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The presence of bipolar low-voltage zone (LVZ) is a predictor of AF recurrence after PV isolation (PVI). However, changes of wavefront and bipole directions may cause different electrogram characteristics. We aimed to investigate whether using omnipolar maximum voltage (Vmax) map derived from high density (HD) Grid mapping catheter could assess LVZ and AF ablation outcome accurately.Fifty paroxysmal AF patients (27 males, 57.8 ± 9.5 years old) who underwent 3D mapping guided PVI were enrolled. Left atrial voltage mapping during sinus rhythm before ablation was performed. The significant LVZ (0.5 mV with area 5 cmPVI was performed in all patients, and there were 2 patients (4%) who also received additional non-PV triggers ablation. After a follow-up of 11.4 ± 5.4 months, recurrence of AF occurred in 12 patients (24%). The presence of a significant LVZ was less detected by omnipolar Vmax map, compared to HD wave map (24.0% vs. 58.0%, p = 0.001). LVZ detected by omnipolar Vmax map independently predicted the AF recurrence (odds ratio 16.91; 95% CI, 3.17-90.10; p = 0.001).LVZ detected by omnipolar Vmax map accurately predicts the AF recurrence following ablation in paroxysmal AF, compared to conventional bipolar and HD wave maps, suggesting the omnipolar Vmax map can precisely define the atrial substrate property.

Background: The presence of abnormal substrate of left atrium is a predictor of atrial fibrillation (AF) recurrence after pulmonary vein isolation. We aimed to investigate the isochronal late activation mapping to access the abnormal conduction velocity for predicting AF ablation outcome. Methods: Forty-five paroxysmal AF patients (30 males, 57.8±8.7 years old) who underwent pulmonary vein isolation were enrolled. Isochronal late activation mapping was retrospectively constructed with 2 different windows of interest: from onset of P wave to onset of QRS wave on surface electrocardiography (W1) and 74 ms tracking back from the end of P wave (W2). Deceleration zone was defined as regions with 3 isochrones (DZa) or ≥4 isochrones (DZb) within a 1 cm radius on the isochronal late activation mapping, and the estimated conduction velocity (ECV) are 0.27 m/s and Results: Pulmonary vein isolation was performed in all patients, and there were 2 patients (4.4%) received additional extrapulmonary vein ablation. After a mean follow-up of 12.7±4.5 months, recurrence of AF occurred in 14 patients (31.1%). Patients with the presence of DZb in W2 had higher AF recurrence (Kaplan-Meier event rate estimates: HR, 9.41 [95% CI, 2.61–33.90]; log-rank P Conclusions: Deceleration zone detected by isochronal late activation mapping represents a critical AF substrate, it accurately predicts the AF recurrence following ablation in patients with paroxysmal AF.

Introduction: Ventricular arrhythmia (VA) from the left ventricular summit (LVS) is a common origin of VA, which resulting LV dysfunction in some patients. However, the predictors of LV cardiomyopathy were not well-elucidated. The present study sought to investigate the risk factor of LV cardiomyopathy and the outcome in patients with LVS VA Methods: Between 2013 and 2018, a total of 139 patients (60.7% men; mean age 53.2 ± 13.9 years-old) underwent catheter ablation for LVS VA from two centers. Detailed patient demographics, electrocardiograms, electrophysiological characteristics, and clinical outcomes were extracted for analysis. LV cardiomyopathy was defined as LV ejection fraction (LVEF) Results: Acute procedural success was achieved in 92.8 % of patients. There were 40 patients (28.8%) with LV cardiomyopathy, and the mean LVEF improved from 37.5 ± 9.3% to 48.5 ± 10.2% after ablation ( p < 0.001). After multivariate analysis, the independent predictors of LV dysfunction were wider QRS duration of the VA (odds ratio [OR]1.02; 95% confidence interval [CI]: 1.00-1.04; p = 0.046) and the absolute earliest activation time discrepancy (AEAD) between epicardium and endocardium (OR 1.05; 95% confidence interval CI: 1.00-1.09; p = 0.048). After ablation, the LV function was completely recovered in 20 patients (50%). The predictors for irreclaimable LV function included wider PVC QRS duration (OR 1.09; 95% CI: 1.02-1.17; p = 0.012) and poorer LVEF (OR 0.85; 95% CI: 0.74-0.97; p = 0.020). Conclusion: In patients with VA from LVS, PVC QRS duration and AEAD predicted the deteriorating LV systolic function. Catheter ablation could reverse the LV remodeling. Narrower QRS duration and better LVEF predicted a better recovery of LV function after ablation.

