Evolution of the "Internet Plus Health Care" Mode Enabled by Artificial Intelligence: Development and Application of an Outpatient Triage System.

BACKGROUND: Although new technologies have increased the efficiency and convenience of medical care, patients still struggle to identify specialized outpatient departments in Chinese tertiary hospitals due to a lack of medical knowledge. OBJECTIVE: The objective of our study was to develop a precise and subdividable outpatient triage system to improve the experiences and convenience of patient care. METHODS: We collected 395,790 electronic medical records (EMRs) and 500 medical dialogue groups. The EMRs were divided into 3 data sets to design and train the triage model (n=387,876, 98%) and test (n=3957, 1%) and validate (n=3957, 1%) it. The triage system was altered based on the current BERT (Bidirectional Encoder Representations from Transformers) framework and evaluated by recommendation accuracies in Xinhua Hospital using the cancellation rates in 2021 and 2022, from October 29 to December 5. Finally, a prospective observational study containing 306 samples was conducted to compare the system's performance with that of triage nurses, which was evaluated by calculating precision, accuracy, recall of the top 3 recommended departments (recall@3), and time consumption. RESULTS: With 3957 (1%) records each, the testing and validation data sets achieved an accuracy of 0.8945 and 0.8941, respectively. Implemented in Xinhua Hospital, our triage system could accurately recommend 79 subspecialty departments and reduce the number of registration cancellations from 16,037 (3.83%) of the total 418,714 to 15,338 (3.53%) of the total 434200 (P<.05). In comparison to the triage system, the performance of the triage nurses was more accurate (0.9803 vs 0.9153) and precise (0.9213 vs 0.9049) since the system could identify subspecialty departments, whereas triage nurses or even general physicians can only recommend main departments. In addition, our triage system significantly outperformed triage nurses in recall@3 (0.6230 vs 0.5266; P<.001) and time consumption (10.11 vs 14.33 seconds; P<.001). CONCLUSIONS: The triage system demonstrates high accuracy in outpatient triage of all departments and excels in subspecialty department recommendations, which could decrease the cancellation rate and time consumption. It also improves the efficiency and convenience of clinical care to fulfill better the usage of medical resources, expand hospital effectiveness, and improve patient satisfaction in Chinese tertiary hospitals.

Randomized Controlled Trial Comparing Training of Transseptal Puncture With or Without Intracardiac Echocardiography.

BACKGROUND: Intracardiac echocardiography (ICE) has been widely used in the catheter ablation of atrial fibrillation (AF). However, the value of ICE in the training of transseptal puncture (TSP) is unclear. METHODS: ICE-Training Study was a single-center, parallel-group, unmasked, randomized controlled trial registered in ChineseClinicalTrials.gov. Participants were randomly assigned (1:1) to different groups (1) the ICE simulator training group (ICE-ST), in which TSP was trained and performed under the guidance of both ICE and x-ray; and (2) the conventional simulator training group (Con-ST), in which TSP was trained and performed only under the guidance of x-ray. The trainees need to undergo the training stage and the evaluation stage. RESULTS: From October 2022 to December 2022, 18 consecutive fellows (age 32.4 ± 4.4 years, 12 males) without experience of TSP were included. The training period (16.9 ± 6.6 vs. 29.6 ± 8.7 times, p = 0.003) and the fluoroscopy time (120.3 ± 25.3 vs. 189.3 ± 40.2 s, p < 0.001) of the ICE-ST group was significantly shorter than that of the Con-ST group. No significant difference was found in the comprehensive performance of TSP in the ICE-ST group (composite score 96.7 ± 5.7) and the Con-ST group (composite score 95.9 ± 6.3, p = 0.62), but the selection of TSP sites in the ICE-ST group was commonly better than that in the Con-ST group. CONCLUSIONS: ICE could improve the efficiency of TSP training and optimize the site of TSP to facilitate catheter manipulation in the ablation. TRIAL REGISTRATION: ChineseClinicalTrials.gov identifier: ChiCTR2200058377.

Impact of sodium-glucose cotransporter 2 inhibitor on recurrence and cardiovascular outcomes after catheter ablation for atrial fibrillation in patients with heart failure.

