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Hypertension is an independent risk factor for thromboembolic events in patients with atrial fibrillation (AF). However, the association between blood pressure (BP) control and thromboembolic events remains under-evaluated in patients with AF. We aimed to identify the relation between BP control and the risk of ischemic stroke and systemic embolism in hypertensive patients with AF. Data on 13,712 consecutive patients with AF (9,505 with and 4,207 without hypertension) were retrospectively analyzed. The hypertensive group was divided into quartiles according to the initial BP, linearly interpolated mean BP, variability independent of the mean of the BP, and time in therapeutic range (lt;130 mm Hg for systolic BP [SBP] andlt;80 mm Hg for diastolic BP) during follow-up. The primary outcome was ischemic stroke and systemic embolism. The mean follow-up duration of the study population was median 2.7 years (interquartile range 1.1 to 4.9 years), and the median number of BP measurements was 14 (interquartile range 6 to 25) times. Strictly controlled initial and interpolated mean BP and low variability in controlled BP (variability independent of the mean) were associated with a lower risk of ischemic stroke and systemic embolism for both SBP and diastolic BP. A similar risk was observed in patients with strictly controlled SBP (time in therapeutic range under 130 mm Hggt;94%) and those without hypertension. In conclusion, continuous and strict maintenance of SBP under 130 mm Hg with low variability at outpatient clinic follow-up reduces the risk of ischemic stroke and systemic embolism in patients with hypertension and AF.

Background The clinical benefits and risks of anticoagulation therapy in patients with chronic kidney disease (CKD) are still inconclusive. We describe the outcomes of patients with atrial fibrillation (AF) after anticoagulation therapy according to differences in creatinine clearance (CrCl). We also aimed to determine the patients who could benefit from anticoagulation therapy. Methods This is a retrospective observational review of patients with AF who were managed at Asan Medical Center (Seoul, Korea) between January 1, 2006, and December 31, 2018. Patients were categorized into groups according to their baseline CrCl by Cockcroft–Gault equation and their outcomes were evaluated (CKD 1, ≥ 90 mL/min; CKD2, 60–89 mL/min; CKD3, 30–59 mL/min; CKD4, 15–29 mL/min; CKD 5, Results We identified 12,714 consecutive patients with AF (mean 64.6 ± 11.9 years, 65.3% male, mean CHA2DS2-VASc score 2.4 ± 1.6 points) between 2006 and 2017. In patients receiving anticoagulation therapy (n = 4447, 35.0%), warfarin (N = 3768, 84.7%) was used more frequently than NOACs (N = 673, 15.3%). There was a higher 3-year rate of NACE with renal function deterioration (14.8%, 18.6%, 30.3%, 44.0%, and 48.8% for CKD stages 1–5, respectively).The clinical benefit of anticoagulation therapy was most prominent in patients with CKD 1 (hazard ratio [HR] 0.49, 95% confidence interval [CI] 0.37–0.67), 2 (HR 0.64 CI 0.54–0.76), and 3 (HR 0.64 CI 0.54–0.76), but not in CKD 4 (HR 0.86, CI 0.57–1.28) and 5 (HR 0.81, CI 0.47–1.40). Among patients with CKD, the benefit of anticoagulation therapy was only evident in those with a high risk of embolism (CHA2DS2-VASc score ≥ 4, HR 0.25, CI 0.08–0.80). Conclusion Advanced CKD is associated with a higher risk of NACE. The clinical benefit of anticoagulation therapy was reduced with the increasing CKD stage.

Background Evidence and guidelines for Non-vitamin K antagonist oral anticoagulants (NOACs) use when prescribing concurrent rifampin for tuberculosis treatment in patients with non-valvular atrial fibrillation (NVAF) are limited. Methods Using the Korean National Health Insurance Service database from January 2009 to December 2018, we performed a population-based retrospective cohort study to assess the net adverse clinical events (NACE), a composite of ischemic stroke or systemic embolism and major bleeding, of NOACs compared with warfarin among NVAF patients taking concurrent rifampin administration for tuberculosis treatment. After a propensity matching score (PSM) analysis, Cox proportional hazards regression was performed in matched cohorts to investigate the clinical outcomes. Results Of the 735 consecutive patients selected, 465 (63.3%) received warfarin and 270 (36.7%) received NOACs. Among 254 pairs of patients after PSM, the crude incidence rate of NACE was 25.6 in NOAC group and 32.8 per 100 person-years in warfarin group. There was no significant difference between NOAC and warfarin use in NACE (hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.48–1.14; P = 0.172). Major bleeding was the main driver of NACE, and NOAC use was associated with a statistically significantly lower risk of major bleeding than that with warfarin use (HR, 0.63; 95% CI, 0.40–1.00; P = 0.0499). Conclusions In our population-based study, there was no statically significant difference in the occurrence of NACE between NOAC and warfarin use. NOAC use may be associated with a lower risk of major bleeding than that with warfarin use.

