Background The effects of epicardial connections (ECs) involving pulmonary veins (PVs) in atrial fibrillation (AF) ablation have been revealed recently. However, no systematic approaches to identify and ablate the ECs were established. Methods Patients with AF undergoing radiofrequency (RF) catheter ablation were retrospectively analyzed. ECs were identified when (1) PV isolation (PVI) cannot be achieved after first‐pass isolation; (2) PVI was still absent although the conduction gap was detected and ablated; (3) the earliest activation area (EAA) was revealed located within the PV antrum distant from the initial ablation line using high‐density mapping (HDM) technique; (4) focal ablation at the EAA was effective to achieve PVI. Relevant pacing maneuvers were performed to elucidate ECs’ bidirectional conduction. Results Overall, 36 ECs were identified and ablated in 35/597 (5.86%) patients. Among the 35 patients with ECs, at least one PV insertion of ECs was located at the carina region. The most common pattern was a single breakthrough in 31 (88.6%) patients, followed by multiple breakthroughs in 3 and wide breakthroughs in 1. The median distance from EAA to the initial ablation line was 10.0 mm. The average number of RF energy delivery was 1.75 ± 1.00, and single RF delivery was adequate in 16/36 (44.4%) patients. Continuous potentials were present at the EAA in 9/34 (26.5%) patients. Conclusion ECs were confirmed and ablated successfully in 5.86% (35/597) AF patients using HDM. PV insertions of ECs were mainly located at the carina region. Continuous potentials might assist in the prediction of ECs.

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The bipolar reverse polarity characteristic was not a practical method for identifying target in idiopathic OTVA ablation. The unipolar EGM-derived quantitative criteria have better predictive performance than visual inspection of the QS characteristic and are likely to reduce unnecessary ablation sites.

Pulmonary vein isolation (PVI) is the cornerstone therapy of atrial fibrillation (AF). Radiofrequency catheter ablation (RFCA) is performed using a point-by-point method to achieve durable PVI. However, this procedure remains complex and time-consuming, and the long-term clinical outcomes are still not satisfactory. Recently, there has been increasing interest in the clinical application of high-power short-duration (HPSD) approaches in the field of RFCA. HPSD ablation, distinguishing it from the conventional ablation strategy, delivers RF energy at a high power and saves the dwell time at each site. It is unknown whether the HPSD approach can bring some gratifying changes in the field of RF energy ablation. A number of experimental studies and clinical studies have been conducted regarding this topic. The review aimed to summarize the research findings and evaluate the procedural efficiency, safety, and clinical outcomes of the HPSD approach based on the evidence available to date.

ObjectiveAntithrombotic therapy in patients with nonvalvular atrial fibrillation (NVAF) concomitant with the acute coronary syndrome (ACS) or underwent percutaneous coronary intervention (PCI) is challenging and has evolved in recent years. However, real-world data on this issue about antithrombotic regimens at discharge and its evolving trend were relatively scarce, especially in China.MethodsA total of 2,182 patients with NVAF and ACS/PCI were enrolled from 2017 to 2019. A total of 1,979 patients were finally analyzed and divided in three sequential cohorts: cohort 1 (2017), n = 674; cohort 2 (2018), n = 793; and cohort 3 (2019), n = 512. Baseline characteristics and antithrombotic therapy at discharge were analyzed by cohort.ResultsIn our cross-sectional study, the majority of patients (59.6%) received dual antiplatelet therapy (DAPT). Over the 3 years, DAPT prescription reduced from nearly 70% to <50% (P trend < 0.001), while triple therapy (TT)/double therapy (DT) increased from 27.2 to 50.0% (P trend < 0.001). This trend was also seen in different subgroups stratified by CHA2DS2-VASc score, HAS-BLED score, coronary artery disease type, or management type, and was validated after multivariate adjustment. Persistent atrial fibrillation and history of congestive heart failure, hypertension, diabetes mellitus, and stroke/transient ischemic attack/systemic embolism were the independent predictors of TT/DT use, while ACS, PCI, or advanced chronic kidney disease was related with more DAPT prescription.ConclusionThere is a shift of antithrombotic regime at discharge for patients with NVAF with recent ACS/PCI with reducing DAPT prescription and increasing TT/DT prescription. While the appropriate antithrombotic regimen for patients with NVAF having ACS/PCI is still underused in China.

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Boron-doped carbon catalysts are synthesized via a liquid-phase electrodeposition technique using methanol-containing graphene nucleating agent and B 2 O 3 dopant as the reaction solution. The relationship between boron-doped content and specific surface area (SSA), as well as their influence on electrocatalytic activity for oxygen reduction reaction, is studied by changing the concentration of B 2 O 3 . When the concentrations of B 2 O 3 are 23.94 and 14.36 mol ml -1 , respectively, boron-doped content and SSA reach the peak values of 0.53 at.% and 18.476 m 2 g -1 . The data of electrochemical tests, such as onset potential of -0.016 V and transferred electron number of 3.74-3.77 in the range of -0.5 to -0.9 V, exhibit that the catalyst with a boron-doped content of 0.47 at.% and an SSA of 18.476 m 2 g -1 has the best electrocatalytic activity in all the synthesized samples. The enhanced electrocatalytic activity is ascribed to a synergistic effect originating from boron-doped content and SSA, in which the SSA contributes more. The experimental results have important guiding significance to maximize the oxygen reduction activity of catalysts and elucidate that it tends to design and synthesize catalysts with large SSA compared with doping.

Boron‐doped carbon catalysts are prepared by a novel method combining hot filament chemical vapor deposition technique with high temperature annealing treatment. Nano‐boron powders are coated by thin diamond layers and then the coated nano‐boron powders are annealed for different times at 1,300 °C in vacuum. The morphology, microstructure, and chemical bonding states of the synthetized materials have been investigated by scanning electron microscope (SEM), X‐ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT‐IR), and X‐ray photoelectron spectroscopy (XPS), respectively. The results indicate that boron atoms have diffused into the carbon lattice and the content of doping boron rises gradually with the increase of annealing time. The characteristic signal of the B‐C bond will vanish and of the signal B4C will appear, if the annealing time is too long. The experimental results of rotating disk electrode (RDE) voltammetry illustrate that the catalyst obtained after annealing for 2 h has the highest electrocatalytic oxygen reduction reaction (ORR) activity. The response current characterized by chronoamperometry exhibits that the deposits with a higher catalytic activity have a poorer stability and methanol tolerance.