Heart rhythm最新文献

Background: Creating durable linear lesions in the left atrium (LA) is the prerequisite for successful catheter ablation of peri-mitral flutter.

Objective: Using photon-counting computer tomography (PCCT), we compared patterns of myocardial thickness (MT), epicardial adipose tissue (EAT) and length of commonly used LA lines to determine the most favorable line profile for catheter ablation.

Methods: 198 patients were prospectively included. PCCT of the LA was performed in all patients. After semiautomated 3D-segmentation of PCCT data, five ablation lines were simulated using specialized imaging software. These included an anteroseptal (AS), anteromedial (AM) and anterolateral line (AL) as well as superior (MIS) and inferior mitral isthmus line (MII). MT, EAT and line length were analyzed.

Results: The data set included 115763 data points along 990 simulated lines in 198 patients. Line length was shortest in MII, longest in AM. AS showed the lowest average MT values. MT interpatient variability was greatest along the MIS. EAT was distributed inhomogenously at the anterior wall with thicker layers in medial and especially lateral aspects and highest EAT levels along the AL line. When combining MT, EAT and line length in a weighted score, AS and MII lines demonstrated the most favorable profiles for catheter ablation.

Conclusions: PCCT/3D-segmentation as a tool to visualize MT and EAT is very helpful to determine the most favorable line for catheter ablation of peri-mitral flutter. In a weighted score incorporating MT, EAT and line length, AS and MII lines showed promising profiles for the creation of durable linear lesions.

Background: Left septal myocardial pacing (LVSP) is present in the areas where left bundle branch (LBB) capture is not feasible with high pacing output (general LVSP), or in LV subendocardial locations, where it transits from LBBP during the decremental output pacing (LV subendocardial pacing - LVSeP).

Objective: To compare electrical ventricular synchrony and acute hemodynamic response between LBBP and LVSeP.

Methods: Consecutive CRT patients with transition from nsLBBP to LVSeP during decremental output pacing were enrolled. Ventricular dyssynchrony was assessed using UHF-ECG. The acute hemodynamic response was assessed using a high-precision hemodynamic protocol with invasive measurements of systolic blood pressure. An invasive intracardiac mapping of the left ventricular septum was performed during both captures.

Results: The study included 21 patients. LVSeP and LBBP had the same QRSd (159 ± 18 ms vs. 151 ± 15 ms, p = 0.26), but LVSeP had a longer V6RWPT (98 ± 13 ms vs. 79 ± 12 ms, p < 0.001) and post-pacing isoelectric interval (48 ± 9 vs. 39 ± 9, p < 0.001). However, no significant difference was observed in LV synchrony (14 ± 5 ms vs. 16 ± 6 ms, p = 0.21) and average systolic blood pressure (121 ± 18 mmHg vs. 122 ± 17 mmHg, p = 0.78). Intracardiac mapping of one patient showed that both LVSeP and LBBP activated the LV septum at the recording site via the His-Purkinje system.

Conclusion: In CRT candidates, LVSeP preserved LV synchrony and acute hemodynamic response at the same level as direct LBBP. Further clinical research is warranted to better understand the differences between various types of left septal pacing.

Background: Adult congenital heart disease (ACHD) patients often develop heart failure (HF). Cardiac resynchronization therapy (CRT) may provide benefit, but evidence is limited to observational studies and guidelines are extrapolated from acquired HF.

Objectives: To systematically evaluate the effects of CRT in ACHD, including both biventricular (BiV) and conduction system pacing (CSP) strategies, on electrocardiographic, functional, and clinical outcomes.

Methods: We conducted a systematic review and meta-analysis following PRISMA guidelines (PROSPERO CRD420251036152). PubMed, Embase, Web of Science, CINAHL, and Cochrane were searched to February 2025. Primary outcomes were changes in QRS duration, systemic ventricular function (SVF), and New York Heart Association (NYHA) class; secondary outcomes were HF hospitalizations and all-cause mortality.

Results: Twenty-five studies (n=796; 723 BiV, 73 CSP) were included. CRT was associated with significant QRS duration reduction (-23.1 ms, 95% CI -31.6 to -14.7), SVF improvement (+7.8%, 5.9-9.6), and NYHA class reduction (-0.9, -1.2 to -0.5). Benefits extended to systemic right ventricle (sRV) patients (QRS -27.7 ms, SVF +8.5%, NYHA -1.0). Pooled incidence rates of HF hospitalization and mortality were 4.3 and 3.2 per 100 patient-years, respectively. Early data suggest CSP achieves comparable QRS narrowing to BiV, though long-term outcomes remain scarce.

Conclusion: CRT in ACHD is associated with significant improvements in electrocardiographic, functional, and clinical outcomes, including sRV patients. While most evidence pertains to BiV, early reports on CSP are encouraging. Prospective, phenotype-specific studies with standardized outcomes are needed to optimize patient selection and pacing strategies.

Background: Atrial fibrillation (AF) is the most common arrhythmia among the elderly and a major contributor to morbidity and mortality. Inflammation plays a central role in AF pathogenesis, and aging is a key independent risk factor. Cellular senescence is a hallmark of aging and contributes to age-related disease through the senescence-associated secretory phenotype (SASP), characterized by pro-inflammatory and pro-fibrotic factors.

Objective: To determine whether senescent atrial cells contribute to age-related AF risk and whether senolytic therapy can mitigate this phenotype.

Methods: Young (≤1 year) and aged (≥4 years) New Zealand White rabbits were evaluated using optical mapping, patch-clamp electrophysiology, and histological and molecular analyses. Senescence markers were assessed by SA-β-Gal staining, immunofluorescence, and RNA-seq. Human atrial specimens from patients with and without AF were examined to assess translational relevance. Aged rabbits received the senolytic compound fisetin to evaluate its effects on atrial senescence and arrhythmia susceptibility.