Pulmonary vein isolation is an well-established treatment strategy for atrial fibrillation (AF), and it is especially effective for patients with paroxysmal AF. However, the success rate is limited for patients with persistent AF, because non-pulmonary vein triggers which increase AF recurrence are frequently found in these patients. The major non-pulmonary vein triggers are from the left atrial posterior wall, left atrial appendage, ligament of Marshall, coronary sinus, superior vena cava, and crista terminalis, but other atrial sites can also generate AF triggers. All these sites have been known to contain atrial myocytes with potential arrhythmogenic electrical activity. The prevalence and clinical characteristics of these non-pulmonary vein triggers are well studied; however, the clinical outcome of catheter ablation for persistent AF is still unclear. Here, we reviewed the current ablation strategies for persistent AF and the clinical implications of major non-pulmonary vein triggers.

Background: We aimed to elucidate the effects of anticoagulation therapy in patients with atrial fibrillation (AF) according to the difference in renal function and define a chronic kidney disease (CKD) population that could benefit from anticoagulation therapy. Methods: Using datasets from the Asan Biomedical Research Environment Database between 2006 and 2017, 12,641 patients with nonvalvular AF were analyzed. The primary outcome was the net clinical outcome, defined as a composite of all-cause mortality, thromboembolic events, and major bleeding. Results: Patients were categorized into groups according to their baseline creatinine clearance. There was a trend for a progressive increase in the prevalence of stroke or systemic embolism, major bleeding, and all-cause mortality as the renal function deteriorated. The clinical benefit of anticoagulation therapy was the most prominent in patients with normal renal function and was reduced in those with advanced-stage CKD. Among CKD 5 patients, the benefit of anticoagulation therapy was only evident in those with a very high risk of embolism (CHA2DS2-VASc score ≥4). Conclusion: Advanced CKD is associated with a higher risk of the net clinical outcome. The clinical benefit of anticoagulation therapy reduces with the increasing degree of CKD. In CKD5, anticoagulation should be considered in high risk of embolism.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been shown to lower cardiovascular morbidity and mortality in patients with type 2 diabetes mellitus (T2DM) and high cardiovascular risks. Here, we aimed to evaluate the effect of SGLT2 inhibitors on major adverse cardiovascular events (MACE), a composite of cardiovascular mortality, myocardial infarction, or ischemic stroke and hospitalization for heart failure in patients with T2DM and atrial fibrillation (AF). Using the Korean National Health Insurance Service database, we identified 40,268 patients with T2DM and AF who were newly prescribed oral hypoglycemic drugs (2,977 patients with SGLT2 inhibitors and 37,291 patients without SGLT2 inhibitors) between 2014 and 2018. After 1: 4 propensity score matching, patients who received SGLT2 inhibitors (n = 2,958) and those who did not receive SGLT2 inhibitors (n = 10,691) were enrolled, and followed up until December 31, 2018. During a mean follow-up duration of 2.1 ± 1.4 years, the risk of major adverse cardiovascular events was similar between the 2 groups (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.76 to 1.21). There were no significant differences between the 2 groups for cardiovascular mortality, myocardial infarction, or ischemic stroke. However, patients who received SGLT2 inhibitors had significantly lower risks of hospitalization for heart failure (HR 0.70, 95% CI 0.53 to 0.93) and all-cause mortality (HR 0.74, 95% CI 0.56 to 0.98) than those who did not receive SGLT2 inhibitors. In conclusion, in this real-world cohort of Asian patients with T2DM and AF, use of SGLT2 inhibitors was associated with a lower risk of hospitalization for heart failure.

