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Background: Preoperative estimation of the volume of the left atrium (LA) and epicardial adipose tissue (EAT) on computed tomography (CT) images is associated with an increased risk of atrial fibrillation (AF) recurrence. We aimed to design a deep learning-based workflow to provide reliable automatic segmentation of the atria, pericardium, and EAT for future applications in the management of AF., Methods: This study enrolled 157 patients with AF who underwent first-time catheter ablation between January 2015 and December 2017 at Taipei Veterans General Hospital. Three-dimensional (3D) U-Net models of the LA, right atrium (RA), and pericardium were used to develop a pipeline for total, LA-EAT, and RA-EAT automatic segmentation. We defined fat within the pericardium as tissue with attenuation between -190 and -30 HU and quantified the total EAT. Regions between the dilated endocardial boundaries and endocardial walls of the LA or RA within the pericardium were used to detect voxels attributed to fat, thus estimating LA-EAT and RA-EAT., Results: The LA, RA, and pericardium segmentation models achieved Dice coefficients of 0.960 ± 0.010, 0.945 ± 0.013, and 0.967 ± 0.006, respectively. The 3D segmentation models correlated well with the ground truth for the LA, RA, and pericardium ( r = 0.99 and p < 0.001 for all). The Dice coefficients of our proposed method for EAT, LA-EAT, and RA-EAT were 0.870 ± 0.027, 0.846 ± 0.057, and 0.841 ± 0.071, respectively., Conclusion: Our proposed workflow for automatic LA, RA, and EAT segmentation using 3D U-Nets on CT images is reliable in patients with AF., Competing Interests: Conflicts of interest: Dr. Shih-Ann Chen, an editorial board member at Journal of the Chinese Medical Association , had no role in the peer review process of or decision to publish this article. The other authors declare that they have no conflicts of interest related to the subject matter or materials discussed in this article., (Copyright © 2024, the Chinese Medical Association.)

Background: The recent Atrial Fibrillation Management in Congestive Heart Failure With Ablation trial did not reveal any benefit of catheter ablation in patients with atrial fibrillation (AF), advanced heart failure (HF), and severely reduced left ventricular ejection fraction (LVEF). We hypothesized that radiofrequency catheter ablation (RFCA) could improve outcomes in HF patients with AF and impaired left ventricular systolic function (LVEF <50%) as compared with only medical therapy., Methods: We searched the literature for randomized clinical trials (RCTs) that compared RFCA to medical therapy in this population., Results: Compared with the medical therapy group, the RFCA group had significantly less all-cause mortality, HF hospitalization, and AF recurrence rates. The RFCA group had significantly higher peak oxygen consumption (VO 2max ), a better quality of life (Minnesota Living with Heart Failure Questionnaire score), and improved LVEF. However, RFCA for AF failed to reduce all-cause mortality in a specific meta-analysis of four RCTs that enrolled patients with LVEF ≤35%., Conclusion: Compared with medical therapy, RFCA for AF in the setting of HF with impaired systolic function is associated with better clinical (HF hospitalization and all-cause mortality), structural (LVEF improvement), functional (VO 2max ), and quality of life outcomes. However, RFCA for AF failed to reduce all-cause mortality in RCTs that enrolled patients with LVEF ≤35% and thereby indicated the necessary stratification to identify patients who may benefit more from RFCA., Competing Interests: Conflicts of interest: Dr. Shih-Ann Chen, an editorial board member at Journal of the Chinese Medical Association , had no role in the peer review process of or decision to publish this article. The other authors declare that they have no conflicts of interest related to the subject matter or materials discussed in this article., (Copyright © 2022, the Chinese Medical Association.)

Background: 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., Methods: 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., Results: 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., Conclusion: 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., Competing Interests: Conflicts of interest: Dr. Shih-Ann Chen, an editorial board member at Journal of the Chinese Medical Association, had no role in the peer review process of or decision to publish this article. The other authors declare that they have no conflicts of interest related to the subject matter or materials discussed in this article., (Copyright © 2022, the Chinese Medical Association.)

