Heart rhythm最新文献

Background: Cardiac magnetic resonance imaging (MRI) aids the identification of the critical substrate in scar-dependent ventricular tachycardia (VT). Anatomic assessment (AA) of MRI images detects channels that may sustain VT and are viable targets for ablation. Heart digital twins (DTs) combine anatomic data with functional assessment to identify the VT isthmus.

Objective: This study aimed to assess the additional benefit of combining functional data with anatomy using a DT compared with purely AA in identifying the critical substrate in 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 personalized heart geometry and functional properties were generated and tested for VT inducibility, and optimum ablation lesion sites were 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. The total area predicted for ablation was similar between AA and DT (9.94 cm² [±9.46 cm²] vs 9.84 cm² [±3.23 cm²]; P = .96). The sensitivity for detection of abnormal electrograms was greater with DT than AA (51.4% [±17.6%] vs 25.3% [±25.4%]; P = .002). The sensitivity of detection of deceleration zones, mid-diastolic potentials, and sites of VT termination with ablation was higher with DT than AA, with DT correctly identifying 13 of 16 mid-diastolic potentials (81.3%) compared with 8 of 16 by AA (50.0%).

Conclusion: The addition of functional data improves detection of the critical substrate above purely AA in scar-dependent VT. DTs are a potentially useful aid in VT ablation.

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

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

Methods: A systematic search was conducted in 4 databases for studies comparing OAC discontinuation with maintenance in patients with AF postablation. We pooled odds ratios (ORs) for binary outcomes with a random effects model and performed sensitivity analyses using hazard ratios and subgroups based on CHA₂DS₂-VASc scores and sinus rhythm status.

Results: 32 studies were included, comprising 271,808 patients, with 88,164 (32.4%) discontinuing OAC use after ablation. The primary analysis showed no significant differences in TE incidence (OR 0.90; 95% confidence interval 0.68-1.20; P = .47) or mortality (OR 0.85; 95% confidence interval 0.67-1.08; P = .19). However, OAC discontinuation was significantly associated with reduced major bleeding events (OR 0.35; P < .01). For patients with a CHA₂DS₂-VASc score >2, discontinuing OAC significantly increased TE risk. For patients with CHA₂DS₂-VASc scores 0-2 and those sustaining sinus rhythm, the results were consistent with the overall analysis.

Conclusion: Discontinuation of OACs in patients with AF postablation did not significantly affect the overall TE incidence but was associated with a notable reduction in major bleeding events. However, there was a significant increase in TE risk in patients with a CHA₂DS₂-VASc score >2 upon discontinuation.

Background: Early recurrence of atrial tachyarrhythmias (ERAT) is common after pulmonary vein isolation (PVI) and is traditionally attributed to transient post-procedural inflammation. With the introduction of pulsed field ablation (PFA), the incidence and prognostic significance of ERAT compared with thermal ablation remains unknown.

Objective: The study aimed to compare the incidence of ERAT during the blanking period in patients undergoing PFA versus radiofrequency (RF) ablation for atrial fibrillation (AF).

Methods: We prospectively enrolled patients undergoing first-time PVI between 2022 and 2025 at our institution. Propensity score matching was performed to address baseline imbalances and group size differences between RF and PFA PVI. The incidence of ERAT and its association with 9-month arrhythmia recurrence, defined as late recurrence of atrial tachyarrhythmias (LRAT), were analyzed.

Results: A total of 962 patients were included (420 RF, 542 PFA). Patients with ERAT were more likely to be older, have persistent AF, higher CHA₂DS₂-VASc scores, larger atria, reduced ejection fraction, and no prior antiarrhythmic drug use. After multivariable adjustment, PFA was independently associated with a lower risk of ERAT compared with RF (hazard ratio [HR] 0.61; 95% confidence interval 0.42-0.88). ERAT was strongly associated with LRAT, with a 3-4-fold higher risk of atrial arrhythmias at 9 months (early ERAT: HR 3.78, P < .001; late ERAT: HR 4.10, P = .001), regardless of ablation modality.

Conclusion: PFA is associated with a significantly lower risk of ERAT compared with RF ablation. The occurrence of ERAT, irrespective of energy source, predicts a substantially higher risk of LRAT.

Background: The autonomic effects of pulsed-field ablation (PFA) remain incompletely defined. Previous work has relied on heart rate variability (HRV), which cannot differentiate sympathetic from vagal activity. We used deceleration capacity (DC) and acceleration capacity (AC)-valid vagal/sympathetic activity measures-to evaluate autonomic changes before and after PFA for paroxysmal atrial fibrillation (PAF).

