Background: Cardiac resynchronization therapy (CRT) is an effective treatment option for patients with heart failure (HF) and left ventricular (LV) dyssynchrony. However, the problem of some patients not responding to CRT remains unresolved. This study aimed to propose a novel in silico method for CRT simulation. Methods: Three-dimensional heart geometry was constructed from computed tomography images. The finite ele‑ ment method was used to elucidate the electric wave propagation in the heart. The electric excitation and mechani‑ cal contraction were coupled with vascular hemodynamics by the lumped parameter model. The model parameters for three-dimensional (3D) heart and vascular mechanics were estimated by matching computed variables with measured physiological parameters. CRT effects were simulated in a patient with HF and left bundle branch block (LBBB). LV end-diastolic (LVEDV) and end-systolic volumes (LVESV), LV ejection fraction (LVEF), and CRT responsiveness measured from the in silico simulation model were compared with those from clinical observation. A CRT responder was defined as absolute increase in LVEF ≥ 5% or relative increase in LVEF ≥ 15%. Results: A 68-year-old female with nonischemic HF and LBBB was retrospectively included. The in silico CRT simu‑ lation modeling revealed that changes in LVEDV, LVESV, and LVEF by CRT were from 174 to 173 mL, 116 to 104 mL, and 33 to 40%, respectively. Absolute and relative ΔLVEF were 7% and 18%, respectively, signifying a CRT responder.In clinical observation, echocardiography showed that changes in LVEDV, LVESV, and LVEF by CRT were from 162 to 119 mL, 114 to 69 mL, and 29 to 42%, respectively. Absolute and relative ΔLVESV were 13% and 31%, respectively, also signifying a CRT responder. CRT responsiveness from the in silico CRT simulation model was concordant with that in the clinical observation. Conclusion This in silico CRT simulation method is a feasible technique to screen for CRT non-responders in patients with HF and LBBB.

Background: Conventional modality requires several days observation by Holter monitor to differentiate atrial fibril‑ lation (AF) between Paroxysmal atrial fibrillation (PAF) and Non-paroxysmal atrial fibrillation (Non-PAF). Rapid and practical differentiating approach is needed. Objective: To develop a machine learning model that observes 10-s of standard 12-lead electrocardiograph (ECG) for real-time classification of AF between PAF versus Non-PAF. Methods: In this multicenter, retrospective cohort study, the model training and cross-validation was performed on a dataset consisting of 741 patients enrolled from Severance Hospital, South Korea. For cross-institutional validation, the trained model was applied to an independent data set of 600 patients enrolled from Ewha University Hospital, South Korea. Lasso regression was applied to develop the model. Results: In the primary analysis, the Area Under the Receiver Operating Characteristic Curve (AUC) on the test set for the model that predicted AF subtype only using ECG was 0.72 (95% CI 0.65–0.80). In the secondary analysis, AUC only using baseline characteristics was 0.53 (95% CI 0.45–0.61), while the model that employed both baseline characteris‑ tics and ECG parameters was 0.72 (95% CI 0.65–0.80). Moreover, the model that incorporated baseline characteristics, ECG, and Echocardiographic parameters achieved an AUC of 0.76 (95% CI 0.678–0.855) on the test set. Conclusions Our machine learning model using ECG has potential for automatic differentiation of AF between PAF versus Non-PAF achieving high accuracy. The inclusion of  Echocardiographic parameters further increases model per‑ formance. Further studies are needed to clarify the next steps towards clinical translation of the proposed algorithm.

Purpose: This study aimed to examine the effects of self-efficacy, social support, self-esteem, and depressive symptoms on physical activity in midlife and old-aged women with depression. Methods: Midlife and old women (N=83) diagnosed with depression were recruited from the psychiatry outpatient clinic in Seoul. Data were collected via self-report measures, and they were analyzed using descriptive statistics, Pearson correlation coefficients, and hierarchical multiple linear regression. Results: Physical activity had significant positive correlations with self-efficacy, social support, and self-esteem, and it had a significant negative correlation with depressive symptoms. In the hierarchical multiple regression model of physical activity (adjusted R2=.34, p=.003), self-efficacy (β=.47, p<.001) and depressive symptoms (β=-.42, p=.003) were statistically significant. Conclusion Self-efficacy and depressive symptoms are important factors influencing physical activity in midlife and old women with depression. To improve the physical activity of this population, nursing interventions should aim to promote self-efficacy and alleviate depressive symptoms.