BACKGROUND: The impact of sodium-glucose cotransporter 2 inhibitors (SGLT2i) on atrial fibrillation (AF) recurrence outcomes and adverse cardiovascular outcomes in heart failure (HF) patients after AF ablation is unknown. OBJECTIVE: We investigated whether SGLT2i reduces the risk of AF recurrence and adverse cardiovascular outcomes in HF patients after AF ablation. METHODS: HF patients with AF undergoing catheter ablation between January 2017 and December 2022 from the China-AF Registry were included. Patients were stratified into 2 groups on the basis of the use of SGLT2i at discharge and were 1:1 matched by propensity score, with SGLT2i using (n = 368) and non-SGLT2i using (n = 368) in each group. The primary outcome was AF recurrence after a 3-month blanking period. RESULTS: During a total of 1315 person-years of follow-up, AF recurred in 83 patients (22.6%) in the SGLT2i group and 132 patients (35.8%) in the non-SGLT2i group. SGLT2i was associated with a lower risk of AF recurrence (adjusted hazard ratio, 0.56; 95% CI, 0.43-0.74; P < .001). The composite risk of cardiovascular death, thrombotic events, or cardiovascular hospitalization was significantly lower in the SGLT2i group compared with those without SGLT2i (adjusted hazard ratio, 0.58; 95% CI, 0.41-0.80; P = .001). Although there was a trend toward benefit, the differences in all-cause mortality, cardiovascular death, or thrombotic events were insignificant between the 2 groups. CONCLUSION: The use of SGLT2i was associated with a lower risk of AF recurrence and the composite outcome of cardiovascular death, thrombotic events, or cardiovascular hospitalization after catheter ablation for AF in patients with HF.

Small Left Ventricle in Patients With Atrial Fibrillation Is Associated With Increased Cardiovascular Risk.

BACKGROUND: It is still unclear whether small left ventricle (LV) is an adverse structural prognostic feature in patients with atrial fibrillation (AF). OBJECTIVES: The purpose of this study was to evaluate the association between small LV and risk of cardiovascular events in AF population. METHODS: From the China-AF registry, 7,764 patients with AF were enrolled and divided into groups with normal, small, and large LV size based on left ventricular end-diastolic dimension (LVEDD) measurement per the American Society of Echocardiography references. Cox models were used to assess the association between LV size or LVEDD with composite cardiovascular events (cardiovascular death, ischemic stroke or systemic embolism, or major bleeding). RESULTS: There were 308 (4.0%) participants assessed with small LV who were older, with lower body mass and blood pressure, and fewer comorbidities, and 429 (5.5%) were identified with large LV. Compared with the normal LV group, small LV and large LV were significantly associated with higher incidence of composite cardiovascular events (adjusted HR [aHR]: 1.54 [95% CI: 1.07-2.20] for small LV; aHR: 1.36 [95% CI: 1.02-1.81] for large LV) and cardiovascular death (aHR: 1.94 [95% CI: 1.14-3.28] for small LV; aHR: 1.83 [95% CI: 1.24-2.69] for large LV). Small LV was also associated with increased risk of major bleeding [aHR: 2.21 [95% CI: 1.01-4.86]). A U-shaped relationship between LVEDD and composite cardiovascular events was identified (Pnonlinear < 0.001). CONCLUSIONS: In a prospective AF cohort, small LV was independently associated with an increased risk of cardiovascular events, which needed consideration in risk stratification and management for patients with AF. (ChiCTR-OCH-13003729).

Characteristics of Right-Sided Accessory Pathways Associated With Right Cardiac Veins.