Background: In the treatment of type 2 diabetes mellitus (T2DM) in atrial fibrillation (AF) patients, evidence of the comparative effectiveness of sodium-glucose cotransporter 2 (SGLT2) inhibitors vs the other hypoglycemic drugs on cardiovascular morbidity and mortality is lacking. This study aimed to evaluate the comparative effectiveness of SGLT2 inhibitors vs the other hypoglycemic drugs on major adverse cardiovascular events and heart failure for hospitalization in patients with T2DM and AF.Methods: A cohort study used data from the Korean National Health Insurance Service database compared the use of SGLT2 inhibitors vs the other hypoglycemic drugs for treatment of T2DM in AF patients. We identified 40,268 patients with T2DM and AF who were newly prescribed oral hypoglycemic drugs (2,977 individualst with SGLT2 inhibitors and 37,291 individuals without SGLT2 inhibitors) between 2014 and 2018. After 1:4 propensity score matching, patients who received SGLT2 inhibitors (n=2,958) and those who did not receive SGLT2 inhibitors (n=10,691) were enrolled, and followed up until December 31, 2018. The primary study outcome was major adverse cardiovascular events (MACE), a composite of cardiovascular mortality, myocardial infarction, or ischemic stroke. Secondary outcoms were hospitalization for heart failure and all-cause mortality. The risks of study outcomes were assessed using a Cox proportional hazard model.Results: Mean age of all participants was 59.7 ± 11.9 years and 8.023 [58%] were male. During a mean follow-up duration of 2.1 ± 1.4 years, SGLT2 inhibitors were not significantly associated with reduced risk of MACE(hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.76-1.21) compared with the other hypoglycemic drugs. However, patients who received SGLT2 inhibitors had significantly lower risks of hospitalization for heart failure (HR, 0.70; 95% CI, 0.53-0.93) and all-cause mortality (HR, 0.74; 95% CI, 0.56-0.98) than those who did not receive SGLT2 inhibitors. Conclusions: In this real-world cohort of Asian patients with T2DM and AF, new use of SGLT2 inhibitors was associated with a lower risk of hospitalization for heart failure compared with use of the other hypoglycemic drugs.

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. Trial registration ClinicalTrials.gov Identifier: NCT02031705.

Background This study investigated 12-lead electrocardiogram (ECG) predictors associated with atrial fibrillation (AF) or flutter (AFL), specifically whether ventricular repolarization abnormalities in surface ECG (i.e., non-specific ST-T abnormalities [NSSTTA], QT prolongation, early repolarization [ER]) were associated with the development of AF or AFL.Methods and Results:This study included 16,793 ambulatory Koreans (mean age 48.2 years, 62.3% male) who underwent medical check-ups at Asan Medical Center in 2002 (NSSTTA, n=1,037 [6.2%]; ER, n=1,493 [8.9%]). The primary outcome was the incidence of ECG-documented AF or AFL. During follow-up, new-onset AF or AFL was documented in 334 subjects (2.0%). The incidence of AF or AFL at the 10-year follow-up was higher in patients with than without NSSTTA (3.5% vs. 1.6%; hazard ratio [HR] 1.79, 95% confidence interval [CI] 1.28-2.50). The QT interval was associated with a higher risk of AF or AFL (HR 1.12 [95% CI 1.07-1.17] per 10 ms), and the risk was even higher in patients with multiple-region NSSTTA (HR 2.30; 95% CI 1.64-3.21) and NSSTTA with QT prolongation (HR 4.06; 95% CI 2.14-7.69). ER was not associated with a higher risk of AF or AFL (HR 1.02; 95% CI 0.71-1.46). Conclusions NSSTTA and QT prolongation, but not ER, were associated with a higher risk of future AF or AFL in a general ambulatory population after adjusting for parameters of atrial depolarization.

Background Studies have shown that the concomitant use of a vitamin K antagonist (VKA) and an antiplatelet (APL) drug increased the bleeding risk and was less effective at preventing ischemic events. This study aimed to investigate the control status of international normalized ratio (INR) and the discontinuation rate of a VKA in patients taking VKA plus an APL drug compared with those taking a VKA alone. Methods Data were extracted from the KORean Atrial Fibrillation Investigation II registry, a multicenter noninterventional prospective observational study. Nonvalvular atrial fibrillation (NVAF) patients with CHADS 2 scores ≥ 1 who newly started (within 3 months) a VKA were enrolled and followed up for 1 year. Results A total of 866 NVAF patients (mean age, 67.7 years; 60.3% men) without a bleeding history were divided into the VKA+APL (n = 229) and VKA alone (n = 637) groups. During follow‐up, mean INR level was lower in the VKA+APL group than in the VKA alone group (1.7 ± 0.8 vs 1.9 ± 0.9, P = 0.0005). INR levels were poorly controlled in both groups (66.1% and 64.7%, respectively). Patients in the VKA+APL group more frequently discontinued VKA than patients in the VKA alone group (28.8% vs 24.2%, P = 0.045). Major causes of VKA discontinuation were uncontrolled INR level and patient dissatisfaction or concerns. Conclusions The conditions of NVAF patients were inadequately controlled with VKA with or without an APL. These findings suggest that other antithrombotic treatment options are warranted in NVAF patients to achieve INR control.

