Europace最新文献

Aims: Pulsed field ablation (PFA) is described as non-thermal, but data from oncology and cardiology show thermal effects occur. The specific waveform parameters influencing thermal energy development during PFA are unclear. The aim of this study is to numerically evaluate the thermal effects of PFA on myocardial and oesophageal tissue at various peak voltage conditions.

Methods and results: A three-dimensional computer model of the left atrium quantified thermal effects from PFA at peak voltages of 1, 1.5, and 2 kV. Energy was applied using a bipolar configuration with far-field and symmetry boundaries set as electrically insulating. A monophasic waveform with a 100 μs pulse width and a 1 s gap between pulses was applied for a total of 50 pulses, mimicking clinical conditions. Minimal temperature rise in the oesophagus was observed with 1 kV pulses (214.5 J). At 1.5 and 2 kV (570.3 and 1.23 kJ), temperatures reached 46.3°C and >62°C, respectively, after a single pulse train. These findings suggest that repeated applications could lead to even higher temperatures, especially if good tissue contact is obtained. These results align with data from other medical fields using pulsed field treatments.

Conclusion: Thermal effects from PFA depend on the total energy deposited, with peak voltage being a significant factor. Current commercially available PFA systems have the potential to induce collateral thermal injury with repeated applications of pulsed field energy. This highlights the need for careful monitoring and adjustment of PFA parameters in clinical settings.

Background: Intercostal EV-ICD leads may work better inn contact with the pericardium thereby directing pacing and defibrillation energy toward excitable myocytes. We report three-month safety and performance outcomes with a second-generation intercostal EV-ICD lead paired with standard, commercially available ICD pulse generators (PGs).

Methods: Subjects undergoing a transvenous ICD (TV-ICD) procedure received a concomitant intercostal EV-ICD lead system. The intercostal EV-ICD lead was connected sequentially to a PG in a left pectoral and then a left mid-axillary location. EV-ICD lead assessment included sensing and defibrillation of induced ventricular arrhythmias (IVA) and pacing capture. The intercostal EV-ICD system was followed in a "recording only" mode and the control TV-ICD system in "therapy delivery" mode to compare stored events. Devices were evaluated prior to hospital discharge, 2 weeks, 1 month, 2 months and 3 months post implant. Defibrillation testing was repeated prior to lead removal.

Results: 20/20(100%) were successfully implanted (median implant time of 9 minutes). Two major lead complications were reported over a mean of 82 days: (1) lead movement and (2) infection of both the TV-ICD and EV-ICD systems. Intraoperative pacing capture was achieved with the integrated bipolar configuration in 19 of 20 (95%) subjects. Pacing capture with the EV-ICD system was tolerated in all subjects, with over 90% feeling no pain after a one-month recovery from the procedure. Induced VF episodes were sensed in all subjects and defibrillated successfully in 17 of 17 patients (100%) with a left mid-axillary PG and 19 of 20 patients (95%) with a left pectoral PG. Sensing and defibrillation were successful in 18 of 18 (100%) tested prior to lead removal.

Conclusions: In this pilot experience with a second generation intercostal EV-ICD lead implantation, sensing and defibrillation of induced VF was successful when paired with a standard ICD PG from either a left midaxillary or pectoral pocket.

Study identifier: NCT Number: NCT05791032, URL: https://clinicaltrials.gov/study/NCT05791032.

Background: Genome-wide association studies (GWASs) identified common single nucleotide polymorphisms (SNPs) in more than 100 genomic regions associated with atrial fibrillation (AF). We aimed to identify novel AF genes in Taiwanese population by multi-stage GWAS.

Methods: In exploratory stage, we did GWAS with whole genome genotypes (4,512,191 SNPs) in 516 AF Patients from National Taiwan University AF registry (NTUAFR) and 5160 normal sinus rhythm controls from Taiwan Biobank. Significant loci were replicated in 1002 independent patients and 2003 controls, and in UK biobank. Expression quantitative trait locus (eQTL) mapping and transcriptome-wide association study (TWAS) were performed to implicate functional significance.

Results: Stage I GWAS revealed 3 loci associated with AF with genome-wide significance level, including one close to PITX2 gene (chromosome 4q25, rs2723329, minor allele frequency [MAF] 0.50 vs 0.41, P=1.53×10-10), another close to RAP1A gene (also to previous KCND3; chromosome 1p13.2, rs7525578, MAF 0.17 vs 0.07, P= 1.24×10-26) and one novel locus close to HNF4G gene (chromosome 8q21.13, rs2980218, MAF 0.44 vs 0.35, P=2.19×10-9). They were validated in stage II population. The eQTL analyses showed significant colocalization of 1p13.2 locus with RAP1A gene expression in fibroblasts and 8q21.13 locus with HNF4G expression in lymphocytes. There's significant association of RAP1A gene expression in fibroblasts and HNF4G in lymphocytes and brain with AF.

Conclusions: GWAS in Taiwan revealed PITX2 and RAP1A/KCND3 loci and novel AF locus (HNF4G) with most significant locus in the RAP1A locus. RAP1A and HNF4G genes may implicate fibrosis, metabolic and neurogenic pathways in pathogenesis of AF.

Aims: The aim of this study was to perform an external validation of an automatic machine learning algorithm for heart rhythm diagnostics using smartphone photoplethysmography (PPG) recorded by patients with atrial fibrillation (AF) and atrial flutter (AFL) pericardioversion in an unsupervised ambulatory setting.