Results: Aged rabbits displayed electrophysiological heterogeneity, prolonged action potentials, and increased AF inducibility, recapitulating clinical features of elderly human atria. Atrial tissue from aged rabbits and patients with AF showed an increase in senescent myocytes and myofibroblasts with upregulation of inflammatory SASP genes. SASP factor expression correlated with left atrial diameter in human samples, an AF risk factor. Short-term fisetin treatment eliminated most senescent atrial cells, reduced inducible AF, and decreased reentry activity without impairing atrial function.

Conclusions: Senescent atrial cells promote a pro-inflammatory, pro-arrhythmic substrate predisposing to AF. Senolytic therapy with fisetin alleviates this phenotype, suggesting a potential strategy to prevent age-related AF.

Background: Frailty is common among patients with heart failure and is associated with non-arrhythmic morbidity and mortality. Whether frailty assessment can be used to improve risk stratification among patients undergoing primary prevention implantable cardioverter-defibrillator (ICD) placement is unknown.

Objective: This study examined the association between frailty and death without ICD therapy following ICD implantation among patients with heart failure.

Methods: We used data from the Biotronik CERTITUDE Registry linked to Medicare claims to identify adults aged ≥66 years with heart failure who underwent primary prevention ICD implantation between 1/1/2015 and 12/22/2022. Frailty was assessed using the validated Claims-Based Frailty Index (CFI) and stratified into robust (CFI <0.15), pre-frail (CFI 0.15-0.25), and frail (CFI ≥0.25) groups.

Results: Among 1060 adults with heart failure who underwent primary prevention ICD implantation, 12.1% (128) were identified as frail. The primary outcome of death without ICD therapy for up to 5-years increased stepwise across frailty groups (16.5% in robust, 26.3% in pre-frail, 45.3% in frail; p<0.001), with a similar pattern observed for all-cause mortality (26.3%, 37.3%, 55.5%, respectively; p<0.001). After adjusting for age, sex, and comorbidities, frailty remained associated with death without ICD therapy (frail vs. robust; HR 1.92, 95% CI 1.12-3.29) and mortality (frail vs. robust; HR 1.66, 95% CI 1.07-2.58). The frailty threshold (CFI=0.20) identified the point where predicted 5-year risk of death without ICD therapy exceeded risk of ICD therapy.

Conclusion: Frailty is associated with higher risks of death without ICD therapy and all-cause mortality among patients undergoing primary prevention ICD.

Background: Cardiac MRI aids identification of critical substrate in scar-dependent VT. Anatomical assessment (AA) of MRI images detects channels which may sustain VT and are viable targets for ablation. Heart digital twins (DT) combine anatomical data with functional assessment to identify the VT isthmus.

Objective: To assess the additional benefit of combining functional data with anatomy using a DT compared to purely anatomical assessment in identifying critical substrate in ventricular tachycardia (VT).

Methods: 18 patients with scar-dependent VT planned for catheter ablation underwent contrast-enhanced cardiac MRI. AA to derive conducting channels was performed. Simultaneously, heart DT models combining personalised heart geometry and functional properties were generated and tested for VT inducibility and optimum ablation lesion sites predicted. Patients underwent invasive VT ablation. Detection of scar and critical substrate was compared between AA and DT.

Results: Scar identification was similar between AA and DT. Total area predicted for ablation was similar between AA and DT (9.94cm² [± 9.46cm²] vs 9.84cm² [± 3.23cm²], p = 0.96). Sensitivity for detection of abnormal electrograms was greater with DT compared to AA (51.4% [± 17.6%] versus 25.3% [± 25.4%], p = 0.002). Sensitivity of detection of deceleration zones, mid-diastolic potentials (MDP) and sites of VT termination with ablation was higher with DT than AA, with DT correctly identifying 13/16 (81.3%) of MDP compared to 8/16 by AA (50.0%).

Conclusions: Addition of functional data improves detection of critical substrate above purely anatomical assessment in scar-dependent VT. Digital twins are a potentially useful aid in VT ablation.

Background: Ablation procedures are frequently employed to restore sinus rhythm in atrial fibrillation (AF), given the increased stroke risk associated with AF. The decision to discontinue oral anticoagulation (OAC) therapy post-procedure requires careful consideration of stroke and bleeding risks, especially due to the absence of definitive guidelines.

Objective: This meta-analysis aims to evaluate the implications of OAC discontinuation following catheter ablation for AF, focusing on thromboembolic (TE) and bleeding events.

Methods: A systematic search was conducted in four databases, for studies comparing OAC discontinuation with maintenance in AF patient's post-ablation. We pooled odds ratios (OR) for binary outcomes with random-effects model and performed sensitivity analyses with hazard ratios (HR) and subgroups based on CHA₂DS₂-VASc scores, and patients in sinus rhythm.

Results: Thirty-two studies were included, comprising 271,808 patients, with 88,164 (32.4%) discontinuing OAC. The primary analysis showed no significant differences in TE incidence (OR 0.90; 95% CI: 0.68 to 1.20; p=0.47) or mortality (OR 0.85; 95% CI: 0.67 to 1.08; p=0.19). However, OAC discontinuation was significantly associated with reduced major bleeding events (OR 0.35; p<0.01). For patients with a CHA₂DS₂-VASc score >2, discontinuing OAC significantly increased TE risk. For those with CHA₂DS₂-VASc scores 0-2 and in patients sustaining sinus rhythm, the results were consistent with the overall analysis.

Conclusion: Discontinuation of OACs in AF patient's post-ablation did not significantly affect overall TE incidence but a notable reduction in major bleeding events. However, there was a significant increase in TE risk among patients with CHA₂DS₂-VASc >2 upon discontinuation.