Effects of radiofrequency catheter ablation for premature ventricular complexes originating from the right ventricular outflow tract on right ventricular function.

INTRODUCTION: This study aimed to elucidate the relationship between premature ventricular complexes (PVCs) and right ventricular (RV) dysfunction, and the effects of radiofrequency catheter ablation (RFCA) on RV function. METHODS: A total of 110 patients (age, 50.8 ± 14.4 years; 30 men) without structural heart disease who had undergone RFCA for RV outflow tract (RVOT) PVCs were retrospectively included. RV function was assessed using fractional area change (FAC) and global longitudinal strain (GLS) before and after RFCA. Clinical data were compared between the RV dysfunction (n = 63) and preserved RV function (n = 47) groups. The relationship between PVC burden and RV function was analyzed. Change in RV function before and after RFCA was compared between patients with successful and failed RFCA. RESULTS: PVC burden was significantly higher in the RV dysfunction group than in the preserved RV function group (p < .001). FAC and GLS were significantly worse in proportion to PVC burden (p < .001 and p < .001, respectively). The risk factor associated with RV dysfunction was PVC burden [odds ratio (95% confidence interval), 1.092 (1.052-1.134); p < .001]. Improvement in FAC (13.0 ± 8.7% and -2.5 ± 5.6%, respectively; p < .001) and GLS (-6.8 ± 5.7% and 2.1 ± 4.2%, respectively; p < .001) was significant in the patients with successful RFCA, compared to the patients in whom RFCA failed. CONCLUSIONS: Frequent RVOT PVCs are associated with RV dysfunction. RV dysfunction is reversible by successful RFCA.

Late recurrence of atrial fibrillation 5 years after catheter ablation: predictors and outcome.

AIMS: Atrial fibrillation (AF) is a chronic progressive disease that continuously recurs even after successful AF catheter ablation (AFCA). We explored the mechanism of long-term recurrence by comparing patient characteristics and redo-ablation findings. METHODS AND RESULTS: Among the 4248 patients who underwent a de novo AFCA and protocol-based rhythm follow-up at a single centre, we enrolled 1417 patients [71.7% male, aged 60.0 (52.0-67.0) years, 57.9% paroxysmal AF] who experienced clinical recurrences (CRs), and divided them according to the period of recurrence: within one year (n = 645), 1-2 years (n = 339), 2-5 years (n = 308), and after 5 years (CR>5 yr, n = 125). We also compared the redo-mapping and ablation outcomes of 198 patients. In patients with CR>5 yr, the proportion of paroxysmal AF was higher (P = 0.031); however, the left atrial (LA) volume (quantified by computed tomography, P = 0.003), LA voltage (P = 0.003), frequency of early recurrence (P < 0.001), and use of post-procedure anti-arrhythmic drugs (P < 0.001) were lower. A CR>5 yr was independently associated with a low LA volume [odds ratio (OR) 0.99 (0.98-1.00), P = 0.035], low LA voltage [OR 0.61 (0.38-0.94), P = 0.032], and lower early recurrence [OR 0.40 (0.23-0.67), P < 0.001]. Extra-pulmonary vein triggers during repeat procedures were significantly greater in patients with a CR>5 yr, despite no difference in the de novo protocol (P for trend 0.003). The rhythm outcomes of repeat ablation procedures did not differ according to the timing of the CR (log-rank P = 0.330). CONCLUSIONS: Patients with a later CR exhibited a smaller LA volume, lower LA voltage, and higher extra-pulmonary vein triggers during the repeat procedure, suggesting AF progression.

Spin-Dependent Thermoelectric Power of Nanoislands.

The Seebeck effect explains the generation of electric voltage as a result of a temperature gradient. Its efficiency, defined as the ratio of the generated electric voltage to the temperature difference, is sensitive to local inhomogeneities that alter the scattering rate and the density of the conduction electrons. Spin-polarized Seebeck tunneling generates a distinct thermovoltage in spin-up and spin-down charge transport channels, which, as a key to spin caloritronics, focuses on transport phenomena related to spin and heat. Here, we report spatially resolved measurement of the spin-dependent thermovoltage in a tunneling junction formed by ferromagnetic Co nanoislands and a Ni tip using spin-dependent scanning tunneling thermovoltage microscopy (SP-STVthM). We resolve the nanoscale thermoelectric powers with respect to spin polarization, nanoisland size, stacking order of Co layers on a Cu substrate, and local sample heterogeneities. The observed thermally generated spin voltages are supported by first-principles and model calculations.

