Europace最新文献

Alterations in repolarization gradients and increased heterogeneity are key electrophysiological determinants of ventricular arrhythmogenesis across a variety of aetiologies with and without structural heart disease. High-density repolarization mapping to localize these repolarization abnormalities could improve characterization of the individual arrhythmogenic substrate and inform more targeted ablation. Yet, due to challenges posed by intrinsic features of human cardiac repolarization itself as well as technical and practical limitations, they are not routinely assessed, and traditional substrate mapping techniques remain strictly limited to determining conduction abnormalities. Here, we provide an overview of the mechanistic role of repolarization alterations in ventricular re-entry arrhythmias followed by a description of a clinical workflow that enables high-density repolarization mapping during ventricular tachycardia (VT) ablations using existing clinical tools. We describe step-by-step guidance of how-to set-up and generate repolarization maps illustrating the approach in case examples of structural normal and abnormal hearts. Furthermore, we discuss how repolarization mapping could be combined with existing substrate mapping approaches, including isochronal late activation mapping, to delineate sites of increased re-entry vulnerability, that may represent targets for ablation without the requirement for VT induction. Finally, we review challenges and pitfalls and ongoing controversies in relation to repolarization mapping and discuss the need for future technical and analytical improvements in repolarization mapping to integrate into ventricular substrate mapping strategies. Repolarization mapping remains investigational, and future research efforts need to be focused on prospective trials to establish the additional diagnostic value and its role in clinical ablation procedures.

The co-ordinated electrical activity of ∼2 billion cardiac cells ensures stability of the heartbeat. Indeed, the remarkably low incidence (<1%) of ventricular arrhythmias in the healthy heart is only possible when the electrical event across this syncytium is closely controlled. In contrast, the diseased myocardium is associated with increased electrophysiological heterogeneity, unstable rhythm, and increased incidence of lethal arrhythmias. But what is the link between cellular and tissue level heterogeneity? Recent research has shown the existence of considerable cellular heterogeneity even in the healthy heart, suggesting that cell-to-cell variability in electrical (e.g. action potential duration) and mechanical performance (e.g. twitch amplitude) is a normal property. This observation has been previously unappreciated because the aggregated function in the form of QT-interval and cardiac output varies <1% on a beat-to-beat basis. This article describes the underlying cellular variability that is tolerated-and perhaps needed-by different regions of the heart for normal function and indicates why this variability is not apparent in function at the chamber and organ level. Thus, in contrast to the current dominant view, this article postulates that heterogeneity is normal and potentially endows various functional benefits. This new view of how the component parts of the heart come together to function also suggests novel mechanisms for cardiac pathologies, namely that dysfunction may emerge from changes in the extent and/or nature of heterogeneity. Once understood, restoring normal forms of heterogeneity could be a novel approach to treatment.

Aims: Structural and fibrotic remodelling is a well-known contributor to the atrial fibrillation (AF) substrate. Epicardial adipose tissue (EAT) is increasingly recognized as a contributor through electrical remodelling in the atria. We aimed to assess the association of LA fibrosis and EAT with LA strain and function using cardiac magnetic resonance (CMR) imaging in patients with AF.

Methods and results: LA fibrosis was assessed using late gadolinium enhancement CMR, LA EAT was assessed using the fat-water separation Dixon sequence, and feature tracking was applied to assess global longitudinal strain in its three components [reservoir (GLRS), conduit (GLCdS), and contractile (GLCtS)]. LA emptying fraction and LA volume were measured using the cine sequences. All CMR images were acquired in sinus rhythm. One hundred one AF patients underwent pre-ablation CMR (39% female, average age 62 years). LA fibrosis was negatively associated with the three components of global longitudinal strain (GLRS: R = -0.35, P < 0.001; GLCdS: R = -0.24, P = 0.015; GLCtS: R = -0.2, P = 0.046). Out of the different sections of the LA, fibrosis in the posterior and lateral walls was most negatively correlated with GLRS (R = -0.32, P = 0.001, and R = -0.33, P = 0.001, respectively). LA EAT was negatively correlated with GLCdS (R = -0.453, P < 0.001). LA fibrosis was negatively correlated with LA emptying fraction but LA EAT was not (R = -0.27, P = 0.007, and R = -0.22, P = 0.1, respectively). LA EAT and fibrosis were both positively correlated with LA volume (R = 0.38, P = 0.003, and R = 0.24, P = 0.016, respectively).