Background Fasciculoventricular (FV) bypass tracts (BTs) are the rarest form of ventricular preexcitation. Although they are not involved in clinically significant reentrant tachycardia, they may cause diagnostic and therapeutic confusion if not properly understood. This study aimed to assess the impact of FV BTs on the diagnosis and treatment of concomitant arrhythmias and cardiac diseases. Methods Twenty-two patients with FV BTs who underwent electrophysiologic (EP) study were evaluated. The prevalence of concomitant arrhythmias and cardiac diseases in FV BTs was evaluated. The mechanisms of concomitant arrhythmias were determined by EP study and cardiac diseases were diagnosed by echocardiography. Results One patient had FV BT with complete infra-Hisian atrioventricular (AV) block that mimicked a slow ventricular escape rhythm. Two patients had FV BT with atrial fibrillation or atrial flutter, which was misinterpreted as AV BT requiring emergency DC cardioversion. Eight patients had accompanying AV BTs. In 2 patients with AV BTs, unnecessary RF application was delivered after successful ablation of AV BT because conduction through a FV BT was mistaken for conduction through a residual AV BT. Five patients had no concomitant arrhythmia; however, two of them had hypertrophic cardiomyopathy with symptoms requiring beta-blocker. Patients had not been prescribed beta-blockers to avoid a proarrhythmic response before the EP study because the FV BTs mimicked AV BTs. Conclusion FV BTs were frequently accompanied by AV BTs or other arrhythmias and cardiac diseases. They may cause misdiagnosis and inappropriate therapy and even unnecessary RF delivery when misinterpreted as AV BTs.

Background Radiofrequency catheter ablation (RFCA) for accessory pathways (APs) at the site of prior valve surgery (VS) remains challenging. We aimed to clarify the factors associated with successful RFCA for such APs. Methods Upon reviewing a RFCA registry and previous case reports, we included nine patients who underwent RFCA of APs at the site of prior VS (total‐VS group; age, 34.0 [24.5‐45.0] years; men, 4/9) and 196 patients who underwent RFCA of APs with no history of VS (no‐VS group; age, 40.5 [23.0‐54.0] years; men, 114/196). Electrophysiological features, procedural details, and outcomes were examined. Results Accessory pathway exhibited decremental conduction in four of nine patients in the total‐VS group. The number of RFCA attempts was significantly higher in the total‐VS group than in the no‐VS group (10.0 [4.5‐14.5] vs 2.0 [1.0‐3.0]; P

Introduction The incidence and predictors of tricuspid regurgitation (TR) after permanent pacemaker (PM) implantations have not been well evaluated. We attempted to determine TR's natural course and predictors, especially focusing on the influence of atrial fibrillation (AF). Methods Data from 530 patients with dual-chamber PMs were evaluated. The main study outcomes were moderate to severe TR and isolated TR (moderate to severe TR without other structural heart diseases [SHDs]) in follow-up echocardiography. Results Over a median follow-up period of 7.6 years, moderate to severe TR developed in 14.5% patients. Of those, concomitant SHD was observed in 51.9% of patients, and 48.1% presented with isolated TR. A multivariable analysis identified the independent predictors of moderate to severe TR (diabetes mellitus [DM], chronic lung disease, preexisting mild TR, peripheral artery disease, moderate to severe aortic regurgitation, and persistent AF [PeAF]) and isolated TR (DM, preexisting mild TR, and PeAF). PeAF (n = 67, 12.6%) was an independent predictor of both moderate to severe TR (hazard ratio [HR] 2.59, 95% confidence interval [CI]: 1.22-5.51) and isolated TR (HR 4.54, 95% CI: 1.60-12.90). The patients with PeAF exhibited a higher incidence of moderate to severe TR (21.8% vs 12.9% vs 11.6% PeAF, paroxysmal AF, and without AF, respectively) and isolated TR (18.6% vs 6.6% vs 4.2%, respectively) during the follow-up. Conclusion Moderate to severe TR after PM implantations developed with or without the influence of concomitant SHD. Patients with PeAF exhibited a higher risk of moderate to severe TR after PM implantations.