Objective: The study aimed to characterize peri-PFA changes in DC/AC in patients with PAF.

Methods: This prospective study included 45 consecutive patients with PAF who experienced PFA. DC/AC and HRV were performed at baseline, immediately after ablation, and at 3-month follow-up. The relationship between HRV and DC/AC was assessed using Pearson correlation. Receiver operating characteristic analyses were used to evaluate the predictive value of DC/AC for atrial fibrillation (AF) recurrence. Kaplan-Meier analysis assessed freedom from AF recurrence over 12 months in relation to autonomic indices.

Results: Pulmonary vein isolation was successful in all patients; 91.1% exhibited intraprocedural vagal responses. DC and |AC| decreased immediately after PFA and partially recovered at 3 months (overall P < .05 for both). Most HRV parameters had weak correlations with DC/AC (Pearson r = 0.08-0.67). At 12 months, the drug-free atrial tachycardia-free rate was 75.56%. Preablation DC/AC (area under the curve 0.63/0.64) and changes in DC/AC (area under the curve 0.68/0.67) were able to predict AF recurrence. Patients with lower preablation |AC| and smaller ΔDC/ΔAC had significantly higher AF recurrence rates (log-rank P < .05).

Conclusion: Our evaluation via DC/AC revealed significant alterations in autonomic activity after PFA. Furthermore, DC/AC and their trajectories demonstrated moderate predictive value for AF recurrence, underscoring the need to reconsider the impact of PFA on cardiac autonomic innervation.

Background: Antitachycardia pacing (ATP) can prevent defibrillator shocks and associated adverse outcomes. Opportunities to enhance ATP performance exist, particularly for rapid monomorphic ventricular tachycardia (MVT). Intrinsic ATP (iATP) is the first closed-loop algorithm that designs and auto-adjusts ATP therapy in real time.

Objective: This study aimed to evaluate iATP performance in a large, real-world cohort.

Methods: This global, prospective, observational study enrolled patients with an iATP-enabled implantable cardioverter-defibrillator or cardiac resynchronization therapy-defibrillator device. The primary objective, to demonstrate iATP could effectively terminate >60% of MVT episodes in the fast ventricular tachycardia (VT) zone, was analyzed using the generalized estimating equations (GEE) method. Additional analyses included overall effectiveness and the rate of MVT acceleration resulting in shock. A post hoc analysis used GEE models to compare iATP data with standard ATP from a retrospective cohort.

Results: In total, 1875 enrolled patients were followed for a total of 3200 patient-years, yielding 2575 iATP-treated MVT episodes. Of 265 iATP-treated episodes in the fast VT zone (73 patients), the GEE-estimated success rate was 89.7% (95% confidence interval [CI] 83.6-93.7), exceeding the primary objective. The GEE-estimated rate of iATP-associated MVT acceleration resulting in shock was 2.3%. Compared with standard ATP, iATP almost doubled the odds of VT termination (adjusted odds ratio 1.87; 95% CI 1.32-2.66; P = .0005) and halved the odds of acceleration resulting in shock (adjusted odds ratio 0.43; 95% CI 0.25-0.74; P = .0026).

Conclusion: In routine practice, iATP was highly effective and safe across all VT rates. Although exploratory, iATP had overall superior termination rates and a lower chance of acceleration resulting in shock than standard ATP.

Atrial electrical remodeling spans molecular, electrical, and structural alterations that shorten refractoriness, facilitate reentry, and ultimately create the atrial substrate underlying atrial fibrillation (AF). These changes include ion channel dysfunction, calcium-handling abnormalities, oxidative injury, and deranged proteostasis that are tightly intertwined with atrial fibrosis and cardiomyopathy. High-density mapping and advanced imaging now allow in vivo staging of this substrate: left atrial low-voltage areas and functional conduction phenomena identify regions of fibrosis and conduction slowing that are associated with postablation recurrence, although the benefit of low-voltage area-targeted substrate ablation remains uncertain. Building on this pathophysiological framework, this review integrates experimental and clinical evidence to guide decision making in AF therapy, emphasizing early rhythm-control strategies and careful substrate characterization in sinus rhythm. Pulmonary vein (PV) isolation is presented as the cornerstone of ablation, whereas adjunctive substrate-oriented strategies, including low-voltage modification, hybrid surgical-catheter approaches, and vein of Marshall-based techniques, are discussed as investigational options for selected high-risk patients. Finally, the review contrasts PV- and non-PV-dependent forms of AF and appraises emerging artificial intelligence-guided electrogram interpretation within a mechanism-driven framework for personalized management of atrial electrical remodeling.