Methods and results: Patients undergoing cardioversion for AF or AFL performed 1-min heart rhythm recordings peri-cardioversion at least twice daily for 4-6 weeks, using an iPhone 7 smartphone running a PPG application (CORAI Heart Monitor) simultaneously with a single-lead ECG recording (KardiaMobile). The algorithm uses support vector machines (SVM) to classify heart rhythm from smartphone-PPG. The algorithm was trained on PPG recordings made by patients in a separate cardioversion cohort. Photoplethysmography recordings in the external validation cohort were analysed by the algorithm. Diagnostic performance was calculated by comparing the heart rhythm classification output to the diagnosis from the simultaneous ECG recordings (gold standard).In total 460 patients performed 34 097 simultaneous PPG and ECG recordings, divided into 180 patients with 16 092 recordings in the training cohort and 280 patients with 18 005 recordings in the external validation cohort. Algorithm classification of the PPG recordings in the external validation cohort diagnosed AF with sensitivity, specificity and accuracy of 99.7/99.7/99.7%, and AF/AFL with sensitivity, specificity and accuracy of 99.3/99.1/99.2%.

Conclusion: A machine learning based algorithm demonstrated excellent performance in diagnosing atrial fibrillation and atrial flutter from smartphone-PPG recordings in an unsupervised ambulatory setting, minimizing the need for manual review and ECG verification, in elderly cardioversion populations.

Current ablation strategies for persistent atrial fibrillation (AF) remain suboptimal, with success rates around 50%. Pulmonary vein isolation (PVI) serves as the cornerstone of ablation, yet adjunctive strategies have shown inconsistent results in randomized controlled trials. This review critically examines the outcomes and limitations of these approaches while identifying key barriers to success, including incomplete understanding of AF mechanisms, patient heterogeneity, technical challenges in achieving durable lesions, and the absence of standardized procedural endpoints. A novel electro-anatomically guided ablation protocol is proposed, integrating advanced mapping techniques and procedural endpoints aimed at achieving AF termination. Furthermore, it discusses emerging technologies such as pulsed field ablation (PFA), which hold promise for enhancing safety and long-term outcomes. These insights provide a framework for future research and the optimization of persistent AF ablation strategies.

Background: Ibrutinib, a widely used anti-cancer drug, is known to significantly increase the susceptibility to atrial fibrillation (AF). While it is recognized that drugs can reshape the gut microbiota, influencing both therapeutic effectiveness and adverse events, the role of gut microbiota in ibrutinib-induced AF remains largely unexplored.

Method: Utilizing 16S rRNA gene sequencing, faecal microbiota transplantation, metabonomics, electrophysiological examination, and molecular biology methodologies, we sought to validate the hypothesis that gut microbiota dysbiosis promotes ibrutinib-associated AF and to elucidate the underlying mechanisms.

Result: We found that ibrutinib administration pre-disposes rats to AF. Interestingly, ibrutinib-associated microbial transplantation conferred increased susceptibility to AF in rats. Notably, ibrutinib induced a significantly decrease in the abundance of Lactobacillus gasseri (L. gasseri), and oral supplementation of L. gasseri or its metabolite, butyrate (BA), effectively prevented rats from ibrutinib-induced AF. Mechanistically, BA inhibits the generation of reactive oxygen species, thereby ameliorating atrial structural remodelling. Furthermore, we demonstrated that ibrutinib inhibited the growth of L. gasseri by disrupting the intestinal barrier integrity.

Conclusion: Collectively, our findings provide compelling experimental evidence supporting the potential efficacy of targeting gut microbes in preventing ibrutinib-associated AF, opening new avenues for therapeutic interventions.

Aims: The optimal substrate ablation approach for post-myocardial infarction (MI) ventricular tachycardia (VT) is unknown. Proposed ablation targets are prone to individual interpretation making the ablation outcome potentially operator dependent. Evoked delayed potentials (EDPs) are a well-defined target. Evoked delayed potential ablation was effective in preventing post-MI VT recurrence in a prior study. The aims of this study were to assess long-term outcomes of EDP ablation in a large multicentre cohort of post-MI patients and to compare ablation outcomes between centres with and without prior experience in EDP ablation.

Methods and results: Patients with post-MI VT undergoing ablation in one centre performing EDP ablation since 2013 and five centres without prior experience in EDP ablation were prospectively included. A uniform mapping protocol including right ventricular extra-stimulation aiming to EDP identification was followed. Ablation endpoints were EDP elimination and VT non-inducibility. Patients were followed for VT recurrence, mortality, heart transplant, and left ventricular assist device implantation. In total, 130 patients were included. The protocol was successfully performed in 99%, and in 94%, EDPs were identified and ablated. In total, 78% of patients were rendered non-inducible. Ventricular tachycardia-free survival was 78% [95% confidence interval (CI) 71-85] and 71% (95% CI 63-80) at 6 and 12 months, respectively. No difference in VT-free survival was observed among centres with and without prior experience in EPD ablation.

Conclusion: In a large multicentre prospective cohort of patients with post-MI VT, EDP ablation resulted in good long-term outcomes. Importantly, VT recurrence rates did not differ among centres with and without prior experience in EDP ablation, indicating that this approach can be easily reproduced by operators previously not familiar with the technique.