Contact force (CF)-sensing technology has enabled accurate real-time CF measurement in tissue. Average CF, which is quantified by the force–time integral (FTI), correlates with lesion volume.Little is known about which of the time and force factors that compose FTI plays a more important role and which is a better index for predicting lesion size, FTI, or force–power–time index (FPTI). Investigators sought to identify a better index for predicting radiofrequency ablation lesion formation with experimental model.Radiofrequency current was delivered to the swine skeletal muscle at radiofrequency energy current was delivered at 4 fixed power settings (15, 25, 30, and 40 W) for 6 variable time durations (5, 10, 20, 30, 40, and 50 s) with 6 variable CF settings (5, 10, 20, 30, 40, and 50 g). At each setting, the following parameters were evaluated: (1) transmural lesion depth, (2) lesion width, and (3) lesion volume. Between FTI factors, the time factor was more important than the force factor for lesion formation. The area under the curve was greater for FPTI (0.943) than for FTI (0.870). On univariate linear regression analysis, the explanatory power of the linear regression model was better explained by FPTI (56.4%) than FTI (32.1%).Under the same FTI condition, the time factor had a greater effect on lesion formation. When power was included, the power factor had a greater effect on lesion formation and steam pop.

Background Severe conduction delay and inter/intra‐atrial dissociation may occur in patients who undergo an extensive catheter ablation or a maze procedure for atrial tachyarrhythmia. We report a series of patients with inter/intra‐atrial dissociation that mimicked complete atrioventricular block or ventricular tachycardia. Methods and Results We retrospectively reviewed the medical records of 7 patients who were referred for the evaluation of atrioventricular block (patients 1–6) or ventricular tachycardia (patient 7) that occurred after biatrial maze procedure and valvular surgery. During the electrophysiologic study, slow atrial or junctional escape rhythm dissociated from isolated atrial activity mimicked complete atrioventricular blocks. Intra‐atrial dissociation of the right atrium or left atrium was observed. Atrioventricular nodal conduction from the nondissociated atrium to the ventricle was preserved in all patients, while the conduction from the dissociated atrium was blocked. In patient 7, the pacing of the ventricle by tracking of atrial tachycardia from the nondissociated left atrium/coronary sinus mimicked ventricular tachycardia during pacemaker interrogation. A total of 5 patients received new permanent pacemaker implantations during the index hospitalization for the surgery (n=2) or as a deferred procedure (n=3) according to the treatment for sick sinus syndrome. Conclusions Pseudo‐atrioventricular block or pseudo‐ventricular tachycardia may occur because of inter/intra‐atrial dissociation after a maze procedure. The selection of patients for permanent pacemaker implantation should be determined based on the patient’s symptoms and the status of the escape pacemaker and not on the apparent atrioventricular block. Proper diagnosis is important to avoid unnecessary implantation of a pacemaker or a defibrillator.

The current thromboembolic risk stratification of non-valvular atrial fibrillation (NVAF) does not include parameters from transthoracic echocardiography (TTE). We hypothesized that left atrial enlargement (LAE) on TTE could discriminate who require anticoagulation therapy among NVAF patients with low/borderline clinical embolic risk. This single-center cohort study included 6,602 patients with NVAF (median age, 56 years, 70.0% male) with a low to borderline clinical embolic risk (CHA2DS2-VASc score: 0 to 1 in males, 1 to 2 in females). LAE was classified as mild (≥41 mm in males; ≥39 mm in females) or moderate-severe (≥47 mm in males; ≥43 mm in females). The main study outcome was thromboembolic event (ischemic stroke and systemic embolism). Mild and moderate-severe LAE was diagnosed in 26.1% and 32.9% of the cohort, respectively. The patients with moderate-severe LAE showed a higher prevalence of baseline comorbidities and valvular heart disease and had a higher incidence of thromboembolic events than patients with mild or no LAE at 2 years of follow-up (2.5% vs 1.3% vs 1.1%, respectively, p

Background An automated tagging module (VISITAG™; Biosense Webster, Irvine, CA) allows objective demonstration of energy delivery. However, the effect of VISITAG™ on clinical outcomes remains unclear. This study evaluated (1) clinical outcome after AF ablation using VISITAG™ and (2) the prevalence of gaps in the ablation line. Methods This retrospective analysis included 157 consecutive patients (mean age, 56.7 years; 73.2% men) with paroxysmal atrial fibrillation who underwent successful PVI between 2013 and 2016. Outcomes after the index procedure were compared between those using the VISITAG™ module (VISITAG group, n = 62) and those not using it (control group, n = 95). The primary outcome was recurrence of AF or atrial tachycardia after a blanking period of 3 months. Results The VISITAG group showed significantly shorter overall procedure time (172.2 ± 37.6 min vs. 286.9 ± 66.7 min, P P P P = 0.189). Gaps in the VISITAG line were common in the both carina and left side pulmonary veins. Patients without gaps (≥ 5 mm) by the criteria emphasizing catheter stability (> 15 s, 60% force over time, > 6 g contact force) showed higher recurrence-free survival rate compared with those with gaps (borderline statistical significance, 91.7% vs. 66.0%, P = 0.094). Conclusion Use of the VISITAG™ module significantly reduced procedure, ablation, and fluoroscopic times with a similar AF/AT recurrence rate compared with the conventional ablation. Clinical implications of minimizing gaps along the ablation line should be evaluated further in the future prospective studies.