BACKGROUND: The anatomy of myocardial fibers around the right cardiac veins (RCVs) and their roles in accessory pathways (APs) are rarely reported. METHODS: Six RCV-APs were identified from 566 patients with right-sided APs. Mapping of retrograde atrial activation was performed using CARTO 3 system under orthodromic tachycardia or right ventricular pacing. Venography of RCVs was acquired at the earliest retrograde atrial activation. RESULTS: Patients enrolled had a median age of 30 (11-51) years, 5 of them were male. Venography of RCVs could be classified into 3 distinct patterns based on the identified ventricular branches, right marginal vein only (type I; n=3), both right marginal vein and anterior cardiac veins (type II; n=2), and anterior cardiac vein only (type III; n=1). Patients with type I venography had rS QRS pattern in lead V1, negative delta wave in lead III and negative or isoelectric delta wave in lead aVF. However, patients with type II and III venography had QS QRS patterns in lead V1 and variable patterns of delta wave in inferior leads. Earliest retrograde atrial activation was found at a median of 16.75 (14.60-20.00) mm away from the tricuspid annulus, all with A larger than V. At the earliest retrograde atrial activation, far-field ventricular electrogram was found 30 ms later than QRS onset in 1 patient under sinus rhythm. AP conduction was eliminated by mechanical pressure in 2 and by radiofrequency ablation in 4 at the ostium of the veins colocalizing with the earliest retrograde activation of the right atrium. No recurrence was observed during 36 (10-60) months follow-up. CONCLUSIONS: The RCV-AP is a rare form of right-sided APs characterized by atrial insertions distant from the annulus. ECG-speculated ventricular insertion sites conformed to the location of identified RCVs.

Efficiency and Durability of EIVOM on Acute Reconnection After Mitral Isthmus Bidirectional Block.

BACKGROUND: Reconnection after mitral isthmus (MI) block with radiofrequency ablation is common. OBJECTIVES: The aim of this study was to investigate the effects of ethanol infusion in the vein of Marshall (EIVOM) on acute reconnection after MI bidirectional block. METHODS: Patients with persistent atrial fibrillation who were scheduled to receive radiofrequency ablation for the first time were randomly assigned to the radiofrequency catheter ablation (RFCA) group (n = 44) or the EIVOM group (n = 45). The RFCA group's strategy was bilateral pulmonary vein ablation and linear ablation; in the EIVOM group, EIVOM was performed first. The primary endpoint was acute reconnection 30 minutes after MI bidirectional block. RESULTS: A total of 89 patients (average age 62.9 years; 57.3% male) were enrolled. The average duration for persistent atrial fibrillation was 2.3 years. Before observation, all patients in the EIVOM group achieved MI bidirectional block (45 of 45 [100%]), compared with 84.1% (37 of 44) in the RFCA group. After the observation, 3 cases of MI reconnection occurred in the EIVOM group and 13 cases in the RFCA group (6.7% vs 35.1%; P < 0.05). After additional ablation, the final MI block rates in the EIVOM and RFCA groups were 97.8% (44 of 45) and 72.7% (32 of 44), respectively. During a 1-year follow-up, 8 of 45 patients who underwent EIVOM had recurrent atrial fibrillation, compared with 14 of 44 in the RFCA group (17.8% vs 31.8%; P < 0.01). CONCLUSIONS: EIVOM can reduce acute reconnection after MI bidirectional block and significantly increase first-pass MI block.

Evaluation of an algorithm-guided photoplethysmography for atrial fibrillation burden using a smartwatch.

BACKGROUND: Wearable devices based on the PPG algorithm can detect atrial fibrillation (AF) effectively. However, further investigation of its application on long-term, continuous monitoring of AF burden is warranted. METHOD: The performance of a smartwatch with continuous photoplethysmography (PPG) and PPG-based algorithms for AF burden estimation was evaluated in a prospective study enrolling AF patients admitted to Beijing Anzhen Hospital for catheter ablation from September to November 2022. A continuous Electrocardiograph patch (ECG) was used as the reference device to validate algorithm performance for AF detection in 30-s intervals. RESULTS: A total of 578669 non-overlapping 30-s intervals for PPG and ECG each from 245 eligible patients were generated. An interval-level sensitivity of PPG was 96.3% (95% CI 96.2%-96.4%), and specificity was 99.5% (95% CI 99.5%-99.6%) for the estimation of AF burden. AF burden estimation by PPG was highly correlated with AF burden calculated by ECG via Pearson correlation coefficient (R2 = 0.996) with a mean difference of -0.59 (95% limits of agreement, -7.9% to 6.7%). The subgroup study showed the robust performance of the algorithm in different subgroups, including heart rate and different hours of the day. CONCLUSION: Our results showed the smartwatch with an algorithm-based PPG monitor has good accuracy and stability in continuously monitoring AF burden compared with ECG patch monitors, indicating its potential for diagnosing and managing AF.

Impact of Sodium-Glucose Cotransporter 2 Inhibitor on Recurrence After Catheter Ablation for Atrial Fibrillation in Patients With Diabetes: A Propensity-Score Matching Study and Meta-Analysis.