Background The mechanisms underlying angiotensin receptor-neprilysin inhibitor (ARNi) suppression of ventricular arrhythmia (VA) are unclear. This study aimed to investigate the mechanism of ARNi-related suppression of VA in a heart failure (HF) model. Methods New Zealand white rabbits (n = 6 per group) were assigned to normal, HF [4 weeks of left ascending artery (LAD) ligation], angiotensin receptor blocker (ARB, valsartan at 27 mg/kg/day for 3 weeks after 1 week of LAD ligation), and ARNi (sacubitril at 34 mg/kg/day and valsartan at 27 mg/kg/day for 3 weeks after 1 week of LAD ligation) groups. Experiments involving echocardiogram, optical mapping, histological of trichrome stain and immunostain, and flow cytometry were performed. Results HF group had larger left ventricular (LV) internal dimensions in diastole and systole, and lower LV ejection fraction and fractional shortening than normal, ARB, and ARNi groups. HF group had a prolonged action potential duration (APD) and decreased conduction velocity (CV), which was mitigated in ARB and ARNi groups. HF group had a prolonged QRS duration, QT and QTc intervals, which was reversed in ARB and ARNi groups. HF group had a steeper maximum slope of APD restitutions, which was attenuated in normal, ARB, and ARNi groups. HF group had increased number of phase singularities (PSs) and VA inducibility than normal, ARB, and ARNi groups. A higher content of fibrosis was found in HF group than that in normal, ARB, and ARNi groups. Compared to ARB group, ARNi had a lower context of fibrosis. HF group had more peripheral blood CD4+ and CD8+ cells count than normal, ARB, and ARNi group. Conclusions In a rabbit model of ischemic HF, ventricular arrhythmogenesis could be suppressed by ARNi treatment. This appears to be mediated by reversing changes in the APD, CV, maximum slope of the APDR, PSs, fibrosis, and inflammation.

BACKGROUND A recent study suggested to develop and implement more interacted material for preprocedural education to decrease patients' anxiety about the atrial fibrillation (AF) ablation. This study compared the effectiveness of using either newly developed virtual reality (VR) materials (VR group) or paper-based materials (paper group) on giving AF preprocedural education. METHODS This study consequentially enrolled 33 AF patients preparing for ablation from November 2019 to October 2020. After enrollment, patients were randomized as either paper (n = 22) or VR (n = 11) groups. RESULTS In comparison with the baseline stage, at the posteducation stage, the degree of improvement in patients' self-assessed self-efficacy on AF ablation knowledge was higher among VR group patients than those in the paper group. At the posteducation stage, the patients' satisfaction to preprocedural education and used materials were higher among the VR group than that among the paper group. In addition to meet their needs and give accurate medical information, VR group patients reported that VR materials increased the effectiveness of education, increased their preparedness for AF catheter ablation, achieved paperless purposes, and willing to recommend VR materials to others. Operators subjectively reported that the periprocedure cooperation was increased both among paper and VR group patients after preprocedural education for the details of procedure. Better preparedness of VR group patients was supported by less periprocedure pain, anxiety, and impatience than those among paper group patients. CONCLUSION Interactive VR-based materials are superior to the paper-based materials to provide patients immerse and imagine the journey and detail knowledge of AF catheter ablation before the procedure and better prepared patients for the procedure.