Background The left lateral ridge (LLR) is an important structure for ablation of atrial fibrillation (AF). This study assessed how the LLR shape is associated with the long-term outcomes of AF ablation and investigated the relationship with radiofrequency (RF) lesion formation. Methods and results Clinical study - we assessed multi-detector computed tomography (MDCT) images in 247 patients who underwent AF ablation. Patients were classified into two groups according to the shape of the LLR: Narrow LLR group (n = 116; 47%) and Wide LLR group (n = 131; 53%). After a follow-up period 475 ± 245 days, the AF-free rate was significantly higher in the wide LLR than Narrow LLR group (83.2% vs. 62.9%, p = 0.0004). A multivariate analysis showed that the shape of the LLR was an independent predictor of AF recurrence after ablation (hazard ratio 2.58; 95% confidential interval = 1.48–4.51, p = 0.001). Experimental study - Two types of the ridge models were made with porcine atrial tissues: “Narrow ridge(4.2 ± 0.9 mm)” and “Wide ridge(9.7 ± 1.8 mm)” RF ablation was performed on each ridge model using a contact force (CF)-sensing catheter. The mean CF and the RF lesion volume of the narrow ridge were significantly less than those of the wide ridge model (5.42 ± 3.13 g vs. 10.37 ± 3.98 g, p = 0.001; 19.8 ± 9.9 mm3 vs. 44.2 ± 13.6 mm3, p Conclusions AF recurrence after ablation was more frequent in patients with a narrow LLR. LLR shape as assessed using MDCT is associated with long-term outcomes after AF ablation. CF and lesion formation data using the porcine atrial tissue model support our clinical results.

Background and objectives Data regarding the safety of atrial fibrillation (AF) ablation using high-power (50 W) radiofrequency (RF) energy in Asian populations are limited. This study was conducted to evaluate the incidence and pattern of esophageal injury after high-power AF ablation in an Asian cohort. Methods We searched the prospective AF ablation registry to identify patients who underwent AF ablation with 50 W RF energy using the smart touch surround flow catheter (Biosense Webster, Diamond Bar, CA, USA). Visitag™ (Biosense Webster) was used for lesion annotation with predefined settings of catheter stability (3 mm for 5 seconds) and minimum contact force (50% of time >5 g). All patients underwent upper gastrointestinal endoscopy at 1 or 3 days after the ablation. Results A total of 159 patients (mean age: 63±9 years, male: 69%, paroxysmal AF: 45.3%, persistent AF: 27.7%, long-standing persistent AF: 27.0%) were analyzed. Initially, 26 patients underwent pulmonary vein isolation with 50 W for 5 seconds at each point. The remaining 133 patients underwent prolonged RF duration (anterior 10 seconds and posterior 6 seconds). The incidence rates of esophageal erythema/erosion and superficial ulceration were 1.3% for each type of the lesion. Food stasis, a suggestive finding of gastroparesis, was observed in 25 (15.7%) patients. There were no cases of cardiac tamponade, stroke, or death. Conclusions In Asian patients, AF ablations using 50 W resulted in very low rates of mild esophageal complications.

Background The clinical implications of pericardial effusion (PE) after catheter ablation for atrial fibrillation (AF) are not well understood. We evaluated the association between newly developed PE after pulmonary vein isolation (PVI) for paroxysmal AF and arrhythmic recurrence. Methods From a prospective AF ablation registry, 184 patients (mean age 59 ± 10 years, 65% male) who underwent first-time PV isolation using a smart touch surround flow catheter (Biosense Webster, Diamond Bar, CA) were analyzed. Postablation transthoracic echocardiography (TTE) was performed within 1-3 days after ablation, and the occurrence of PE was assessed. Results PE developed in 91 patients (49.5%), and most were of minimal severity (minimal, 93.4%; mild, 6.6%). Patients with PE had significantly lower body mass index and underwent cavotricuspid isthmus ablation more frequently. Early arrhythmic recurrence (EAR) (within 3 months) was observed in 28.8% of patients and was not different according to the PE development (PE [+]: 29.7% vs PE [-]: 28.0%; P = .80). During a median follow-up of 696 days, the cumulative rate of the late arrhythmic recurrence (LAR) (after 3 months) was 36.4%, and there was no difference between groups (PE [+]: 36.7% vs PE [-]: 35.1%; P = .988). The only predictor of LAR was EAR, and no echocardiographic parameters showed a significant correlation with LAR. Conclusions Minimal or mild PE after PVI for paroxysmal AF is a frequent echocardiographic finding, and it had no significant association with AF recurrence. Routine TTE after AF ablation has no clinical implication.