BACKGROUND: The association between sodium-glucose cotransporter 2 inhibitors (SGLT2i) and atrial fibrillation (AF) recurrence after catheter ablation among patients with diabetes and AF remains unclear. METHODS AND RESULTS: Patients with AF undergoing initial catheter ablation with a history of diabetes from the China AF registry were included. Patients using SGLT2i were identified and matched by propensity score with non-SGLT2i patients in a 1:3 ratio. The main outcome was AF recurrence during the 18-month follow-up. A total of 138 patients with diabetes with SGLT2i therapy and 387 without SGLT2i were analyzed. AF recurrence occurred in 37 patients (26.8%) in the SGLT2i group and 152 patients (39.3%) in the non-SGLT2i group during a total of 593.3 person-years follow-up. The SGLT2i group was associated with lower AF recurrence compared with the non-SGLT2i group (hazard ratio, 0.63 [95% CI, 0.44-0.90], P=0.007). A total of 4 studies were analyzed in our meta-analysis demonstrating that SGLT2i was associated with lower AF recurrence after catheter ablation (odds ratio, 0.61 [95% CI, 0.54-0.69]; P<0.001, I2=0.0%). CONCLUSIONS: Our prospective study coupled with a meta-analysis demonstrated a lower risk of AF recurrence with the use of SGLT2i among patients with diabetes after AF ablation.

Catheter ablation versus medical therapy for atrial fibrillation with prior stroke history: a prospective propensity score-matched cohort study.

BACKGROUND: Patients with atrial fibrillation (AF) and prior stroke history have a high risk of cardiovascular events despite anticoagulation therapy. It is unclear whether catheter ablation (CA) has further benefits in these patients. METHODS: AF patients with a previous history of stroke or systemic embolism (SE) from the prospective Chinese Atrial Fibrillation Registry study between August 2011 and December 2020 were included in the analysis. Patients were matched in a 1:1 ratio to CA or medical treatment (MT) based on propensity score. The primary outcome was a composite of all-cause death or ischemic stroke (IS)/SE. RESULTS: During a total of 4.1 ± 2.3 years of follow-up, the primary outcome occurred in 111 patients in the CA group (3.3 per 100 person-years) and in 229 patients in the MT group (5.7 per 100 person-years). The CA group had a lower risk of the primary outcome compared to the MT group [hazard ratio (HR) = 0.59, 95% CI: 0.47-0.74, P < 0.001]. There was a significant decreasing risk of all-cause mortality (HR = 0.43, 95% CI: 0.31-0.61, P < 0.001), IS/SE (HR = 0.73, 95% CI: 0.54-0.97, P = 0.033), cardiovascular mortality (HR = 0.32, 95% CI: 0.19-0.54, P < 0.001) and AF recurrence (HR = 0.33, 95% CI: 0.30-0.37, P < 0.001) in the CA group compared to that in the MT group. Sensitivity analysis generated consistent results when adjusting for time-dependent usage of anticoagulants. CONCLUSIONS: In AF patients with a prior stroke history, CA was associated with a lower combined risk of all-cause death or IS/SE. Further clinical trials are warranted to confirm the benefits of CA in these patients.

Effect of interventional embolization based on absolute ethanol for peripheral arteriovenous malformations.

BACKGROUND: Interventional embolization schedules based on absolute ethanol are usually used for peripheral arteriovenous malformations (PAVMs), and clinicians often choose the scheme according to the classification. AIM: To evaluate different interventional embolization schedules based on absolute ethanol for PAVMs. METHODS: A retrospective study was performed of 165 patients with PAVMs treated with interventional embolization based on absolute ethanol in Henan Provincial People's Hospital from January 2018 to May 2021. PAVMs were classified as type II (n = 67), type III (n = 81) and type IV (n = 17) according to the Yakes classification system, including 123 maxillofacial, 13 trunk and 29 limbs. Effectiveness of embolization was based on PAVM devascularization on angiography: 100% (total), 90%~99% (near-total), 70%~90% (substantial), 30%~70% (partial) and 0%~30% (failure). RESULTS: PAVMs were classified as type II (n = 67), type III (n = 81) and type IV (n = 17) according to the Yakes classification system, including 123 maxillofacial (74.55%), 13 trunk (7.88%) and 29 limbs (17.58%). There are statistical differences in the angiographic outcomes among different Yakes classification and between different methods (P < 0.05), and there was a statistical difference in the failure rates among different Yakes classification (P < 0.05). CONCLUSIONS: PAVMs occur maxillofacial usually, and Type II can achieve better effect by spring coil and absolute ethanol, while Type III and Type IV have no ideal effect by Pingyangmycin + iodized oil + PVA + absolute ethanol and spring coil + absolute ethanol, respectively. Both the two happen to be complications, and wound accounts the highest.