Catheter ablation for tachyarrhythmia via superior approach has been used in patients without possible inferior vena cava access such as in cases of venous occlusion or complex anomaly. Difficulty in catheter manipulation, instability, number of required vascular access, and radiation exposure of operator had been described in the procedure. Application of three-dimensional (3-D) mapping system in catheter ablation via superior approach could navigate the guiding catheter and provide more precise ablation. We reported four cases receiving catheter ablation due to atrioventricular nodal reentry tachycardia, atrial fibrillation and right ventricular arrhythmia via superior approach facilitated by 3-D mapping system with fewer vascular access and catheters.

Autonomic system plays a pivotal role in the pathogenesis of paroxysmal atrial fibrillation (AF). Skin sympathetic nerve activity (SKNA) is a noninvasive tool for assessing sympathetic tone. However, data on changes in SKNA after ablation are limited. Here, we retrospectively enrolled 37 patients with symptomatic drug-refractory paroxysmal AF who underwent pulmonary vein isolation (PVI) with radiofrequency ablation (RFA) or cryoablation (CBA). SKNA was measured from the chest and right arm 1 day prior to ablation, as well as 1 day and 3 months after ablation. One day after ablation, the SKNA-Arm increased from 517.1 µV (first and third quartiles, 396.0 and 728.0, respectively) to 1226.2 µV (first and third quartiles, 555.2 and 2281.0), with an increase of 179.8% (125% and 376.0%) (p < 0.001); the SKNA-Chest increased from 538.2 µV (first and third quartiles, 432.9 and 663.9) to 640.0 µV (first and third quartiles, 474.2 and 925.6), with an increase of 108.3% (95.6% and 167.9%) (p = 0.004), respectively. In those without recurrence, there was a significant increase in SKNA 1 day after ablation as compared with those before ablation. Twelve patients received SKNA measurement 3 months after ablation; both SKNA-Arm (p = 0.31) and SKNA-Chest (p = 0.27) were similar to those before ablation, respectively. Among patients with symptomatic drug-refractory paroxysmal AF receiving PVI, increased SKNA was observed 1 day after ablation and returned to the baseline 3 months after ablation. Elevation of SKNA was associated with lower early and late recurrences following ablation.

The comprehensive surveillance for interval changes in signal-averaged P-wave (SAPW) after pulmonary vein isolation (PVI) remains lacking. We aimed to analyze the SAPW parameters before and after PVI and explored their link to the left atrial electrical properties.Eighteen patients with paroxysmal atrial fibrillation receiving primary catheter ablation were enrolled. SAPW parameters, including root mean square voltages in the last 40, 30, and 20 ms (RMS40, RMS30, and RMS20, respectively), the total P-wave (RMSt), the integral of P-wave potentials (Int-p), and P-wave duration (fPWD), were measured before and after PVI and correlated to the left atrial activation time (LAT) and mean left atrial voltage (LAV) from electro-anatomical mapping.Compared with the SAPW before PVI, fPWD (before vs after PVI: 144.1 ± 5.2 vs 135.1 ± 11.9 ms, p = 0.02), Int-p (687.4 ± 173.1 vs 559 ± 202.5 mVms, p = 0.01), and RMSt (6.44 ± 1.3 vs 5.44 ± 2.0 mV, p = 0.04) all decreased after PVI. RMS20, RMS30, and RMS40 showed no significant difference. Similarly, LAT (97.5 ± 9.3 vs 90.5 ± 9.3 ms, p = 0.008) and LAV (1.37 ± 0.27 vs 0.96 ± 0.31 mV, p = 0.001) decreased after PVI. Although consistent changes after PVI were observed between SAPW parameters and LAT or LAV, no linear correlation was observed among them.The consistent changes in SAPW and left atrial electrical properties after PVI suggest that SAPW may be used as a noninvasive tool to monitor the responses to PVI.