Pseudogap and Weak Multifractality in 2D Disordered Mott Charge-Density-Wave Insulator.

We investigate electronic states of Se-substituted 1T-TaS2 by scanning tunneling microscopy/spectroscopy (STM/STS), where superconductivity emerges from the unique Mott-charge-density-wave (Mott-CDW) state. Spatially resolved STS measurements reveal that a pseudogap replaces the Mott gap with the CDW gaps intact. The pseudogap has little correlation with the unit-cell-to-unit-cell variation in the local Se concentration but appears globally. The correlation length of the local density of states (LDOS) is substantially enhanced at the Fermi energy and decays rapidly at high energies. Furthermore, the statistical analysis of LDOS indicates the weak multifractal behavior of the wave functions. These findings suggest a correlated metallic state induced by disorder and provide a new insight into the emerging superconductivity in two-dimensional materials.

Electrophysiological significance of the interatrial conduction including cavo-tricuspid isthmus during atrial fibrillation.

KEY POINTS: The interatrial conduction, including Bachmann's bundle, the posterior septal conduction, the anterior septal conduction, and the cavo-tricuspid isthmus, contributes to the maintenance mechanisms of atrial fibrillation in a 3D biatrial model. The interatrial conduction ablation including a cavo-tricuspid isthmus ablation significantly affects the wave dynamics of atrial fibrillation (AF) and facilitates the AF termination or atrial tachycardia conversion of the AF after the circumferential pulmonary vein isolation. Additional cavo-tricuspid isthmus ablation after the circumferential pulmonary vein isolation improves long-term rhythm outcome after clinical AF catheter ablation. ABSTRACT: Although it is known that atrial fibrillation (AF) is mainly a left atrial (LA) disease, the role of the right atrium (RA) and interatrial conduction (IAC), including the cavo-tricuspid isthmus (CTI), has not been clearly defined. We tested AF wave dynamics with or without IAC in computational modelling and the rhythm outcome of AF catheter ablation (AFCA) including CTI ablation in clinical cohort data. We evaluated the dominant frequency (DF) in 3D biatrial AF simulations integrated with 3D-computed tomograms obtained from 10 patients. The IAC was implemented at Bachmann's bundle, posterior septum and the CTI. After virtual circumferential PV isolation (CPVI), we disconnected IACs one by one, and observed the wave dynamics. We compared the long-term rhythm outcome after CPVI alone and additional CTI ablation in 846 patients with AFCA. LA-DF was higher than RA-DF in AF (P < 0.001). After CPVI, the DF decreased significantly by additional IAC ablation (P = 0.003), especially in the LA (P = 0.016). The amount of DF reduction (P = 0.020) and rates of AF termination (P < 0.001) or AT conversion (P = 0.021) were significantly higher after IAC ablations including CTI than those without. In clinical AFCA, the AF recurrence rate was significantly lower in patients with additional CTI ablation than CPVI alone during 25 ± 20 months' follow-up (hazard ratio 0.60 [0.46-0.79], P < 0.001, Log rank P < 0.001). IAC contributes to the maintenance mechanism of AF, and IAC including CTI ablation affects AF wave dynamics, facilitating AF termination in 3D biatrial modelling. Additional CTI ablation after CPVI improves the long-term rhythm outcome in clinical AFCA, potentially in a paroxysmal type with accompanying atrial flutter, or atrial dimension close to normal.

A mesh-type flexible tip catheter vs a contact force catheter for catheter ablation of atrial fibrillation: A prospective nonrandomized 1:1 matched study.

