• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.12
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• pp.2655-2663
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• 2011

Several algorithms have been developed to detect AF which rely either on the form of P waves or the based on the time frequency domain analysis of RR variability. However, locating the P wave fiducial point is very difficult because of the low amplitude of the P wave and the corruption by noise. Also, the time frequency domain analysis of RR variability has disadvantage to get the details of irregular RR interval rhythm. In this study, we describe an atrial fibrillation detection algorithm through non-linear analysis of irregular RR interval rhythm based on the variability, randomness and complexity. We employ a new statistical techniques root mean squares of successive differences(RMSSD), turning points ratio(TPR) and sample entropy(SpEn). The detection algorithm was tested using the optimal threshold on two databases, namely the MIT-BIH Atrial Fibrillation Database and the Arrhythmia Database. We have achieved a high sensitivity(Se:94.5%), specificity(Sp:96.2%) and Se(89.8%), Sp(89.62%) respectively.

• Journal of Yeungnam Medical Science
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• v.34 no.2
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• pp.242-246
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• 2017

Acute limb ischemia (ALI) due to an embolism is associated with high mortality rate and poor prognosis, and early diagnosis with prompt revascularization is required to reduce the risk of limb amputation or even death. The etiologies of ALI are diverse, and it includes an embolism from the heart and thrombotic occlusion of the atherosclerotic native vessels, stents, or grafts. An uncommon cause of ALI is acute arterial thromboembolism, and atrial fibrillation (AF) is the single most important risk factors for systemic thromboembolism. It is important to correctly identify the source of ALI for secondary prevention, as it depends on the underlying cause. Percutaneous transluminal angioplasty (PTA) has been proven to be a safe and effective treatment for focal atherosclerotic and thrombotic occlusive diseases of the aorta and its major extremity branches. Herein, we report on a 77-year-old female patient with acute upper limb ischemia, treated by PTA using a catheter-guided thrombectomy. He was newly diagnosed with paroxysmal AF (PAF) while evaluation the cause of his acute arterial thromboembolism. We recommend that cardiologists always consider PAF as a possible diagnosis even in patients without any history of AF under ALI because it is possible to develop thromboembolism in clinical practice.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.3
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• pp.38-46
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• 2012

Atrial fibrillation is needed to be detected at paroxysmal stage and to be treated. But, paroxysmal atrial fibrillation ECG is hardly obtained with 12-lead electrocardiographs but Holter systems. Presently, the averaged beat subtraction(ABS) method is solely used to estimate atrial fibrillatory waves even with somewhat large residual error. As an alternative, in this study, we suggested an ESAF(event-synchronous adaptive filter) based algorithm, in which the AF ECG was treated as a primary input and event-synchronous impulse train(ESIT) as a reference. And, ESIT was generated so to be synchronized with the ventricular activity by detecting QRS complex. We tested proposed algorithm with simulated AF ECGs and real AF ECGs. As results, even with low computational cost, this ESAF based algorithm showed better performance than the ABS method and comparable performance to algorithm based on PCA(principal component analysis) or SVD(singular value decomposition). We also proposed an expanded version of ESAF for some AF ECGs with multi-morphologic ventricular activities and this also showed reasonable performance. Ultimately, with Holter systems including our proposed algorithm, atrial activity signal can be precisely estimated in real-time so that it will be possible to calculate atrial fibrillatory rate and to evaluate the effect of anti-arrhythmic drugs.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.4
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• pp.256-264
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• 2022

Ischemic stroke is caused by an occlusion by a thrombus or embolus in a cerebral artery, preventing oxygenated blood from reaching the brain and causing the necrosis of nerve cells. This paper summarizes the serum candidate markers associated with cardiovascular disease and atrial fibrillation (AF) disease that enable an early diagnosis of ischemic stroke studied thus far and compares the odds ratio (OR) of each marker. This study examined the effect size of these serum candidate markers using meta-analysis techniques. The academic database search screening for articles containing the keywords "cardiovascular disease," "atrial fibrillation," "ischemic stroke," and "serum marker" was limited to results for patients with ischemic stroke. The most derived markers in this study were N-terminal pro-B-type natriuretic peptide (NT-pro-BNP), D-dimer, C-reactive protein (CRP), and glial fibrillary acidic protein (GFAP), the rest being investigated individually. In conclusion, NT-pro-BNP appears to be very useful for the early diagnosis of ischemic stroke. Primarily, it is a marker of AF, and more AF markers will be uncovered and studied in the future.