The novel coronavirus disease 2019 (COVID-19), with first presentation of atypical pneumonia, has spread rapidly from Wuhan, China, on December 12, 2019 to over 200 countries, caused 2 310 572 infected individuals and 158 691 mortalities, updated on April 19, 2020. Many studies have published timely to help global healthcare workers to understand and control the disease. Vulnerable patients with risk factors such as elderly, cardiovascular diseases (eg, hypertension, coronary disease, or cardiomyopathy), diabetes, and chronic kidney disease have worse outcomes after COVID-19 infection. COVID-19 could directly cause cardiovascular injuries such as pericarditis, myocarditis, myocardial infarction, heart failure, arrhythmias, or thromboembolic events, which urge cardiologists to be involved in the frontline to practice. Here, we provide a review of COVID-19 on cardiovascular system to assist clinical cardiologists to better understand the disease and being capable of providing comprehensive medical support.

BACKGROUND: The presence of ventricular tachycardia (VT) is associated with higher mortality. The annual incidence of VT after a diagnosis of amyloidosis and the associated cardiovascular (CV) outcomes have not been well assessed in a large cohort. METHODS: A total of 12,139 amyloidosis patients were identified from the Taiwan National Health Insurance Research Database. Non-amyloidosis group was matched 1:1 for age, gender, hypertension, and diabetes mellitus (DM) to the amyloidosis group using a propensity score. Analysis of the risk of CV outcomes was conducted. We also analyzed the incidence of cardiac amyloidosis (CA). RESULTS: The incidence rates of amyloidosis and CA were 6.54 and 0.61 per 100,000 person-years, respectively. Multivariable analysis revealed that the risk of VT was higher in both the amyloidosis [hazard ratio (HR): 7.90; 95% confidence interval (CI): 4.49-13.9] and CA (HR: 153.3, 95% CI: 54.3-432.7) groups. In the amyloidosis group, the risk of heart failure (HF)-related hospitalization, CV death, and all-cause death was also higher. Amyloidosis was associated with a higher CV mortality rate following VT (HR: 1.50; 95% CI: 1.07-2.12). The onset of a new VT event in patients with amyloidosis was associated with HF, DM, chronic liver disease, and anti-arrhythmic drug use. CONCLUSIONS: In this nationwide cohort study, the incidence rates of amyloidosis and CA were 6.54 and 0.61 per 100,000 person-years, respectively. The long-term risks of VT and CV mortality were higher in the patients with amyloidosis and CA. The patients with amyloidosis had a poorer prognosis following VT events, highlighting the importance of continuous monitoring in these patients.

Background β-blockers may protect against catecholaminergic myocardial injury in critically ill patients. Long-term β-blocker users are known to have lower lactate concentrations and favorable sepsis outcomes. However, the effects of β1-selective and nonselective β-blockers on sepsis outcomes have not been compared. This study was conducted to investigate the impacts of different β-blocker classes on the mortality rate in septic patients. Methods We retrospectively screened 2678 patients admitted to the medical or surgical intensive care unit (ICU) between December 2015 and July 2017. Data from patients who met the Sepsis-3 criteria at ICU admission were included in the analysis. Premorbid β-blocker exposure was defined as the prescription of any β-blocker for at least 1 month. Bisoprolol, metoprolol, and atenolol were classified as β1-selective β-blockers, and others were classified as nonselective β-blockers. All patients were followed for 28 days or until death. Results Among 1262 septic patients, 209 (16.6%) patients were long-term β-blocker users. Patients with premorbid β-blocker exposure had lower heart rates, initial lactate concentrations, and ICU mortality. After adjustment for disease severity, comorbidities, blood pressure, heart rate, and laboratory data, reduced ICU mortality was associated with premorbid β1-selective [adjusted hazard ratio, 0.40; 95% confidence interval (CI), 0.18–0.92; P = 0.030], but not non-selective β-blocker use. Conclusion Premorbid β1-selective, but not non-selective, β-blocker use was associated with improved mortality in septic patients. This finding supports the protective effect of β1-selective β-blockers in septic patients. Prospective studies are needed to confirm it.