Epicardial Roof-Dependent Macro-Re-Entrant Tachycardia After Ablation of Atrial Fibrillation: Electrophysiological Characteristics and Ablation.

BACKGROUND: Epicardial roof-dependent macro-re-entrant tachycardias (epi-RMAT) after catheter ablation of persistent atrial fibrillation are not rare but the prevalence and characteristics remain unclear. OBJECTIVES: The purpose of this study was to investigate the prevalence, electrophysiological characteristics and ablation strategy of recurrent epi-RMATs after ablation of atrial fibrillation. METHODS: A total of 44 consecutive patients with 45 roof-dependent RMATs after atrial fibrillation ablation were enrolled. High-density mapping and appropriate entrainment were performed to diagnose epi-RMATs. RESULTS: Epi-RMAT was identified in 15 patients (34.1%). Under the right lateral view, the activation pattern can be briefly classified into clockwise re-entry (n = 4), counterclockwise re-entry (n = 9), and bi-atrial re-entry (n = 2). Five (33.3%) had a pseudofocal activation pattern. All epi-RMATs had continuous slow or no conduction zone with a mean width of 21.3 ± 12.3 mm traversing both pulmonary antra, and 9 (60.0%) had missing cycle length of >10% actual cycle length. Compared with endocardial RMAT (endo-RMAT), epi-RMAT required longer ablation time (9.60 ± 4.98 minutes vs 3.68 ± 3.42 minutes; P < 0.001), more floor line ablation (93.3% vs 6.7%; P < 0.001), and electrogram-guided posterior wall ablation (78.6% vs 3.3%; P < 0.001). Electric cardioversion was required in 3 patients (20.0%) with epi-RMATs, whereas all endo-RMATs were terminated by radiofrequency applications (P = 0.032). Posterior wall ablation was performed under esophagus deviation in 2 patients. We did not observe a significant difference in the recurrence of atrial arrhythmias between patients with epi-RMATs and endo-RMATs after the procedure. CONCLUSIONS: Epi-RMATs are not uncommon after roof or posterior wall ablation. An explicable activation pattern with a conduction obstacle in the dome and appropriate entrainment is critical for the diagnosis. The effectiveness of posterior wall ablation may be restricted by the risk of esophagus impairment.

GFANet: Gated Fusion Attention Network for skin lesion segmentation.

Automatic segmentation of skin lesions is crucial for diagnosing and treating skin diseases. Although current medical image segmentation methods have significantly improved the results of skin lesion segmentation, the following major challenges still affect the segmentation performance: (i) segmentation targets have irregular shapes and diverse sizes and (ii) low contrast or blurred boundaries between lesions and background. To address these issues, this study proposes a Gated Fusion Attention Network (GFANet) which designs two progressive relation decoders to accurately segment skin lesions images. First, we use a Context Features Gated Fusion Decoder (CGFD) to fuse multiple levels of contextual features, and then a prediction result is generated as the initial guide map. Then, it is optimized by a prediction decoder consisting of a shape flow and a final Gated Convolution Fusion (GCF) module, where we iteratively use a set of Channel Reverse Attention (CRA) modules and GCF modules in the shape flow to combine the features of the current layer and the prediction results of the adjacent next layer to gradually extract boundary information. Finally, to speed up network convergence and improve segmentation accuracy, we use GCF to fuse low-level features from the encoder and the final output of the shape flow. To verify the effectiveness and advantages of the proposed GFANet, we conduct extensive experiments on four publicly available skin lesion datasets (International Skin Imaging Collaboration [ISIC] 2016, ISIC 2017, ISIC 2018, and PH2) and compare them with state-of-the-art methods. The experimental results show that the proposed GFANet achieves excellent segmentation performance in commonly used evaluation metrics, and the segmentation results are stable. The source code is available at https://github.com/ShiHanQ/GFANet.