Conclusion: LA fibrosis, a major component of the AF substrate, and EAT, an important contributor, are associated with a worsening LA function through strain analysis by CMR.

Aims: Cardiac conduction disorders are common in haemodialysis patients, with a relatively high rate of pacemaker implantations. Pacemaker-related complications, especially lead infections and central venous stenosis, pose significant challenges in this population. This study aims to compare single-chamber leadless pacemaker to single-chamber transvenous pacemakers in terms of survival and related complications in haemodialysis patients.

Methods and results: This retrospective study included adult haemodialysis patients who received a first single-chamber transvenous or leadless pacemaker between January 2017 and December 2020. Data were obtained from the French national REIN registry matched to the national health databases (Système National des Données de Santé). Propensity score matching was used to balance baseline characteristics. Survival and complications were compared between groups by Cox regression and by competitive risk models, respectively. One hundred and seventy-eight patients were included after propensity score matching, with 89 patients in each group. The median follow-up time was 24 (range 7-37) months. Leadless pacemakers were associated with significantly lower all-cause mortality rates compared to transvenous pacemakers [hazard ratio (HR) = 0.68, 95% confidence interval (CI) (0.47-0.99)]. Device-related infections are significantly lower with leadless pacemakers throughout the follow-up period (HR 0.43, 95% CI 0.21-0.86). Leadless pacemaker recipients also required fewer vascular access interventions [odds ratio 0.53, 95% CI (0.33-0.68)] on arteriovenous fistula.

Conclusion: With the limitations of its observational design, this study suggests that leadless pacemakers are associated with a lower rate of complications and better survival as compared with transvenous VVI pacemakers in haemodialysis patients, supporting to consider their preferential use in this population.

Aims: Rotational re-entries and ectopic foci, or 'drivers', are proposed mechanisms for persistent atrial fibrillation (persAF), but driver-based interventions have had mixed success in clinical trials. Selective targeting of drivers with multi-month stability may improve these interventions, but no prior work has investigated whether drivers can be stable on such a long timescale.

Objective: We hypothesized that drivers could recur even several months after initial observation.

Methods and results: We performed serial electrophysiology studies on paced canines (n = 18, 27-35 kg) at 1-, 3-, and 6 months post-initiation of continual persAF. Using a high-density 64-electrode catheter, we captured endocardial electrograms in the left atrium (LA) and right atrium (RA) to determine the presence of drivers at each major anatomical site. We defined drivers that were repeatedly observed across consecutive studies to be recurrent. The mean probability that any driver would recur was 66% (LA: 73%, RA: 41%). We also found evidence of 'multi-recurring' drivers, i.e. those seen in all three studies. Multi-recurring drivers constituted 53% of initially observed drivers with at least one found in 92% of animals, and we found more multi-recurring drivers per animal than predicted by random chance (2.6 ± 1.5 vs. 1.2 ± 1.1, P < 0.001). Driver sites showed more enhancement than non-drivers during late gadolinium enhancement-magnetic resonance imaging (P = 0.04), but we observed no relationship between enhancement and driver recurrence type.

Conclusion: We observed recurring drivers over a 6-month period at fixed locations, confirming our hypothesis. We also found drivers to be associated with fibrosis, implying a structural basis.

Aims: Catheter ablation is an effective treatment method for recurrent ventricular tachycardias (VTs). However, at least in part, procedural and clinical outcomes are limited by challenges in generating an adequate lesion size in the ventricular myocardium. We investigated procedural and clinical outcomes of VT ablation using a novel 'large-footprint' catheter that allows the creation of larger lesions either by radiofrequency (RF) or by pulsed field (PF) energy.