Background β blockers may protect against catecholaminergic myocardial injury in critically ill patients. Long-term β-blocker users are known to have lower lactate concentrations and favorable sepsis outcomes. However, the effects of cardioselective and nonselective β-blockers on sepsis outcomes have not been compared. This study was conducted to investigate the impacts of different β-blocker classes on the mortality rate in septic patients. Methods We retrospectively screened 2678 patients admitted to the medical or surgical intensive care unit (ICU) between December 2015 and July 2017. Data from patients who met the Sepsis-3 criteria at ICU admission were included in the analysis. Premorbid β-blocker exposure was defined as the prescription of any β-blocker for at least 1 month. Bisoprolol, metoprolol, and atenolol were classified as cardioselective β-blockers, and others were classified as nonselective β-blockers. All patients were followed for 28 days or until death. Results Among 1262 septic patients, 209 (16.6%) patients were long-term β-blocker users. Patients with premorbid β-blocker exposure had lower heart rates, initial lactate concentrations, and ICU mortality. After adjustment for disease severity, comorbidities, blood pressure, heart rate, and laboratory data, reduced ICU mortality was associated with premorbid cardioselective [adjusted hazard ratio (HR), 0.28; 95% confidence interval (CI), 0.11–0.74; P = 0.010], but not non-selective (adjusted HR, 0.78; 95% CI, 0.30–2.05; P = 0.611), β-blocker use. Conclusion Premorbid cardioselective, but not non-selective, β-blocker use was associated with improved mortality in septic patients. This finding supports the protective effect of cardioselective β-blockers in septic patients. Prospective studies are needed to confirm it.

Additional file 1: Supplemental Table. Numbers of study subjects with missing data.

BACKGROUND Atrial fibrillation (AF) is the most common cardiac arrhythmia, and increasing numbers of patients receive AF ablation nowadays. Therefore, in the cardiology division, residents need to be familiar with the AF ablation procedure-related knowledge for primary care. This study evaluated the baseline residents and patients' self-efficacy to the AF ablation procedure-related knowledge, developed the specific virtual reality (VR) informative aids, and evaluated the effects of VR training and resident-led VR aids-based patient education on their self-efficacy, in the aspects of familiarity, confidence and anxiety, and satisfaction. METHODS From 2019, April to 2020, April, this 1-year prospective prestudy and poststudy was undergone in the cardiology division. Between 2019, April and 2019, December, the experienced physicians were invited to develop VR informative aids for AF ablation procedure-related knowledge. Between January 2020 and April 2020, newly developed VR informative aids were implemented in the educational program of training rotated residents for giving patient education. RESULT A total of 20 residents and 32 patients were enrolled. The baseline self-reported self-efficacy and knowledge scores were relatively low among rotated residents and their patients. In addition to the high level of satisfaction, self-efficacy and knowledge scores of residents and their patients were increased after VR aids-based training and resident-led patient education. Higher degree of improvement in self-efficacy was noted among patients with depression/anxiety history than those without history. The follow-up assessments among residents showed that the positive effects of VR aids were sustained until 2 weeks later. CONCLUSION Overall, residents and patients reported that the VR aids increase the effectiveness of patient education, achieve the purpose of a paperless environment, and motivate them to recommend it to others. The implementation of resident-to-patient education has a positive impact on trainees and patients understanding about AF ablation procedures-related knowledge.

It is unclear whether diabetic angiopathy is related to oxidative stress-associated endothelial dysfunction. The authors investigated whether alteration of endothelin-1 and lipid peroxide production and activation of nuclear factor-κB expression were involved in lower limb amputation in type 2 diabetes mellitus patients.A total of 135 subjects including 51 type 2 diabetes mellitus patients with major lower extremity amputations and 36 diabetes mellitus patients without limb and vascular complication and 48 normal controls were recruited for this study. The authors measured the plasma soluble endothelin-1 concentrations by a sandwich enzyme immunoassay, and measured oxidative stress as determined by the lipid peroxide byproduct malondialdehyde. Histologic staining and nuclear factor-κB activation determined by electrophoretic mobility shift assay of the amputated vessels were examined.Histologic staining revealed that severe arteriosclerosis with atheroma formation in the amputated diabetic arteries was significantly prominent compared with normal controls. Soluble endothelin-1 concentrations and malondialdehyde levels were increased significantly in diabetic amputation patients compared with other groups (p0.001). The nuclear factor-κB binding activity in amputated diabetic stump vessels was more prominent compared with healthy vessels without diabetes mellitus. There was a positive correlation between endothelin-1 and malondialdehyde in patients with diabetic amputation (r = 0.46, p = 0.001).These results suggest that elevation of endothelin-1 and lipid peroxide levels is involved in the pathogenesis of diabetic foot amputation. An increase of lipid peroxide and endothelin-1 associated with nuclear factor-κB activation plays an important role in the development of diabetic angiopathies.