Background The incidence of inappropriate shocks remains high at 30% in patients with implantable cardioverter-defibrillators (ICDs). This retrospective study sought to examine the efficacy of strategic programming (ICD programming with a long detection interval and high-rate cutoff) in reducing electrical storm, inappropriate shocks, and unexpected hospital visits in patients with ICDs with/without cardiac resynchronization therapy with defibrillator (CRT-Ds). Methods This was a single tertiary center retrospective study, evaluating the clinical outcomes, especially regarding inappropriate therapies in patients with ICDs or CRT-Ds. Enrolled patients underwent ICD or CRT-D implantations from January 2008 to May 2016. Clinical information was attained by a thorough chart review. Results We analyzed 155 defibrillator patients from January 2008 to May 2016 (124 patients had ICDs and 31 had CRT-Ds). Since we adopted this strategic programming as a default programming from 2015 implanted ICDs and CRT-Ds, we divided the patients into two groups: devices implanted before 2015 (group A, n = 94) versus implanted after 2015 (group B, n = 61). During a median of 1289 days of follow-up, electrical storms occurred in three patients (eight events) in group B versus 11 (28 events) in group A (P = 0.18); appropriate therapies were delivered in 27 patients (56 events) in group A versus 7 (15 events) in group B (P = 0.72); inappropriate therapies were delivered in 15 patients (21 events) in group A versus 1 with 1 episode in group B (P = 0.03); and 5 unexpected hospitalizations occurred in four patients in group B versus 36 in 24 patients in group A (P = 0.02). Conclusion The clinical application of strategic programming reduced inappropriate shocks and unexpected hospitalizations in ICD and CRT-D patients.

Atrial tachycardias (ATs) from noncoronary aortic cusp (NCC) uncovered after radiofrequency ablation for atrial fibrillation (AF) are rarely reported. This study was conducted to investigate the prevalence and clinical characteristics of NCC ATs detected during AF ablation and compare their characteristics with de novo NCC ATs without AF.Consecutive patients who underwent radiofrequency catheter ablation for AF were reviewed from the multicenter AF ablation registry of 11 tertiary hospitals. The clinical and electrophysiological characteristics of NCC AT newly detected during AF ablation were compared with its comparators (de novo NCC AT ablation cases without AF).Among 10,178 AF cases, including 1,301 redo ablation cases, 8 (0.08%) NCC AT cases were discovered after pulmonary vein isolation (PVI; 0.07% in first ablation and 0.15% in redo ablation cases). All ATs were reproducibly inducible spontaneously or with programmed atrial stimulation without isoproterenol infusion. The P-wave morphological features of tachycardia were variable depending on the case, and most cases exhibited 1:1 atrioventricular conduction. AF recurrence rate after PVI and NCC AT successful ablation was 12.5% (1 of 8). Tachycardia cycle length was shorter than that of 17 de novo ATs from NCC (303 versus 378, p=0.012). No AV block occurred during and after successful AT ablation.Uncommon NCC ATs (0.08% in AF ablation cases) uncovered after PVI, showing different characteristics compared to de-novo NCC ATs, should be suspected irrespective of P-wave morphologies when AT shows broad propagation from the anterior interatrial septum.

BACKGROUND Although the prevalence of both atrial fibrillation (AF) and metabolic syndrome (MetS) has been increasing in East Asia, the association between them is uncertain.Methods and Results:A total of 24,741 middle-aged Korean men without baseline AF were enrolled in a health screening program from January 2003 to December 2008. Among them, 21,981 subjects were evaluated to determine the risk of AF based on baseline MetS status through December 2016. At every visit, the subjects were evaluated for AF using ECG. MetS was defined using the criteria of the International Diabetes Federation and was present in 2,529 subjects (11.5%). Mean (±standard deviation) age was 45.9±5.3 years. During a mean follow-up of 8.7 years, 168 subjects (0.8%) were diagnosed with AF. The age-adjusted and multivariate-adjusted hazard ratios (HR) for MetS with AF were 1.62 (P=0.02) and 1.57 (P=0.03), respectively. Among the components of MetS, central obesity (age-adjusted HR 1.62, P