Prospective randomized comparison between upgraded '2C3L' vs. PVI approach for catheter ablation of persistent atrial fibrillation: PROMPT-AF trial design.

BACKGROUND: In randomized studies, the strategy of pulmonary vein antral isolation (PVI) plus linear ablation has failed to increase success rates for persistent atrial fibrillation (PeAF) ablation when compared with PVI alone. Peri-mitral reentry related atrial tachycardia due to incomplete linear block is an important cause of clinical failures of a first ablation procedure. Ethanol infusion (EI) into the vein of Marshall (EI-VOM) has been demonstrated to facilitate a durable mitral isthmus linear lesion. OBJECTIVE: This trial is designed to compare arrhythmia-free survival between PVI and an ablation strategy termed upgraded '2C3L' for the ablation of PeAF. STUDY DESIGN: The PROMPT-AF study (clinicaltrials.gov 04497376) is a prospective, multicenter, open-label, randomized trial using a 1:1 parallel-control approach. Patients (n = 498) undergoing their first catheter ablation of PeAF will be randomized to either the upgraded '2C3L' arm or PVI arm in a 1:1 fashion. The upgraded '2C3L' technique is a fixed ablation approach consisting of EI-VOM, bilateral circumferential PVI, and 3 linear ablation lesion sets across the mitral isthmus, left atrial roof, and cavotricuspid isthmus. The follow-up duration is 12 months. The primary end point is freedom from atrial arrhythmias of >30 seconds, without antiarrhythmic drugs, in 12 months after the index ablation procedure (excluding a blanking period of 3 months). CONCLUSIONS: The PROMPT-AF study will evaluate the efficacy of the fixed '2C3L' approach in conjunction with EI-VOM, compared with PVI alone, in patients with PeAF undergoing de novo ablation.

Integrated exploration of experimentation and molecular simulation in ester-containing polyimide dielectrics.

With the growing development of film capacitors in various applications, the requirements for polymer dielectrics have increased accordingly. In this work, a series of ester-cotaining polyimide (EPI) dielectrics were designed and fabricated. Futhermore, integrated exploration of experimentation and molecular simulation is proposed to achieve polymer dielectrics with advanced comprehensive performance, as well as to analyze the dielectric mechanism in-depth. The EPIs show superior thermal resistance and dielectric properties. A Weibull breakdown strength of 440-540 MV m-1, permittivity of 3.52-3.85, dissipation factor of 0.627-0.880% and theoretical energy density of 3.13-4.90 J cm-3 were obtained for the EPIs. The relationship between microscopic parameters and dielectric behavior was investigated in detail. According to the experimental and calculated results, there is close correlation between dipolar moment density (µ/V vdw) and dielectric permittivity (ε r). It is deduced that the integrated research of experiments and molecular simulation would be an effective strategy to reveal the dielectric mechanism as well as assist in the molecular design of polymer dielectrics.

Fascicular ventricular tachycardia arising from the left side His and its adjacent region: a subset of upper septal idiopathic left ventricular tachycardia.

AIMS: Fascicular ventricle tachycardia (FVT) arising from the proximal aspect of left His-Purkinje system (HPS) has not been specially addressed. Current study was to investigate its clinical, electrocardiographic, and electrophysiological characteristics. METHODS AND RESULTS: Eighteen patients who were identified as this rare FVT were consecutively enrolled, and their scalar electrocardiogram and electrophysiological data were collected and analysed. The ventricular tachycardia (VT) morphology was similar to sinus rhythm (SR) in eight patients, left bundle branch block type in one patient, right bundle branch block type in seven patients, and both narrow and wide QRS type in two patients. During VT, right-sided His potential preceded the QRS with His-ventricle (H-V) interval of 36.3 ± 12.4 ms, which was shorter than that during SR (-51.4 ± 8.6 ms) (P = 0.002). The earliest Purkinje potentials (PPs) were recorded within 7 ± 3 mm of left-side His and preceded the QRS by 49.1 ± 14.0 ms. Mapping along the left anterior fascicle and left posterior fascicle revealed an antegrade activation sequence in all with no P1 potentials recorded. In the two patients with two VT morphologies, the earliest PP was documented at the same site, and the activation sequence of HPS remained antegrade. Ablation at the earliest PP successfully eliminated the tachycardia, except one patient who developed complete atrial-ventricular block and two patients who abandoned ablations. After at least 12 months follow-up, 15 patients were free from any recurrences. CONCLUSIONS: Fascicular ventricle tachycardia arising from the proximal aspect of left HPS was featured by recording slightly shorter H-V interval and absence of P1 potentials. Termination of VT requires ablation at the left-sided His or its adjacent region.