Objectives In patients with severe carotid artery stenosis, the anatomy of their Type III aortic arch increases the difficulty and complication rates during carotid artery stenting because of its tortuosity and sharp angulation for cannulation as well as the unstable support of the guidewire for shuttle sheath delivery. Methods We demonstrate a novel technique to overcome these challenges, namely the creation of stable innominate artery access by inserting a through-and-through body floss wire from the right brachial artery to the femoral artery. Results We successfully performed right carotid artery stenting in 3 patients with Type III arch anatomy. All patients received regular outpatient follow-up uneventfully for more than 1 year. Conclusions This facilitates the procedure of the right carotid artery stenting in patients with Type III aortic arch.

This paper describes a novel technique for multiple parameter extraction of the S12X TEM cell model using a fuzzy logic system (FLS). The FLS is utilized to capture the circuit information and to extract the circuit parameters based on experiential knowledge. The proposed extraction technique uses both linguistic information (i.e., human-like knowledge and experience) and numerical data of measurement to construct the fuzzy macromodel. The simulation results confirm the validity and estimation performance of the equivalent circuit by the advocated design methodology.

A fuzzy logic controller equipped with a training algorithm is developed such that the H∞ tracking performance should be satisfied for a model-free nonlinear multiple-input multiple-output (MIMO) system, with external disturbances. Due to universal approximation theorem, fuzzy control provides nonlinear controller, i.e., fuzzy logic controllers, to perform the unknown nonlinear control actions and the tracking error, because of the matching error and external disturbance is attenuated to arbitrary desired level by using H∞ tracking design technique. In this paper, a new direct adaptive interval type-2 fuzzy controller is developed to handle the training data corrupted by noise or rule uncertainties for nonlinear MIMO systems involving external disturbances. Therefore, linguistic fuzzy control rules can be directly incorporated into the controller and combine the H∞ attenuation technique. Simulation results show that the interval type-2 fuzzy logic system can handle unpredicted internal disturbance, data uncertainties, very well, but the adaptive type-1 fuzzy controller must spend more control effort in order to deal with noisy training data. Furthermore, the adaptive interval type-2 fuzzy controller can perform successful control and guarantee the global stability of the resulting closed-loop system and the tracking performance can be achieved.

This paper describes a novel technique for multiple parameter extraction of the S12X TEM cell model using a fuzzy logic system (FLS). The FLS is utilized to capture the circuit information and to extract the circuit parameters based on experiential knowledge. The proposed extraction technique uses both linguistic information (i.e., human-like knowledge and experience) and numerical data of measurement to construct the fuzzy macromodel. The simulation results confirm the validity and estimation performance of the equivalent circuit by the advocated design methodology.

The thorough electromagnetic compatibility (EMC) and signal integrity (SI) modeling of a complete system is a very challenging task due to the extreme complexity of high-speed applications. This paper describes a new methodology for the behavioral modeling based on radial basis function neural network (RBFNN). The stable and optimal learning rate, in the sense of maximum error reduction, for each iteration during the back propagation process can be found. The performance of the dynamic optimal learning rates (DOLR) for RBFNN is discussed by minimizing the mean square error (MSE) between actual and measured outputs for the set of neural network. From the experimental results, we can find that the proposed modeling approach enables to generate accurate behavioral model from measurement carried out on devices operating in their application environments.