Objectives: This review aims to systematically evaluate the clinical outcomes of left ventricle-only fusion pacing (LV-only fCRTp) and identify evidence-based selection criteria that may optimize patient response and long-term therapeutic benefit. Background: Cardiac resynchronization therapy (CRT) is traditionally associated with biventricular pacing (BiVp). However, approximately 20–40% of patients seem to remain non-responders to this therapy. LV-only fCRTp offers a more physiological alternative by combining left ventricular epicardial pacing with the intrinsic ventricular activation wavefront. Beyond optimization strategies, the observed variability in response highlights the need for better patient selection in order to fully unlock its therapeutic potential. Methods: A systematic literature search was conducted in PubMed and Cochrane Library for original articles published up to April 2025, following PRISMA 2020 guidelines. The search focused on LV-only fCRTp performed either through standard RA/LV/RV biventricular devices or RA/LV dual-chamber systems. Results: Twenty-seven studies met the inclusion criteria. Among these, 17 studies obtained LV-only fCRTp using biventricular devices, and 10 were considered true LV-only fCRTp using RA/LV dual-chamber devices. Standard and specific selection criteria were used to qualify patients for LV-only fCRTp. Preserved atrioventricular conduction, ischemic cardiomyopathy, arrhythmic risk stratification, and the management of supraventricular arrhythmias were common overlapping parameters among studies with high variability, highlighting their potential role in response. RA/LV devices yielded consistent clinical benefits and low complication rates, particularly in nonischemic patients with stable AV conduction and low arrhythmic risk, while having a lower financial burden. Conclusions: Beyond guideline recommendations for CRT, this review identifies supplementary selection criteria that could further influence the effectiveness and stability of fusion pacing.

Background: NT-proBNP levels with a wide range at admission play both a diagnostic and a prognostic role in patients with HF. The differences regarding the clinical profiles and demography in decompensated HF patients according to NT-proBNP levels at admission are not clear. Methods: This study aimed to analyze and compare clinical profiles and demographics in patients hospitalized for decompensated heart failure according to levels of NT-proBNP at admission. The study included 302 patients hospitalized for decompensated HF who were divided into three groups based on admission NT-proBNP levels: group A (n = 46, with NT-proBNP level < 3000 pg/mL), group B (n = 130, NT-proBNP level between 3000–10,000 pg/mL), and group C (n = 126, NT-proBNP level > 10,000 pg/mL). Results: Patients hospitalized with decompensated HF and very high levels of NTproBNP, above 10,000 pg/mL at admission, are older, have a lower LVEF, higher NYHA class, more renal dysfunction, and longer hospital stay, resulting in a more severe clinical profile. Conclusions: The presence of very high levels of NT-proBNP may identify a category of patients with a more severe prognosis that requires more aggressive management and closer follow-up.

Background/Objectives: Cardiac resynchronization therapy (CRT) with fusion pacing (“LV only”), also known as fusion-CRT (f-CRT), represents a feasible alternative to cardiac resynchronization therapy (CRT) with biventricular pacing (BiVP), not only in cases of BiVP failure, but also as a primary therapy option due to its potential benefits over traditional CRT. Fusion pacing may be particularly beneficial in selected patients and understanding the structural and functional differences between responders could guide future optimization strategies. This study provides a descriptive comparison between super-responders (SRs) and non-super-responders (NSRs) undergoing fusion-CRT. Methods: Patients with RA/LV-only pacing systems or biventricular CRT systems operating predominantly in LV-only pacing mode due to intrinsic RV conduction were included. A follow-up protocol was conducted for all patients at 6 months and then annually. Data from the most recent follow-up were used for statistical analysis. Super-responders (SRs) were those with substantial reverse remodeling, quantified by a ≥30% reduction in LVESV and a stable LVEF of ≥45% at follow-up. Although SRs were defined based on these reverse remodeling criteria, separate analyses of additional echocardiographic parameters (e.g., left atrial dimensions) were performed to independently assess the broader impact of fusion-CRT on cardiac structure and function. Results: Among 71 patients, 55 were non-super-responders (NSRs) and 16 were super-responders (SRs), with a mean follow-up of 43.2 months. SRs were predominantly female and had smaller left ventricular (LV) dimensions: LVEDd (6.30 cm vs. 6.80 cm, p = 0.02), LVEDV (185 mL vs. 240 mL, p = 0.03), LVESV (132.5 mL vs. 175 mL, p = 0.03), and a higher LVEF (p = 0.03). The follow-up LVEF was positively correlated with changes in LVESV (ρ = 0.557, p < 0.001), but not with NYHA class changes (ρ = 0.184, p = 0.125). Larger baseline LV and left atrial (LA) volumes were associated with a reduced follow-up LVEF (LVESV: ρ = −0.426, p < 0.001; LVEDV: ρ = −0.394, p < 0.001; LAv: ρ = −0.374, p = 0.001). Both groups showed improvement in the NYHA class (p < 0.001, p = 0.007). MR improved significantly in SRs (p = 0.02) and worsened slightly in NSRs (p = 0.13), while TR worsened significantly in the NSRs group (p = 0.03). Conclusions: Our findings highlight key differences in clinical and echocardiographic parameters between SRs and NSRs following fusion-CRT. These observations may contribute to a better understanding of response patterns and inform future prospective studies aiming to optimize patient selection and timing of therapy.

INPLASY202550034 Comorbidities and long-term mortality after cardiac resynchronization therapy: a scoping review Keywords: cardiac resynchronization therapy; biventricular pacemaker; CRT; CRT-D; CR…

The saga of antiarrhythmic drug (AAD) therapy reflects a field shaped by empiricism and burdened by challenges related to safety. The Singh–Vaughan–Williams classification was a timely necessity that eventually slowed pharmacological innovation by prioritizing electrophysiologic properties over arrhythmogenic mechanisms. The present, limited pharmacological armamentarium demands efforts to reassess legacy antiarrhythmics, repurpose non-antiarrhythmic agents as upstream or downstream therapy, and develop novel compounds. Flecainide, propafenone, and dronedarone have demonstrated their reliable efficacy and safety, even in patients with structural heart disease, which should allow clinicians to reduce their reliance on amiodarone. Previous concerns regarding the proarrhythmic risk of dofetilide and ibutilide are currently managed through careful patient selection and adequate QT interval monitoring. Novel targeted AADs are advancing through the development pipeline, of which etripamil and landiolol have already been approved. Other emerging drugs, such as SK channel blockers (AP30663 and AP31969), RyR2 blockers, CaMKII inhibitors, and TASK-1 blockers (doxapram), are aligned with the new paradigm of atrial fibrillation that focuses on triggers and re-entry. Once triggered, arrhythmias are perpetuated by the underlying substrate, which could be directly targeted by antifibrotic therapy. Developing concepts such as atrial cardiomyopathy allows clinicians to characterize substrate objectively, in order to assess disease severity and individualize antiarrhythmic treatment. The future of antiarrhythmic therapy will be reshaped by artificial intelligence and digital twinning, which allow precise phenotyping and a tailored approach based on individual patient profiles, complemented by rhythm monitoring through wearables.