Background: The application of new imaging software for the reconstruction of left atrium (LA) geometry during atrial fibrillation (AF) ablation has not been well investigated., Methods: A total of 27 patients undergoing AF ablation using a CARTO Segmentation Module system were studied (phase I). High-density LA mapping using PentaRay was merged with computed tomography-based geometry from the auto-segmentation module. The spatial distortion between the two LA geometries was analyzed and compared using Registration Match View. The associated contact force on the two LA shells was prospectively validated in 16 AF patients (phase II)., Results: Of the five LA regions, the roof area had the highest quality score between the two LA shells (1.7 ± 0.6). In addition, among the pulmonary veins (PVs), higher quality scores were observed in bilateral PV carinas (both 1.8 ± 0.1, p < 0.05) than in the anterior or posterior PV regions. Furthermore, surrounding the PV ostium, the on-surface points had a significantly higher contact force when targeting the high-density fast anatomical mapping shell than for the auto-segmentation module (right superior pulmonary vein, 20.7 ± 5.8 g vs 12.5 ± 4.4 g; right inferior pulmonary vein, 19.3 ± 6.8 g vs 11.8 ± 4.8 g; left superior pulmonary vein, 22.5 ± 7.3 g vs 11.2 ± 4.5 g; left inferior pulmonary vein, 15.7 ± 6.9 g vs 9.7 ± 4.4 g, p < 0.05 for each group)., Conclusion: The CARTO Segmentation Module and Registration Match View provide better anatomic accuracy and less regional distortion of the LA geometry, and this can prevent excessive contact and potential procedural complications.

Background: Pulmonary embolism (PE) is frequently associated with cancer. This study aimed to assess patients with acute PE and identify diagnostic predictors of new cancer after 1 year of follow-up., Methods: One hundred and twenty-one patients with PE were enrolled consecutively from the emergency department of a single medical center in Taiwan. Data from computed tomography angiography, echocardiogram, electrocardiogram and for baseline comorbidities, clinical presentation, and laboratory parameters were recorded. The surviving discharged patients without a cancer diagnosis were followed-up for 1 year, and new malignancies were recorded., Results: Of 121 patients with acute PE, 44 (36%) had an underlying cancer history (cancer group), and 77 (64%) did not (noncancer group). Baseline demographic characteristics, comorbidities, clinical symptoms, biochemical parameters, echocardiogram data, and electrocardiogram data of the two groups were similar except for a higher hospital mortality rate (56.8% vs 9.1%; p < 0.001), lower body mass index (22.6 ± 4.1 vs 25.5 ± 4.9; p =0.02), higher systolic blood pressure (139.7 ± 33.7 vs 125.4 ± 24.1; p = 0.02), lower low-density lipoprotein level (67.4 ± 38.3 vs 90.4 ± 33.8; p = 0.04), lower creatinine kinase (CK; 43.0 ± 43.0 vs 83.5 ± 83.1; p = 0.01), higher myocardial band (MB) form of CK ratio (0.2 ± 0.2 vs 0.1 ± 0.1; p < 0.01), higher partial pressure of arterial oxygen (122.81 ± 81.2 vs 90.2 ± 59.4; p = 0.03), and less presentation of chest pain (15.9% vs 40.3%; p = 0.01) in the cancer group. Kaplan-Meier curve analysis revealed that the 30-day survival rate was higher in the noncancer group than in the cancer group (log-rank p = 0.04). After 1 year of follow-up, 6 of 59 (10.17%) initial non-cancer-related PE survivors were diagnosed with malignancies. After multivariate analysis, only the initial CK-MB level was associated with a diagnosis of new cancer (hazard ratio [HR]: 1.37, 95% confidence interval [CI]: 1.029-1.811; p = 0.03)., Conclusion: This study suggests that the CK-MB level is associated with future malignancy in patients with PE. Patients with cancer-related PE had a worse 30-day survival rate.

Catheter ablation provides a therapeutic option for decreasing episodes of ventricular tachycardia in patients with coronary artery disease. Clinical studies show improvement with catheter ablation in reducing arrhythmia recurrence and therapy from implantable defibrillators, but not in decreasing mortality. Ablation can be an important tool for patients with electrical storm. Overall, complication rates of catheter ablation are acceptable, but recurrence rates are still significant. Advances in mapping and ablation technologies could be expected to improve the success rates and reduce the mortality.

Background: For patients with atrial fibrillation (AF) receiving cardiac implantable electronic device (CIED) implantations, current consensus recommends uninterrupted non-vitamin K antagonist oral anticoagulant (NOAC) considering low incidence of bleeding or thrombo-embolic events. It remains unknown whether uninterrupted strategy outweighs discontinuation method for patients receiving NOAC., Methods: From January 1, 2013 to June 1, 2017, we enrolled 100 patients (mean age 78.3 ± 10.2 years, 58% male) with AF taking NOAC for stroke prevention eligible for CIED implantation in a tertiary medical center, Taipei, Taiwan. NOAC was continued without skipping any doses during the surgery. The baseline characteristics, underlying diseases, CHA2DS2-VASc score, and clinical course of every patient were reviewed and analyzed., Results: Among these patients, 28 were on dabigatran, 61 on rivaroxaban, 10 on apixaban, and one on edoxaban, respectively. There were no adverse events except one case of pericardial effusion and another one with large pocket hematoma. One patient receiving implantable cardioverter defibrillator implantation had late onset of pericardial effusion with impending tamponade necessitating pericardiocentesis. Another patient had large pocket hematoma, which spontaneously resolved within 1 month without further intervention. No periprocedural mortality and stroke occurred., Conclusion: Uninterrupted NOAC during CIED implantations may be an acceptable option especially in patients with high risk for thromboembolism. However, special caution should be paid during defibrillator implantation considering relatively higher risk of bleeding, perhaps due to the larger size of the defibrillator lead.