Methods and results: In prospectively collected case series, we describe our initial experience with VT ablation using a lattice-tip, dual-energy catheter (Sphere-9, Medtronic), and a compatible proprietary electroanatomical mapping system (Affera, Medtronic). The study population consisted of 18 patients (aged 55 ± 15 years, one woman, structural heart disease: 94%, ischaemic heart disease: 56%, left ventricular ejection fraction: 34 ± 10%, electrical storm: 22%) with recurrent sustained VTs and ≥1 previously failed endocardial RF ablation with conventional irrigated-tip catheter in 66% of patients. On average, 12 ± 7 RF and 8 ± 9 PF applications were delivered per patient. In three-fourths of patients undergoing percutaneous epicardial ablation, spasms in coronary angiography were observed after PF applications. All resolved after intracoronary administration of nitrates. No acute phrenic nerve palsy was noted. One patient suffered from a stroke that resolved without sequelae. Post-ablation non-inducibility of VT was achieved in 89% of patients. Ventricular-arrhythmia-free survival at three months was 78%.

Conclusion: VT ablation using a dual-energy lattice-tip catheter and a novel electroanatomical mapping system is feasible. It allows rapid mapping and effective substrate modification with good outcomes during short-term follow-up.

Aims: The use of ultrasound (US)-guided venous puncture for cardiac pacing/defibrillation lead placement may minimize the risk of periprocedural complications and radiation exposure. However, none of the published studies have been sufficiently powered to recommend this approach as the standard of care. We compare the safety and efficacy of ultrasound-guided axillary venous puncture (US-AVP) vs. fluoroscopy-guided access for cardiac implantable electronic devices (CIEDs) by performing an individual patient data meta-analysis based on previously published studies.

Methods and results: We conducted a thorough literature search encompassing longitudinal investigations (five randomized and one prospective studies) reporting data on X-ray-guided and US-AVP for CIED procedures. The primary endpoint was to compare the safety of the two techniques. Secondary endpoints included the success rate of each technique, the necessity of switching to alternative methods, the time needed to obtain venous access, X-ray exposure, and the occurrence of periprocedural complications. Six longitudinal eligible studies were identified including 700 patients (mean age 74.9 ± 12.1 years, 68.4% males). The two approaches for venous cannulation showed a similar success rate. The use of an X-ray-guided approach significantly increased the risk of inadvertent arterial punctures (OR: 2.15, 95% CI: 2.10-2.21, P = 0.003), after adjustment for potential confounders. Conversely, a US-AVP approach reduces time to vascular access, radiation exposure, and the number of attempts to vascular access.

Conclusion: The US-AVP enhances safety by reducing radiation exposure and time to vascular access while maintaining a low rate of major complications compared to the X-ray-guided approach.

Clinical trial registration: PROSPERO identifier: CRD42024539623.

Aims: A novel three-dimensional mapping platform combined with a lattice-tip catheter that can toggle between monopolar pulsed field ablation (PFA) and radiofrequency energy delivery was recently launched. So far, the system was predominantly applied in general anaesthesia (GA), not in deep sedation.

Methods and results: Patients with symptomatic paroxysmal or persistent atrial fibrillation (AF) were enrolled, and pulmonary vein isolation (PVI) and ablation of additional linear lesion sets were performed either in GA or in deep sedation. Pulsed field ablation was applied exclusively to perform ipsilateral PVI. A total of 63 patients (35% female, 75% persistent AF, mean age 64 ± 9 years) were included in the analysis with 23 patients treated in GA and 40 patients in deep sedation. Acute efficacy was comparable in both groups with a PVI rate of 100%. Additional 74 lesion sets were performed in the total cohort. Mean procedure and lab occupancy time in the GA and deep sedation group was 96 ± 24 min vs. 100 ± 23 min (P = 0.52) and 165 ± 40 min vs. 131 ± 35 min (P = 0.0008). Mean dose area product was 489 (216;1093) vs. 452 (272;882) cGycm2 in the GA and the deep sedation group (P = 0.82). There was one conversion from deep sedation to GA. There were no map shifts observed in any group. Pericardial tamponade occurred in one patient of the deep sedation group.