Revisiting the characteristics and ablation strategy of biatrial tachycardias: a case series and systematic review.

AIMS: To describe the role of left atrial (LA) epicardial conduction and targets of ablation in biatrial tachycardias (BiATs). METHODS AND RESULTS: Consecutive patients with BiAT diagnosed by high-density mapping and appropriate entrainment were enrolled. A systematic review of case reports or series was then performed. Biatrial tachycardia was identified in 20 patients aged 63.5 ± 11.1 years. Among them, eight had LA epicardial conduction, including four via the ligament of Marshall, two via myocardial fibres between the great cardiac vein (GCV) and LA, one via septopulmonary bundle, and one via myocardial fibres between the posterior wall and coronary sinus. Ablation was targeted at the anatomical isthmus in 14, including 5 undergoing vein of Marshall ethanol infusion and 2 undergoing ablation in the GCV. Another six underwent ablation at interatrial connections, including one with septopulmonary bundle at the fossa ovalis and five at the atrial insertions of Bachmann's bundle. After a mean follow-up of 8.7 ± 3.8 months, five patients had recurrence of atrial fibrillation/flutter. Systematic review enrolled 87 patients in previous and the present reports, showing a higher risk of impairment in atrial physiology in those targeting interatrial connections (30.4 vs. 5.0%, P < 0.001) but no significant difference in short- and long-term effectiveness. CONCLUSION: Left atrial epicardial conduction is common in BiATs and affects the ablation strategy. Atrial physiology is a major concern in selecting the target of intervention.

Vein of Marshall ethanol infusion: First-step or adjunctive choice for perimitral atrial tachycardia?

BACKGROUND: Perimitral atrial tachycardia (PMAT) is the most frequent type of iatrogenic atrial tachycardia (AT) after atrial fibrillation (AF) ablation. Vein of Marshall ethanol infusion (EIVOM) is a promising technique in mitral isthmus (MI) ablation. METHODS: A total of 165 patients with PMAT were divided into three groups according to ablation strategies, including RF only group (n = 89), RF-EIVOM group (initial RF ablation with adjunctive EIVOM, n = 28), and EIVOM-RF group (first-step EIVOM with touch-up RF ablation, n = 48). Acute and follow-up procedure outcomes were evaluated. RESULTS: PMAT terminated in 89.9%, 89.3%, and 93.7% of patients in RF only, RF-EIVOM and EIVOM-RF groups, respectively (p = .715), with complete MI block achieved in 80.9%, 89.3%, and 95.8% of patients (EIVOM-RF vs. RF only, p = .012). First-step utilization of EIVOM was associated with a significant shortening of RF ablation time at MI (EIVOM-RF 2.1 ± 1.3 min, RF only 7.9 ± 5.9 min, RF-EIVOM 6.8 ± 5.8 min; p < .001) and a decrease in the proportion of patients need ablation within coronary sinus (CS, EIVOM-RF 14.6%, RF only 61.8%, RF-EIVOM 64.3%; p < .001). After a mean follow-up of 12.1 ± 6.2 months, AF/AT recurred in 39 (43.8%), 6 (21.4%), and 12 (25.0%) patients in RF only, RF-EIVOM, and EIVOM-RF group (RF-EIVOM vs. RF only, p = .026; EIVOM-RF vs. RF only, p = .022). CONCLUSIONS: EIVOM was associated with an enhanced acute MI block rate as well as reduced AF/AT recurrence. First-step utilization of EIVOM promises to significantly simplify the RF ablation process. CONDENSED ABSTRACT: PMAT is the most common type of iatrogenic AT after AF ablation procedures. EIVOM contributed to a higher acute MI block rate and lower arrhythmia recurrence risk during follow-up. First-step utilization of EIVOM significantly reduced the need for radiofrequency ablation at MI and inside CS with the advantage of creating a homogenous, transmural lesion and eliminating epicardial connections.