Background: Bilirubin is associated with different cardiovascular diseases. The relationship between bilirubin and atrial fibrillation (AF) remains unclear. The aim of this study is to determine the association between bilirubin and AF recurrence after catheter ablation., Methods: A total of 212 patients who received AF ablation were retrospectively studied. The total bilirubin level, clinical characteristics, and echocardiographic findings were analyzed to predict the outcome of AF ablations., Results: During a mean follow-up period of 12.2 ± 5.8 months, 61 (28.8%) patients had AF recurrence after catheter ablation. The patients with AF recurrence had a larger left atrial (LA) diameter (39.8 ± 6.3 versus 36.7 ± 5.8 mm; p = 0.001) and higher total bilirubin levels (0.82 ± 0.37 versus 0.63 ± 0.29 mg/dL; p < 0.001) than those without recurrence. The patients with recurrence had higher direct and indirect bilirubin levels than patients without recurrence. The total bilirubin level remained an independent predictor of AF recurrence after multivariate analysis (odds ratio, 4.95; 95% CI, 1.65-14.83; p = 0.004). We identified a cut point of the total bilirubin level for predicting AF recurrence by receiver operator characteristic curve (cut point, 0.7 mg/dL; area under the curve, 0.65; p < 0.001). The total bilirubin levels were positively correlated with the neutrophil counts. However, there were no associations among the total bilirubin level, left atrial (LA) diameter, and voltage., Conclusion: Higher serum bilirubin levels were associated with AF recurrence in paroxysmal AF patients following catheter ablation.

Background: It is unclear whether atrial fibrillation (AF) adversely influences the clinical course of patients with hepatocellular carcinoma (HCC)., Methods: During the period from January 1, 2001 to December 31, 2010, 476 patients (mean ± SD age 60.3 ± 12.9 years) diagnosed with HCC were retrospectively enrolled in our study. The HCC stage, treatment, baseline characteristics, underlying cardiovascular diseases, and corresponding drug treatment were systematically reviewed. The primary endpoint was death from any cause., Results: AF was associated with a significantly reduced survival time in patients with HCC (AF vs. non-AF patients mean ± SD survival time 470.1 ± 89.6 days vs. 1161.2 ± 32.6 days, log-rank p < 0.001; probability of survival 0.20, 95% confidence interval 0.10-0.38, p < 0.001). After adjustment for sex and age, AF was still associated with poorer survival times (hazard ratio 4.131, 95% confidence interval 2.134-5.733, p < 0.001). The causes of death among 22 patients with both HCC and AF included 11 cases of hepatic failure, four cases of ruptured tumor, and two cases of bleeding from esophageal varices. None of these patients with AF used warfarin. Seven bleeding events related to HCC were noted, but none of these patients developed a major thromboembolism. The mean ± SD follow-up period was 645 ± 468 days., Conclusion: Patients with HCC had a significantly reduced survival time with the comorbidity of AF. Tumor rupture was relatively common among patients with both HCC and AF. The anticoagulation treatment of AF in patients with HCC deviated from the current guidelines without an increase in thromboembolic events., (Copyright © 2013. Published by Elsevier B.V.)

Atrial fibrillation (AF) maintenance is promoted by an atrial substrate that is suitable for the initiation and continuation of the re-entering wavelets. During the first week of AF, the atrial substrate is modified by electrical remodeling, with shortening of the atrial refractoriness and slowing of the conduction velocity. Structural remodeling is the so-called "second factor" that facilitates the maintenance of AF in the following months. The ultrastructural changes result in an inhomogeneous conduction and electrical uncoupling, and the enlarged atrium is able to accommodate more circulating wave fronts that stabilize the AF. Reversal of the electrical remodeling develops within 1 week after the restoration of AF to sinus rhythm. However, reverse structural remodeling develops more slowly and may be just partially reversible. The substrate properties during AF recurrences after undergoing catheter ablation are more complex and need to be clarified in future studies.