Background and Objectives: Cavotricuspid isthmus (CTI) block is easily achieved, and prophylactic ablation can be performed during atrial fibrillation (AF) ablation. However, the previous study was too small and short-term to clarify the efficacy of this block. Methods: Patients who underwent catheter ablation for paroxysmal AF were enrolled, and patients who had previous or induced atrial flutter (AFL) were excluded. We randomly assigned 366 patients to pulmonary vein isolation (PVI) only and prophylactic CTI ablation (PVI vs. PVI+CTI). Results: There was no significant difference in procedure time between the two groups because most CTI blocks were performed during the waiting time after the PVI (176.8±72.6 minutes in PVI vs. 174.2±76.5 minutes in PVI+CTI, p=0.75). All patients were followed up for at least 18 months, and the median follow-up was 3.4 years. The recurrence rate of AF or AFL was not different in the 2 groups (25.7% in PVI vs. 25.7% in PVI+CTI, p=0.92). The recurrence rate of any AFL was not significantly different in the 2 groups (3.3% in PVI vs. 1.6% in PVI+CTI, p=0.31). The recurrence rate of typical AFL also was not different (0.5% in PVI vs. 0.5% in PVI+CTI, p=0.99). Conclusions In this large and long-term follow-up study, prophylactic CTI ablation had no benefit in patients with paroxysmal AF without typical AFL.

Optimized management of atrial fibrillation requires patient-oriented decision making with a multidisciplinary approach. This report incorporates recent authoritative studies to provide detailed recommendations for managing atrial fibrillation in specific clinical settings. The principles of the Atrial fibrillation Better Care (ABC) pathway apply in these clinical settings. In addition, specific considerations are discussed for each of these conditions and populations.

Optimized management of atrial fibrillation requires patient-oriented decision making with a multidisciplinary approach. This report incorporates recent authoritative studies to provide detailed recommendations for managing atrial fibrillation in specific clinical settings. The principles of the Atrial fibrillation Better Care (ABC) pathway apply in these clinical settings. In addition, specific considerations are discussed for each of these conditions and populations.

Background and Objectives: Cavotricuspid isthmus (CTI) block is easily achieved, and prophylactic ablation can be performed during atrial fibrillation (AF) ablation. However, the previous study was too small and short-term to clarify the efficacy of this block. Methods: Patients who underwent catheter ablation for paroxysmal AF were enrolled, and patients who had previous or induced atrial flutter (AFL) were excluded. We randomly assigned 366 patients to pulmonary vein isolation (PVI) only and prophylactic CTI ablation (PVI vs. PVI+CTI). Results: There was no significant difference in procedure time between the two groups because most CTI blocks were performed during the waiting time after the PVI (176.8±72.6 minutes in PVI vs. 174.2±76.5 minutes in PVI+CTI, p=0.75). All patients were followed up for at least 18 months, and the median follow-up was 3.4 years. The recurrence rate of AF or AFL was not different in the 2 groups (25.7% in PVI vs. 25.7% in PVI+CTI, p=0.92). The recurrence rate of any AFL was not significantly different in the 2 groups (3.3% in PVI vs. 1.6% in PVI+CTI, p=0.31). The recurrence rate of typical AFL also was not different (0.5% in PVI vs. 0.5% in PVI+CTI, p=0.99). Conclusions In this large and long-term follow-up study, prophylactic CTI ablation had no benefit in patients with paroxysmal AF without typical AFL.

BACKGROUND AND OBJECTIVES: Nationwide social inequalities of oral anticoagulation (OAC) usage after the introduction of non-vitamin K antagonist oral anticoagulants (NOACs) have not been well identified in patients with atrial fibrillation (AF). This study assessed overall rate and social inequalities of OAC usage after the introduction of NOAC in Korea.METHODS: Between January 2002 and December 2016, we identified 888,540 patients with AF in the Korea National Health Insurance system database. The change of OAC rate in different medical systems after the introduction of NOAC were evaluated.RESULTS: In all population, overall OAC use increased from 13.2% to 23.4% (p for trend <0.001), and NOAC use increased from 0% to 14.6% (p for trend <0.001). Compared with pre-reimbursement (0.48%), the annual increase of OAC use was significantly higher after partial (1.16%, p<0.001), and full reimbursement of OAC (3.72%, p<0.001). Full reimbursement of NOAC (adjusted odds ratio, 2.10; 95% confidence interval, 2.04–2.15) was independently associated with higher OAC use. However, the difference of overall OAC usage between tertiary referral hospitals and nursing or public health centers increased from 17.9% in 2010 to 36.8% in 2016. Moreover, usage rate of NOAC was significantly different among different medical systems from 37.2% at the tertiary referral hospital and 5.5% at nursing or public health centers.CONCLUSIONS: Introduction of NOACs in routine practice for stroke prevention in AF was associated with improved rates of overall OAC use. However, significant practice-level variations in OAC and NOAC use remain producing social inequalities of OAC despite full reimbursement.
Anticoagulants ; Atrial Fibrillation ; Humans ; Insurance ; Korea ; National Health Programs ; Nursing ; Odds Ratio ; Public Health ; Socioeconomic Factors ; Stroke ; Tertiary Care Centers