INTRODUCTION: Mesh-type flexible tip (MFT) catheters allow clinicians to safely generate large radiofrequency lesions during catheter ablation of atrial fibrillation (AF), while contact force (CF) catheters provide better catheter-tissue contact. We compared the clinical outcomes of catheter ablation of AF using MFT and CF catheters in a prospective, nonrandomized manner. METHODS: We prospectively assigned 217 patients with AF (paroxysmal AF 73.5%; male 69.1%; 59.9 ± 10.7 years old) at a 1:1 ratio to ablation with MFT catheters (FlexAbility) or CF catheters (TactiCath). The primary endpoint was AF recurrence after a single procedure; the secondary endpoint was a response to antiarrhythmic drugs. RESULTS: After a mean follow-up of 22.3 ± 4.4 months, the clinical recurrence rate did not significantly differ between the two study groups (29.7% vs 30.2%; P = .941) (log-rank P = .838). The recurrence rate for atrial tachycardias (30.3% vs 9.7%; P = .035) and cardioversion rates (8.1% vs 1.9%; P = .024) were higher in the MFT group than CF group. At the final follow-up, sinus rhythm was maintained without antiarrhythmic drugs in 57.7% of the MFT group and 40.6% of the CF group (P = .010). No significant difference was found in the major complication rates between the two groups (0.9% vs 5.7%), although the ablation time was significantly longer in the MFT group (4192.1 ± 1080.2 vs 3583.8 ± 977.2 seconds; P < .001). CONCLUSION: MFT and CF catheters had similar effectiveness in achieving AF rhythm control during catheter ablation, and there was no significant difference between the two catheters with regard to overall safety.

A mendelian randomization analysis: The causal association between serum uric acid and atrial fibrillation.

BACKGROUND: Observational studies have shown that high levels of serum uric acid (UA) were associated with atrial fibrillation (AF). However, the causal effect of urate on the risk of AF is still unknown. To clarify the potential causal association between UA and AF, we performed a Mendelian randomization (MR) analysis using genetic instrumental variables (IVs). MATERIALS AND METHODS: From the Korean GWAS dataset of 633 patients with AF (mean age 50.6 ± 7.8 years, 80.9% male, Yonsei AF Ablation cohort) who underwent radiofrequency catheter ablation and the data from 3533 controls (from the Korea Genome Epidemiology Study), we selected 9 SNPs, with a P value less than .05, associated with an increased UA serum level. Additionally, we calculated the weighted genetic risk score (wGRS) using the selected 9 SNPs, to use it as an instrumental variable. A Mendelian randomization analysis was calculated by a 2-stage estimator method. RESULTS: The conventional association between the serum UA and AF was significant (P = .001) after adjusting for potential confounding factors. The SNP rs1165196 on SLC17A1 (F-statistics = 208.34, 0.18 mg/mL per allele change, P < .001) and wGRS (F-statistics = 222.26, 0.20 mg/mL per 1SD change, P < .001) were significantly associated with an increase in the UA level. The MR analysis was causally associated with rs1165196 (estimated odds ratio (OR), 0.21, 95% confidence interval (CI), 0.06-0.75, P = .017), but not wGRS (estimated OR, 1.07, 95% CI, 0.57-2.01, P = .832). CONCLUSION: The serum UA level was independently associated with the AF risk.

Trends and Outcome of Catheter Ablation of Atrial Fibrillation Over 9 Years　- Focus on Empirical Extra-Pulmonary Vein Ablation.

BACKGROUND: The Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial Part II (STAR-AF2) emphasized the importance of circumferential pulmonary vein isolation (CPVI) during AF ablation. Methods and Results: This study involved 2,297 consecutive patients (mean age, 58±11 years; 73.1% male, 70.1% paroxysmal AF) undergoing AF ablation from 2009 to 2017. We investigated the ablation lesion set, ablation time, catheter type, and clinical outcomes. Over the 9 years, the extra-pulmonary vein (PV) left atrial (LA) ablation rate (76.8% to 19.4%, P<0.001 for trend) and ablation time (P<0.001 for trend) decreased dramatically, whereas the 1-year recurrence rates decreased (21.8% to 14.1%, P=0.04 for trend). In persistent AF patients, the extra-PV LA ablation rate (91.4% to 55.3%, P<0.001) and ablation time (P<0.001) decreased after the STAR-AF2 report, but the 1-year recurrence rates remained similar (22.1% to 17.9%, P=0.281). A mesh-type flexible tip (MFT) catheter with a moderately increased radiofrequency power was used since 2012, and the MFT catheter was independently associated with a lower clinical recurrence compared to other irrigated-tip catheters (HR, 0.670; 95% CI: 0.559-0.803, P<0.001; log rank P=0.002) without increasing the procedure-related complications (OR, 1.434; 95% CI: 0.937-2.194, P=0.097). CONCLUSIONS: Over the 9 years the extra-PV LA ablation and 1-year recurrence rates in the AF ablation cohort decreased, in part due to improved catheter technology.