• Journal of Chest Surgery
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• v.54 no.6
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• pp.449-453
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• 2021

The 2020 American College of Cardiology focused update on the mitral regurgitation (MR) pathway provides an excellent summary of the decision-making trees in the treatment of severe MR, in which 2 main branches of the flowchart are suggested depending on whether MR is primary or secondary. Surgery is suggested as preferable over transcatheter edge-to-edge repair (TEER) in primary MR that needs intervention. The decision-making for secondary MR generally prioritizes TEER over surgery according to the guidelines, but further stratification is necessary based on the pathophysiologic mechanisms of MR. TEER is probably the more suitable option in secondary MR caused by left ventricular dysfunction or dilatation, given the high perceived surgical risks, despite the lack of sufficient evidence in support of overt clinical benefits from surgical therapy in these patients. In atrial functional MR associated with atrial fibrillation (AF), however, concomitant ablation of AF seems to be a desirable option, as it has been demonstrated to be a key factor leading to improved survival, reduced stroke risk, and more durable mitral and tricuspid function in patients undergoing mitral surgery. Therefore, atrial functional MR requiring intervention may be best treated by surgical therapy that combines mitral repair and AF ablation in the majority of patients. This particular issue, however, needs further research to obtain scientific evidence to guide optimal management strategies.

• Journal of Chest Surgery
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• v.46 no.2
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• pp.117-123
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• 2013

Background: We examined perioperative predictors of sustained sinus rhythm (SR) in patients undergoing the Cox maze operation and concomitant cardiac surgery for structural heart disease. Materials and Methods: From October 1999 to December 2008, 90 patients with atrial fibrillation (AF) underwent the Cox maze operation and other concomitant cardiac surgery. Eighty-nine patients, all except for one postoperative death, were followed-up with serial electrocardiographic studies, 24-hour Holter monitoring tests, and regular echocardiographic studies. Results: Eighty-nine patients undergoing the maze operation were divided into two groups according to the presence of SR. At the time of last follow-up (mean follow-up period, $51.0{\pm}30.8$ months), 79 patients (88.8%) showed SR (SR group) and 10 patients (11.2%) had recurrent AF (AF group). Factors predictive of sustained SR were the immediate postoperative conversion to SR (odds ratio, 97.2; p=0.001) and the presence of SR at the 6th month postoperatively (odds ratio, 155.7; p=0.002). Duration of AF, mitral valve surgery, number of valves undergoing surgery, left atrial dimension, and perioperative left ventricular dimensions and ejection fractions were not predictors of postoperative maintenance of SR. Conclusion: Immediate postoperative SR conversion and the presence of SR at the 6th postoperative month were independent predictors of sustained SR after the maze operation.

• Journal of Chest Surgery
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• v.29 no.6
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• pp.599-605
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• 1996

A total of 249 patients undergoing isolated coronary revascularization were studied for the occurrence of postoperative atrial fibrillation(AF). Possible associations of this arrhythmia with various preoperative, intraoperative and postoperative factors were studied by univariate and multivariate analysis. The overall incidence of postoperative AF was 15%, with the median time occurence of 48 hours(mean time : 59.1 $\pm$ 56.9 hours) after arrival to the intensive care unit. Cardiac index decreased significantly after occurence of AF(p=0.001). There were no in-hospital complications in those patients with AF. Univariate studies indicated preoperative ejection fract on(EF), triglyceride level, postoperative peak CKMB isoenzpme and atrial pacing to be the dominant factor promoting postoperative AF, with an increasing prevalence in lower EF(p=0.025), triglyceride(p=0.006) and peak CKMB isoenzyme(p=0.002), and in patients with atrial pacing(p=0.001). Hospital stay(p=0.001) and late mortality(p=0.003) were significantly increased in patients with postoperative AF Multivariate analysis showed that body weight and postoperative atrial pacing to be the dominant factor promoting postoperative AF, with an increasing prevalence in over- weight patients(p=0.011) and patients with atrial pacing(p=0.001). Both univariate and multivariate analy- sis showed that the age was not a significant factor but tended to promote postoperative AF respectively (p=0.053, 0.064). After 30.1 $\pm$ 11.4 months gfollow-up, those patients with AF had sinus rhythm. We think that we must try to prevent postoperative AF after ccoronary artery bypass grafting because of its deleterio s hemodynamic effect, prolonged hospital stay, and increased late mortality.