Rhythm control therapy is the main strategy for restoring and maintaining sinus rhythm in patients with non-valvular atrial fibrillation (NVAF). Sinus rhythm is better restored and maintained with antiarrhythmic drugs than with placebo treatment. In addition, catheter ablation or combination therapy is more effective than antiarrhythmic drugs for treating NVAF. However, in most clinical trials to date, rhythm control therapy has resulted in neutral clinical outcomes compared with rate control therapy. The decision to undergo rhythm control therapy should be based on age, atrial fibrillation (AF)-related symptoms, type of AF, structural heart disease, and underlying comorbidities. For now, rhythm control therapy is indicated to improve symptoms in patients with NVAF who have refractory symptoms after adequate rate control therapy. The Korean Heart Rhythm Society organized the Korean AF Management Guideline Committee and analyzed all available data, including South Korean patients with NVAF. This review article provides general principles and detailed methodology for rhythm control therapy in South Korean patients with NVAF. (Korean J Med 2018;93:140-152)

Atrial fibrillation (AF) is characterized by irregular and relatively rapid heart rate, which occasionally causes symptoms such as palpitations, dyspnea, or reduced exercise capacity. Controlling the ventricular rate is a mainstay for the symptom management of patients with AF. Rate control can be achieved with beta-blockers, non-dihydropyridine calcium channel blockers, digoxin, or combination therapy. Rhythm control is an option for patients in whom appropriate rate control cannot be achieved or who have persistent symptoms despite rate control. The choices of drug and target heart rate are usually specified by international guidelines for AF management. However, pivotal trials included in those guidelines enrolled only a small number of Asian subjects, which limit application of those guidelines to a Korean population. The Korean Heart Rhythm Society organized the Korean AF Management Guideline Committee and analyzed all available studies regarding management of AF including studies with Korean patients. Then, expert consensus or guidelines for optimal management in Korean patients with AF were achieved after systematic review with intensive discussion. This article provides general principles for rate control therapy in Korean patients with AF. (Korean J Med 2018;93:133-139)

Oral anticoagulants (OAC) are necessary to prevent thromboembolism in patients with atrial fibrillation (AF). OACs used in Korea are composed of warfarin and non-vitamin K antagonist OAC. Risk stratification and selection of OACs in patients with AF is usually performed by international guidelines for AF management. However, these guidelines do not always reflect the unique characteristics of AF patients in Korea as they were established based on a small portion of the Asian population and, therefore, have limited application to Korean patients. In addition, under certain conditions, the choice of OACs and doses according to the international guidelines are unsuitable for Korean AF patients. Recently, robust clinical data of Korean AF patients have become available. The Korean AF Management Guideline Committee, as part of the Korean Heart Rhythm Society, analyzed all available studies regarding management of AF including those focusing on Korean patients. Expert consensus and guidelines for optimal management of AF patients in Korea were established following systematic reviews and intensive discussions. This article provides the appropriate choice of OACs and dose for management of Korean AF patients with various clinical conditions. (Korean J Med 2018;93:110-132)

Introduction The ligament of Marshall may hinder the creation of mitral isthmus (MI) block or pulmonary vein (PV) isolation (PVI) in radiofrequency (RF) catheter ablation of atrial fibrillation (AF). We aimed to assess the benefit of RF ablation targeting the vein of Marshall (VOM) in failed cases of MI block or PVI. Methods and Results: We reviewed the medical records of patients who underwent RF ablation targeting the VOM after failed MI ablation or left PVI using the conventional method, which included circumferential point-by-point ablation around the PV antrum and carina, or endocardial MI and epicardial distal coronary sinus (CS) ablation for MI block. The VOM was identified by using selective VOM venography with an external irrigation RF ablation catheter. RF ablation targeting the VOM was performed with RF application at the ostium of the VOM inside the CS or at the endocardial region facing the VOM course. During the set period, CS venography was performed in 42 patients after failure of left PVI (n = 5) or MI block (n = 37). Under CS venography, the VOM was visualised in 22 of 42 patients (MI = 19, PVI = 3). During selective venography of the VOM, no procedure-related complication was observed. RF application targeting the VOM successfully achieved MI block in 13 patients (68.4%) and PVI in 2 (66.7%). Conclusion Selective VOM venography using an irrigated ablation catheter is feasible and safe. RF ablation targeting the VOM may provide additional benefit in failed cases of MI block or PVI. This article is protected by copyright. All rights reserved