Surface Magnetism of Cobalt Nanoislands Controlled by Atomic Hydrogen.

Controlling the spin states of the surface and interface is key to spintronic applications of magnetic materials. Here, we report the evolution of surface magnetism of Co nanoislands on Cu(111) upon hydrogen adsorption and desorption with the hope of realizing reversible control of spin-dependent tunneling. Spin-polarized scanning tunneling microscopy reveals three types of hydrogen-induced surface superstructures, 1H-(2 × 2), 2H-(2 × 2), and 6H-(3 × 3), with increasing H coverage. The prominent magnetic surface states of Co, while being preserved at low H coverage, become suppressed as the H coverage level increases, which can then be recovered by H desorption. First-principles calculations reveal the origin of the observed magnetic surface states by capturing the asymmetry between the spin-polarized surface states and identify the role of hydrogen in controlling the magnetic states. Our study offers new insights into the chemical control of magnetism in low-dimensional systems.

Atomic-scale mapping of thermoelectric power on graphene: role of defects and boundaries.

The spatially resolved thermoelectric power is studied on epitaxial graphene on SiC with direct correspondence to graphene atomic structures by a scanning tunneling microscopy (STM) method. A thermovoltage arises from a temperature gradient between the STM tip and the sample, and variations of thermovoltage are distinguished at defects and boundaries with atomic resolution. The epitaxial graphene has a high thermoelectric power of 42 µV/K with a big change (9.6 µV/K) at the monolayer-bilayer boundary. Long-wavelength oscillations are revealed in thermopower maps which correspond to the Friedel oscillations of electronic density of states associated with the intravalley scattering in graphene. On the same terrace of a graphene layer, thermopower distributions show domain structures that can be attributed to the modifications of local electronic structures induced by microscopic distortions (wrinkles) of graphene sheet on the SiC substrate. The thermoelectric power, the electronic structure, the carrier concentration, and their interplay are analyzed on the level of individual defects and boundaries in graphene.

Wavefront distortion correction in scanning tunneling microscope image.

We report an algorithm to identify and correct distorted wavefronts in atomic resolution scanning tunneling microscope images. This algorithm can be used to correct nonlinear in-plane distortions without prior knowledge of the physical scanning parameters, the characteristics of the piezoelectric actuator, or individual atom positions. The 2D image is first defined as a sum of sinusoidal plane waves, where a nonlinear distortion renders a curve for an otherwise ideal linear wavefront. Using the Fourier transforms of local areas of the image, the algorithm generates a wavefront vector field. The identified wavefronts are subsequently linearized for each plane wave without changing lattice orders, giving rise to distortion corrections. Our algorithm is complementary to conventional post-processing algorithms that require prior detection of real space features, which can also be used to correct nonlinear distortions in 2D images acquired by other microscopy techniques.

Differentiating Left Atrial Pressure Responses in Paroxysmal and Persistent Atrial Fibrillation: Implications for Diagnosing Heart Failure With Preserved Ejection Fraction and Managing Atrial Fibrillation.

BACKGROUND: Increased left atrial pressure (LAP) contributes to dyspnea and heart failure with preserved ejection fraction in patients with atrial fibrillation (AF). The purpose of this study was to investigate the differences in baseline LAP and LAP response to rapid pacing between paroxysmal and persistent AF. METHODS AND RESULTS: This observational study prospectively enrolled 1369 participants who underwent AF catheter ablation, excluding those with reduced left ventricular ejection fraction. H2FPEF score was calculated by echocardiography and baseline characteristics. Patients underwent LAP measurements during AF, sinus rhythm, and heart rates of 90, 100, 110, and 120 beats per minute (bpm), induced by right atrial pacing and isoproterenol. The baseline LAP-peak in the persistent AF group consistently exceeded that in the paroxysmal AF (PAF) group across each H2FPEF score subgroup (all P<0.05). LAP-peak increased with pacing (19.5 to 22.5 mm Hg) but decreased with isoproterenol (20.4 to 18.4 mm Hg). Under pacing, patients with PAF exhibited a significantly lower LAP-peak (90 bpm) than those with persistent AF (17.7±8.2 versus 21.1±9.3 mm Hg, P<0.001). However, there was no difference in LAP-peak (120 bpm) between the 2 groups (22.1±8.1 versus 22.9±8.4 mm Hg, P=0.056) because the LAP-peak significantly increased with heart rate in the group with PAF. CONCLUSIONS: Patients with PAF exhibited lower baseline LAP with greater increases during rapid pacing compared with individuals with persistent AF, indicating a need to revise the H2FPEF score for distinguishing PAF from persistent AF and emphasizing the importance of rate and rhythm control in PAF for symptom control. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique Identifier: NCT02138695.