The adjunctive effect for left pulmonary vein isolation of vein of Marshall ethanol infusion in persistent atrial fibrillation.

OBJECTIVE: This study sought to assess the effect of ethanol infusion into the vein of Marshall (EIVOM) on the acute success of left pulmonary vein (LPV) isolation in persistent atrial fibrillation (PeAF). METHODS AND RESULTS: A total of 313 patients with drug-resistant PeAF were enrolled (135 in Group 1 and 178 in Group 2). In Group 1, EIVOM was firstly performed, followed by radiofrequency ablation (RFA) including bilateral pulmonary vein isolation (PVI) and linear ablation at roofline, cavotricuspid isthmus, and mitral isthmus (MI). In Group 2, PVI and linear ablations were completed with RFA. First-pass isolation of the LPV was achieved in 119 (88.1%) and 132 (74.2%) patients in Groups 1 and 2, respectively (P = 0.002). The rate of acute pulmonary vein reconnection (PVR) was significantly lower in Group 1 (9.6% vs. 22.5%, P = 0.003). About half of acute PVR occurred in the carina with or without EIVOM. CONCLUSION: EIVOM is effective in achieving a higher first-pass isolation and a lower acute PVR of LPV in PeAF.

Risk Factors for Left Ventricular Thrombus Formation in Patients with Dilated Cardiomyopathy.

BACKGROUND: Left ventricular thrombus (LVT) is a common complication of dilated cardiomyopathy (DCM), causing morbidity and mortality. METHODS: This study retrospectively analyzed patients with DCM from January 2002 to August 2020 in Beijing Anzhen Hospital. Clinical characteristics were compared between the LVT group and the age and sex 1:4 matched with the LVT absent group. The receiver operator characteristic (ROC) curve was plotted to evaluate the diagnostic value of D-dimer predicting LVT occurrence in DCM. RESULTS: A total of 3,134 patients were screened, and LVT was detected in 72 (2.3%) patients on echocardiography. The patients with LVT had higher D-dimer, fibrinogen, and lower systolic blood pressure than those without LVT. The ejection fraction (EF) was lower and left ventricular end-systolic diameter was larger in the LVT group. Severe mitral regurgitation (MR) was more common in the LVT absent groups. The prevalence of atrial fibrillation was lower in the LVT group. The ROC curve analysis yielded an optimal cut-off value of 444 ng/mL DDU (D-dimer units) for D-dimer to predict the presence of LVT. Multivariable binary logistic regression analysis revealed that EF (OR = 0.90, 95% CI = 0.86-0.95), severe MR (OR = 0.19, 95% CI = 0.08-0.48), and D-dimer level (OR = 15.4, 95% CI = 7.58-31.4) were independently associated with LVT formation. CONCLUSION: This study suggested that elevated D-dimer levels (>444 ng/mL DDU) and reduced EF were independently associated with increased risk of LVT formation. Severe MR could decrease the incidence of LVT.

Angular-Shaped Boron Nitride Nanosheets with a High Aspect Ratio to Improve the Out-of-Plane Thermal Conductivity of Polyimide Composite Films.

Polyimide/boron nitride nanosheet (PI/BNNS) composite films have potential applications in the field of electrical devices due to the superior thermal conductivity and outstanding insulating properties of the boron nitride nanosheet. In this study, the boron nitride nanosheet (BNNS-t) was prepared by the template method using sodium chloride as the template, and B2O3 and flowing ammonia as the boron and nitrogen sources, respectively. Then, the PI/BNNS-t composite films were investigated with different loading of BNNS-t as thermally conductive fillers. The results show that BNNS-t has a high aspect ratio and a uniform lateral dimension, with a large dimension and a thin thickness, and there are a few nanosheets with angular shapes in the as-obtained BNNS-t. The synergistic effect of the above characteristics for BNNS-t is beneficial to constructing the three-dimensional heat conduction network of the PI/BNNS-t composite films, which can significantly improve the out-of-plane thermal conduction properties. And then, the out-of-plane thermal conductivity of the PI/BNNS-t composite film achieves 0.67 W m-1 K-1 at 40% loading, which is nearly 3.5 times that of the PI film.