrS and carry prognostic implications for arrhythmic monitoring, ICD programming, and thromboembolic risk assessment. Prospective studies are needed to refine risk-stratification tools and to clarify the mechanistic overlap between these inherited arrhythmogenic syndromes.

BACKGROUND:Whether sodium-glucose cotransporter 2 inhibitors (SGLT2i) may reduce the risk of developing new-onset left bundle branch block (LBBB) in patients with heart failure with preserved ejection fraction (HFpEF) remains unknown. We investigate the association between SGLT2i use and incident LBBB in patients with HFpEF. METHODS:We conducted a cohort study using a prospectively database of patients with HFpEF. Patients receiving SGLT2i were propensity score-matched 1:1 with historical controls not receiving SGLT2i. The primary endpoint was new-onset LBBB, over a median 24-month follow-up. Cox proportional hazards models and Fine-Gray competing risk analyses were used to assess the association. Pre-specified subgroup analyses evaluated potential effect modification. RESULTS:A total of 254 patients were included after matching (mean age 73 years, 62% female; 127 SGLT2i, 127 controls). Over a median follow-up of 24 month [interquartile range 22-26 months], new-onset LBBB occurred in 6 of 127 patients (4.7%) treated with SGLT2i versus 15 of 127 patients (11.8%) in the control group, corresponding to a hazard ratio (HR) of 0.41 (95% CI: 0.18-0.61, p < 0.001), which remained significant in competing risk analysis for all-cause of death (sHR 0.40; 95% CI 0.18-0.92; p = 0.01). The association was consistent across most subgroups, with no significant interactions. In patients with baseline QRS ≥110 ms and in those without diabetes, the effect did not reach statistical significance, although point estimates were directionally similar. CONCLUSIONS:In HFpEF, SGLT2i use reduced incident LBBB risk over two years, consistent across subgroups, suggesting a role in preserving conduction integrity and preventing electrical dyssynchrony progression.

PURPOSE:Atrial fibrillation (AF) is highly prevalent in patients with transfusion-dependent beta-thalassemia (TDT). Speckle tracking echocardiography (STE) provides detailed information about left ventricular (LV) and atrial function, however its role in TDT patients with AF has not been completely investigated. This study aimed to assess differences in cardiac mechanical parameters between thalassemia patients with and without history of AF. METHODS AND RESULTS:223 TDT patients in sinus rhythm were enrolled and, among them, 26 (11%) had history of AF. A complete STE analysis with the evaluation of global longitudinal strain (GLS), peak atrial longitudinal strain (PALS) and myocardial work (MW) indices were performed. The primary endpoint was the difference in STE parameters. The secondary endpoint was the prevalence of cardiac mechanical dysfunction. Patients with history of AF showed significantly lower values of GLS (19% vs 21%, p = 0.01) and PALS (24% vs 35%, p < 0.001) compared to those without AF. AF patients showed higher prevalence of both ventricular and atrial mechanical dysfunction (respectively 27% vs 12%, p = 0.03 and 42% vs 11%, p < 0.001). PALS showed high discriminative ability (AUC 0.76, 95% CI 0.66-0.85) with an optimal cut-off value of 25.9% to detect those with history of AF. CONCLUSIONS:Among TDT patients, those with history of AF showed lower values of GLS and PALS. Both LV and atrial mechanical dysfunction were significantly prevalent in patients with history of AF and PALS showed high diagnostic accuracy for the detection of AF. CLINICAL TRIAL REGISTRATION:ClinicalTrials.gov id NCT05508932.

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.

Atrial fibrillation (AF) and heart failure (HF) frequently coexist and mutually worsen prognosis, creating a complex clinical scenario in which treatment decisions are increasingly imaging driven. Catheter ablation has emerged as a pivotal rhythm control strategy in selected patients with HF, but careful phenotyping of the atrial and ventricular substrate is essential to balance potential benefits against procedural risk and the likelihood of durable sinus rhythm. In this narrative review, we summarize the role of multimodality imaging across the entire AF care pathway in patients with HF, from candidate selection to intraprocedural guidance and post-ablation follow-up. Ultrasound imaging remains the cornerstone of pre-procedural assessment. Cardiac computed tomography (CCT) refines anatomical characterization of the left atrium, pulmonary veins, and left atrial appendage. Cardiovascular magnetic resonance (CMR) offers comprehensive tissue characterization of atrial and ventricular fibrosis, allowing distinction between atrial primary and atrial secondary AF phenotypes and informing expectations of reverse remodelling. During ablation, intracardiac echocardiography and transesophageal echocardiography optimize transseptal access, catheter navigation, and complication monitoring, and they are particularly relevant with contemporary Pulsed Field Ablation systems. In follow-up, echocardiography, CCT, and CMR are pivotal for quantifying structural reverse remodelling and detecting rare but life-threatening complications such as atrio esophageal fistula and pulmonary vein stenosis. An integrated, multimodality, substrate-based imaging strategy is therefore crucial to personalize rhythm versus rate control decisions and to guide safe, effective ablation in patients with AF and HF.

BACKGROUND:A T2* ≤20 ms in cardiovascular magnetic resonance (CMR) sequences suggests the presence of iron overload cardiomyopathy in patients with transfusion-dependent β-thalassemia (TDT). However, there is still a gap in evidence regarding the independent role of T1 mapping in identifying early myocardial dysfunction. The aim of this study is to investigate the role of T1 mapping in identifying early cardiac mechanical dysfunction in TDT patients with normal T2* values. METHODS:About 154 consecutive TDT patients with T2* >20 ms were enrolled and stratified by reduced (≤955 ms) or normal (>955 ms) T1 mapping values. CMR T1 mapping and speckle tracking echocardiography (STE) indices were evaluated. The primary endpoint was the correlation between T1 mapping and STE indices. The secondary endpoint was the prevalence of cardiac mechanical dysfunction between patients with reduced or normal T1 mapping. RESULT:T1 mapping showed statistically significant correlations with global longitudinal strain (GLS, r = -0.19, p = 0.01), global work index (GWI, r = 0.15, p = 0.04), global constructive work (GCW, r = 0.18, p = 0.02), and peak atrial longitudinal strain (PALS, r = 0.2, p<0.01). The prevalence of cardiac mechanical dysfunction was low, without any difference between patients with reduced or normal T1 mapping. CONCLUSIONS:In TDT patients with normal T2*, T1 mapping demonstrated a weak but significant correlation with echocardiographic indices of cardiac mechanics. The prevalence of cardiac mechanical dysfunction was low without any difference between those with reduced or normal T1 mapping.