Socioeconomic disparities and cardio-cerebrovascular diseases: A nationwide cross-sectional study.

Background: Although socioeconomic status (SES) is considered a risk factor for cardio-cerebrovascular diseases (CCVDs), few studies have examined this association. In this cross-sectional study, we aimed to assess the prevalence and trends of CCVDs across different SES groups over a 12-year period in a representative Korean population. Methods: We analysed 47 745 economically active adults aged ≥30 and <65 years from 97 622 patients in the Korean National Health and Nutrition Examination Survey (2007-18), where a new independent sample of the population was examined each year. We categorised the participants into four groups based on education level and income. The prevalence of hypertension, diabetes mellitus, dyslipidaemia, and CCVD, including angina, myocardial infarction, and stroke, was analysed at four-year intervals. Results: Average age, urban residence, white-collar occupation, and body mass index >30 increased, whereas CCVD prevalence did not change significantly (P = 0.410) over the study period. Low education (odds ratio (OR) = 1.24; 95% confidence interval (CI) = 1.04-1.47, P < 0.001) and low income (OR = 1.14; 95% CI = 1.02-1.28, P = 0.017) were significant determinants of CCVD in addition to existing traditional risk factors. CCVD prevalence was significantly higher in both the low-education and low-income groups compared to the high-education and high-income groups every four years, with no significant change in this gap over the study period (P = 0.239). Conclusions: Despite the increase in the elderly population and the prevalence of obesity, the incidence of CCVDs in Korea has remained unchanged. Individuals with low education or low income had a significantly higher prevalence of CCVD, with the lowest SES group, defined by both low education and low income, consistently having the highest prevalence of CCVDs.

Effects of antiarrhythmic drug responsiveness and diagnosis-to-ablation time on outcomes after catheter ablation for persistent atrial fibrillation.

Background: The impact of delaying atrial fibrillation catheter ablation (AFCA) for antiarrhythmic drug (AAD) management on the disease course remains unclear. This study investigated AFCA rhythm outcomes based on the diagnosis-to-ablation time (DAT) and AAD responsiveness in participants with persistent AF (PeAF). Methods: We included data from 1038 AAD-resistant PeAF participants, all of whom had a clear time point for AF diagnosis, especially PeAF at diagnosis time, and had undergone an AFCA for the first time. Participants who experienced recurrences of paroxysmal type on AAD therapy were analyzed as a cohort of AAD-partial responders; those maintaining PeAF on AAD were AAD-non-responders. We determined the DAT cutoff for best discriminating long-term rhythm outcomes using a maximum log-likelihood estimation method based on the Cox proportional hazard regression model. Results: Of the participants (79.8% male; median age 61), 806 (77.6%) were AAD-non-responders. AAD-non-responders had a higher body mass index and a larger left atrial diameter than AAD-partial-responders. They also had a higher incidence of AF recurrence after AFCA (adjusted hazard ratio 1.75, 95% confidence interval 1.33-2.30; log-rank p < .001) compared to AAD-partial-responders. The maximum log-likelihood estimation showed bimodal cutoffs at 22 and 40 months. The optimal DAT cutoff rhythm outcome was 22 months, which discriminated better in the AAD-partial-responders than in the AAD-non-responders. Conclusions: Both DAT and AAD responsiveness influenced AFCA rhythm outcomes. Delaying AFCA to a DAT of longer than 22 months was inadvisable, particularly in the participants in whom PeAF was changed to paroxysmal AF during AAD therapy.