• Korean Circulation Journal
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• v.54 no.5
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• pp.256-267
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• 2024

Background and Objectives: Accumulating evidence shows that sodium-glucose cotransporter 2 inhibitors (SGLT2is) reduce adverse cardiovascular outcomes. However, whether SGLT2i, compared with other antidiabetic drugs, reduce the new development of atrial fibrillation (AF) is unclear. In this study, we compared SGLT2i with dipeptidyl peptidase-4 inhibitors (DPP-4is) in terms of reduction in the risk of AF in individuals with type 2 diabetes. Methods: We included 42,786 propensity score-matched pairs of SGLT2i and DPP-4i users without previous AF diagnosis using the Korean National Health Insurance Service database between May 1, 2016, and December 31, 2018. Results: During a median follow-up of 1.3 years, SGLT2i users had a lower incidence of AF than DPP-4i users (1.95 vs. 2.65 per 1,000 person-years; hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.55-0.97; p=0.028]). In individuals without heart failure, SGLT2i users was associated with a decreased risk of AF incidence (HR, 0.70; 95% CI, 0.52-0.94; p=0.019) compared to DPP-4i users. However, individuals with heart failure, SGLT2i users was not significantly associated with a change in risk (HR, 1.04; 95% CI, 0.44-2.44; p=0.936). Conclusions: In this nationwide cohort study of individuals with type 2 diabetes, treatment with SGLT2i was associated with a lower risk of AF compared with treatment with DPP-4i.

• Korean Circulation Journal
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• v.52 no.8
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• pp.593-603
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• 2022

Background and Objectives: In patients with atrial fibrillation (AF), females taking vitamin K antagonist are at higher risk of stroke or systemic embolism (SSE), bleeding and all-cause death than males. This study investigated the relationship between sex and adverse clinical events in a contemporary AF patient cohort taking anticoagulation. Methods: This prospective multicenter AF registry study comprised 6,067 patients with AF (mean age, 70±9 years; men, 59%) with intermediate to high risk of stroke (CHA₂DS₂-VAscore ≥1) and receiving oral anticoagulation therapy. Adverse clinical outcomes, including SSE, bleeding, death were evaluated in patients stratified by sex and anticoagulation patterns. Results: Women were older and used more direct oral anticoagulants (85% vs. 78%, p<0.001) than men. During a median (25^th and 75^th percentiles) follow-up of 30 (24, 38) months, the incidence rate and risk of SSE (0.7 in women vs. 0.7 in men per 100 person-years) and major bleeding (0.1 in women vs. 0.1 in men per 100 person-years) were not different between the sexes. However, women had a lower all-cause death rate (0.4 in women vs. 0.6 in men per 100 person-years, hazard ratio: 0.48, 95% confidence interval: 0.25-0.91, p=0.025) than men. Conclusions: In contemporary anticoagulation for AF, SSE and major bleeding risks did not differ between sexes. However, women showed a lower risk of all-cause death rate than men, indicating that the use of oral anticoagulants for treating AF in females does not appear to be a risk factor for adverse clinical events.

• International Journal of Heart Failure
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• v.6 no.3
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• pp.119-126
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• 2024

Background and Objectives: Beta-blockers (BBs) improve prognosis in heart failure (HF), which is mediated by lowering heart rate (HR). However, HR has no prognostic implication in atrial fibrillation (AF) and also BBs have not been shown to improve prognosis in heart failure with preserved ejection fraction (HFpEF) with AF. This study assessed the prognostic implication of BB in HFpEF with AF according to discharge HR. Methods: From the Korean Acute Heart Failure Registry, 687 patients with HFpEF and AF were selected. Study subjects were divided into 4 groups based on 75 beats per minute (bpm) of HR at discharge and whether or not they were treated with BB at discharge. Results: Of the 687 patients with HFpEF and AF, 128 (36.1%) were in low HR group and 121 (36.4%) were in high HR group among those treated with BB at discharge. In high HR group, HR at discharge was significantly faster in BB non-users (85.5±9.1 bpm vs. 89.2±12.5 bpm, p=0.005). In the Cox model, BB did not improve 60-day rehospitalization (hazard ratio, 0.93;95% confidence interval [95% CI], 0.35-2.47) or mortality (hazard ratio, 0.77; 95% CI, 0.22-2.74) in low HR group. However, in high HR group, BB treatment at discharge was associated with 82% reduced 60-day HF rehospitalization (hazard ratio, 0.18; 95% CI, 0.04-0.81), but not with mortality (hazard ratio, 0.77; 95% CI, 0.20-2.98). Conclusions: In HFpEF with AF, in patients with HR over 75 bpm at discharge, BB treatment at discharge was associated with a reduced 60-day rehospitalization rate.