Conclusion: The use of a novel ablation platform in conjunction with a lattice-tip catheter in deep sedation is feasible, effective, and associated with significantly shorter lab occupancy time when compared with GA.

Aims: The CHA2DS2VASc score is recommended for stroke risk stratification in patients with atrial fibrillation (AF). This score assigns one extra point to female sex based on evidence from the early 2000s, suggesting higher thromboembolic risk in women. This incremental risk of thromboembolism in women has decreased over time between 2007 and 2018, becoming non-significant in recent years. The objective of this study was to assess the impact of removing the sex category (Sc) from the CHA2DS2VASc score, thus validating a non-sex CHA2DS2VASc (i.e. CHA2DS2VA) score.

Methods and results: We analysed UK primary and secondary care data comprising 195 719 patients with AF followed between 1998 and 2016 (mean age: 75.9 ± 12.3 years; 49.2% women). Among 126 428 non-anticoagulated patients, we compared the CHA2DS2VASc vs. CHA2DS2VA scores every calendar year. Throughout 413 007 patient-years, a total of 8742 events of ischaemic stroke or systemic embolism were recorded. Sex differences in thromboembolic risk were not observed in the lower-risk population, but higher stroke rates were consistently seen in female patients in the higher-risk category (i.e. CHA2DS2VA ≥2). C-statistics for both CHA2DS2VA and CHA2DS2VASc scores were similar over the years (ranging from 0.62 to 0.71). With CHA2DS2VA, no relevant differences were observed in integrated discrimination improvement, and net reclassification improvement (NRI) resulted in improved reclassification (11%) in lower thromboembolic risk groups. The NRI suggested misclassification in higher thromboembolic risk patients (-7%), but this did not affect their indication for anticoagulation (i.e. patients retained their high-risk status).

Conclusion: Removing Sc from the CHA2DS2VASc score does not affect its ability to discriminate thromboembolic events in the population with AF. The use of CHA2DS2VA may simplify initial decision-making for thromboprophylaxis.

Aims: Atrial fibrillation (AF) patients frequently require active rhythm control therapy to maintain sinus rhythm and reduce symptom burden. Our study assessed whether antiarrhythmic therapies (AATs) are used disproportionately between men and women after new-onset AF.

Methods and results: The nationwide Finnish anticoagulation in AF registry-based linkage study covers all patients with new-onset AF in Finland during 2007-2018. Study outcomes included initiation of AATs in the form of antiarrhythmic drugs (AADs), cardioversion, or catheter ablation. The study population constituted of 229 565 patients (50% females). Women were older than men (76.6 ± 11.8 vs. 68.9 ± 13.4 years) and had higher prevalence of hypertension or hyperthyroidism, but lower prevalence of vascular disease, diabetes, renal disease, and cardiomyopathies than men. Overall, 17.6% of women and 25.1% of men were treated with any AAT. Women were treated with AADs more often than men in all age groups [adjusted subdistribution hazard ratio (aSHR) 1.223, 95% confidence interval (CI) 1.187-1.261]. Cardioversions were also performed less often on women than on men aged <65 years (aSHR 0.722, 95% CI 0.695-0.749), more often in patients ≥ 75 years (aSHR 1.166, 95% CI 1.108-1.227), while no difference between the sexes existed in patients aged 65-74 years. Ablations were performed less often in women aged <65 years (aSHR 0.908, 95% CI 0.826-0.998) and ≥75 years (aSHR 0.521, 95% CI 0.354-0.766), whereas there was no difference in patients aged 65-74 years.

Conclusion: Women used more AAD than men in all age groups but underwent fewer cardioversion and ablation procedures when aged <65 years.