Artificial intelligence estimated electrocardiographic age as a recurrence predictor after atrial fibrillation catheter ablation.

The application of artificial intelligence (AI) algorithms to 12-lead electrocardiogram (ECG) provides promising age prediction models. We explored whether the gap between the pre-procedural AI-ECG age and chronological age can predict atrial fibrillation (AF) recurrence after catheter ablation. We validated a pre-trained residual network-based model for age prediction on four multinational datasets. Then we estimated AI-ECG age using a pre-procedural sinus rhythm ECG among individuals on anti-arrhythmic drugs who underwent de-novo AF catheter ablation from two independent AF ablation cohorts. We categorized the AI-ECG age gap based on the mean absolute error of the AI-ECG age gap obtained from four model validation datasets; aged-ECG (≥10 years) and normal ECG age (<10 years) groups. In the two AF ablation cohorts, aged-ECG was associated with a significantly increased risk of AF recurrence compared to the normal ECG age group. These associations were independent of chronological age or left atrial diameter. In summary, a pre-procedural AI-ECG age has a prognostic value for AF recurrence after catheter ablation.

Clinical Characteristics and Rhythm Outcomes in Patients With Atrial Myopathy After Successful Catheter Ablation of Atrial Fibrillation.

BACKGROUND: Although successful atrial fibrillation (AF) ablation can maintain sinus rhythm and reduce the left atrial (LA) dimension, blunted LA reverse remodeling can be observed in patients with atrial myopathy. We explored the potential mechanisms and long-term outcomes in patients with blunted LA reverse remodeling after successful AF catheter ablation. METHODS AND RESULTS: We included 1685 patients who underwent baseline and 1-year follow-up echocardiograms, had a baseline LA dimension ≥40 mm, and did not have a recurrence of AF within a year. The patients were divided into tertile groups according to the delta value of the change in LA dimension on the preprocedure and 1-year postprocedure echocardiography. After propensity score matching for age, sex, AF type, and LA dimension, 1272 patients were finally included in the analyses (424 in each group; the least/blunted, moderate, and the most reverse remodeling group). The patients in the T1 group (blunted LA reverse remodeling) were independently associated with higher left ventricular mass index (odds ratio [OR], 1.014 [95% CI, 1.005-1.022], P=0.001), change in ΔH2FPEF score (heavy, hypertensive, atrial fibrillation, pulmonary hypertension, elder, filling pressure) score (OR, 1.445 [95% CI, 1.121-1.861], P=0.004), ventricular epicardial adipose tissue volume (OR, 1.010 [95% CI, 1.003-1.017], P=0.003), thinner LA wall thickness (OR, 0.461 [95% CI, 0.271-0.785], P=0.004), lower LA voltage (OR, 0.670 [95% CI, 0.499-0.899], P=0.008), and showed higher long-term AF recurrence (log-rank P<0.001) than other groups. CONCLUSIONS: Blunted LA reverse remodeling after AF catheter ablation, which is suggestive of atrial myopathy, was independently associated with a larger ventricular epicardial adipose tissue volume and worsening of H2FPEF score. Blunted LA reverse remodeling after AF catheter ablation was also an independent predictor for higher recurrences of AF post-1-year AF catheter ablation.

The Effects of Radiofrequency Catheter Ablation for Atrial Fibrillation on Right Ventricular Function.