BACKGROUND AND OBJECTIVES: The objective of this study was to evaluate the long-term clinical outcomes and the incidence of permanent pacemaker implantation after catheter ablation in patients with of atrial fibrillation (AF) and sinus node dysfunction (SND).METHODS: Among 3,068 total consecutive patients who underwent AF catheter ablation (AFCA), this study included 222 (9.5%; men 53.2%, 63.7±9.2 years of age, 81.5% paroxysmal AF) with underlying SND and a regular rhythm follow-up. We analyzed the rhythm outcomes, changes in the mean heart rate or heart rate variability, and permanent pacemaker implantation rate.RESULTS: During 47.5±28.8 months of follow-up, 25 (11.3%) patients received pacemaker implantations due to symptomatic SND. More than half (56.0%, 14/25) underwent a pacemaker implantation within 3 months of the AFCA, and the annual pacemaker implantation rate was 2.0% afterwards. Both the early (68.0% vs. 31.0%, p<0.001) and clinical AF recurrence (68.0% vs. 32.5%, p=0.001) rates and continuous antiarrhythmic drug use after 3 months (44.0% vs. 24.4%, p=0.036) were significantly higher in patients requiring pacemaker implantations than those that did not. An anterior linear ablation (odds ratio [OR], 9.37 [3.03–28.9]; p<0.001) and the E/Em (OR, 1.15 [1.02–1.28]; p=0.018) were independently associated with permanent pacemaker implantations after AFCA in patients with AF and SND.CONCLUSIONS: After AFCA in patients with AF and SND, 1 of 9 patients needed a pacemaker implantation and half needed implantations within 3 months. The AF recurrence rate was significantly higher in those who required pacemaker implantations after the AFCA.
Atrial Fibrillation ; Catheter Ablation ; Catheters ; Follow-Up Studies ; Heart Rate ; Humans ; Incidence ; Male ; Pacemaker, Artificial ; Recurrence ; Sick Sinus Syndrome ; Sinoatrial Node

BACKGROUND AND OBJECTIVES: The objective of this study was to evaluate the long-term clinical outcomes and the incidence of permanent pacemaker implantation after catheter ablation in patients with of atrial fibrillation (AF) and sinus node dysfunction (SND). METHODS: Among 3,068 total consecutive patients who underwent AF catheter ablation (AFCA), this study included 222 (9.5%; men 53.2%, 63.7±9.2 years of age, 81.5% paroxysmal AF) with underlying SND and a regular rhythm follow-up. We analyzed the rhythm outcomes, changes in the mean heart rate or heart rate variability, and permanent pacemaker implantation rate. RESULTS: During 47.5±28.8 months of follow-up, 25 (11.3%) patients received pacemaker implantations due to symptomatic SND. More than half (56.0%, 14/25) underwent a pacemaker implantation within 3 months of the AFCA, and the annual pacemaker implantation rate was 2.0% afterwards. Both the early (68.0% vs. 31.0%, p<0.001) and clinical AF recurrence (68.0% vs. 32.5%, p=0.001) rates and continuous antiarrhythmic drug use after 3 months (44.0% vs. 24.4%, p=0.036) were significantly higher in patients requiring pacemaker implantations than those that did not. An anterior linear ablation (odds ratio [OR], 9.37 [3.03–28.9]; p<0.001) and the E/Em (OR, 1.15 [1.02–1.28]; p=0.018) were independently associated with permanent pacemaker implantations after AFCA in patients with AF and SND. CONCLUSIONS After AFCA in patients with AF and SND, 1 of 9 patients needed a pacemaker implantation and half needed implantations within 3 months. The AF recurrence rate was significantly higher in those who required pacemaker implantations after the AFCA.