BACKGROUND AND OBJECTIVE: The effects of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) on right ventricular (RV) function are not well known. METHODS: Patients who underwent RFCA for AF and underwent pre- and post-procedural echocardiography were enrolled consecutively. Fractional area change (FAC), RV free-wall longitudinal strain (RVFWSL), and RV 4-chamber strain including the ventricular septum (RV4CSL) were measured. Changes in FAC, RVFWSL, and RV4CSL before and after RFCA were compared among paroxysmal AF (PAF), persistent AF (PeAF), and long-standing persistent AF (LSPeAF) groups. RESULTS: A total of 164 participants (74 PAF, 47 PeAF, and 43 LSPeAF; age, 60.8 ± 9.8 years; men, 74.4%) was enrolled. The patients with PeAF and LSPeAF had worse RV4CSL (p<0.001) and RVFWSL (p<0.001) than those with PAF and reference values. Improvements in RVFWSL and RV4CSL after RFCA were significant in the PeAF group compared with the PAF and LSPeAF groups (ΔRV4CSL, 8.4% [5.1, 11.6] in PeAF vs. 1.0% [-1.0, 4.1] in PAF, 1.9% [-0.2, 4.4] in LSPeAF, p<0.001; ΔRVFWSL, 9.0% [6.9, 11.5] in PeAF vs. 0.9% [-1.4, 4.9] in PAF, 1.0% [-1.0, 3.6] in LSPeAF, p<0.001). In patients without recurrence, improvements in RVFWSL and RV4CSL after RFCA were significant in the PeAF group compared to the LSPeAF group. CONCLUSIONS: RV systolic function is more impaired in patients with PeAF and LSPeAF than in those with PAF. RV systolic function is more improved after RFCA in patients with PeAF than in those with PAF or LSPeAF.

Anti- and pro-fibrillatory effects of pulmonary vein isolation gaps in human atrial fibrillation digital twins.

Although pulmonary vein isolation (PVI) gaps and extrapulmonary vein triggers contribute to recurrence after atrial fibrillation (AF) ablation, their precise mechanisms remain unproven. Our study assessed the impact of PVI gaps on rhythm outcomes using a human AF digital twin. We included 50 patients (76.0% with persistent AF) who underwent catheter ablation with a realistic AF digital twin by integrating computed tomography and electroanatomical mapping. We evaluated the final rhythm status, including AF and atrial tachycardia (AT), across 600 AF episodes, considering factors including PVI level, PVI gap number, and pacing locations. Our findings revealed that antral PVI had a significantly lower ratio of AF at the final rhythm (28% vs. 56%, p = 0.002) than ostial PVI. Increasing PVI gap numbers correlated with an increased ratio of AF at the final rhythm (p < 0.001). Extra-PV induction yielded a higher ratio of AF at the final rhythm than internal PV induction (77.5% vs. 59.0%, p < 0.001). In conclusion, our human AF digital twin model helped assess AF maintenance mechanisms. Clinical trial registration: https://www.clinicaltrials.gov ; Unique identifier: NCT02138695.

Atomistic Probing of Defect-Engineered 2H-MoTe2 Monolayers.

Point defects dictate various physical, chemical, and optoelectronic properties of two-dimensional (2D) materials, and therefore, a rudimentary understanding of the formation and spatial distribution of point defects is a key to advancement in 2D material-based nanotechnology. In this work, we performed the demonstration to directly probe the point defects in 2H-MoTe2 monolayers that are tactically exposed to (i) 200 °C-vacuum-annealing and (ii) 532 nm-laser-illumination; and accordingly, we utilize a deep learning algorithm to classify and quantify the generated point defects. We discovered that tellurium-related defects are mainly generated in both 2H-MoTe2 samples; but interestingly, 200 °C-vacuum-annealing and 532 nm-laser-illumination modulate a strong n-type and strong p-type 2H-MoTe2, respectively. While 200 °C-vacuum-annealing generates tellurium vacancies or tellurium adatoms, 532 nm-laser-illumination prompts oxygen atoms to be adsorbed/chemisorbed at tellurium vacancies, giving rise to the p-type characteristic. This work significantly advances the current understanding of point defect engineering in 2H-MoTe2 monolayers and other 2D materials, which is critical for developing nanoscale devices with desired functionality.

Self-assembled nanowires with giant Rashba split bands.

We investigated Pt-induced nanowires on the Si(110) surface using scanning tunneling microscopy (STM) and angle-resolved photoemission. High resolution STM images show a well-ordered nanowire array of 1.6 nm width and 2.7 nm separation. Angle-resolved photoemission reveals fully occupied one-dimensional (1D) bands with a Rashba-type split dispersion. Local dI/dV spectra further indicate well-confined 1D electron channels on the nanowires, whose density of states characteristics are consistent with the Rashba-type band splitting. The observed energy and momentum splitting of the bands are among the largest ever reported for Rashba systems, suggesting the Pt-Si nanowire as a unique 1D giant Rashba system. This self-assembled nanowire can be exploited for silicon-based spintronics devices as well as the quest for Majorana fermions.