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  1. Abdul-Kadir NA, Mat Safri N, Othman MA
    Comput Methods Programs Biomed, 2016 Nov;136:143-50.
    PMID: 27686711 DOI: 10.1016/j.cmpb.2016.08.021
    BACKGROUND: Atrial fibrillation (AF) can cause the formation of blood clots in the heart. The clots may move to the brain and cause a stroke. Therefore, this study analyzed the ECG features of AF and normal sinus rhythm signals for AF recognition which were extracted by using a second-order dynamic system (SODS) concept.
    OBJECTIVE: To find the appropriate windowing length for feature extraction based on SODS and to determine a machine learning method that could provide higher accuracy in recognizing AF.
    METHOD: ECG features were extracted based on a dynamic system (DS) that uses a second-order differential equation to describe the short-term behavior of ECG signals according to the natural frequency (ω), damping coefficient, (ξ), and forcing input (u). The extracted features were windowed into 2, 3, 4, 6, 8, and 10 second episodes to find the appropriate windowing size for AF signal processing. ANOVA and t-tests were used to determine the significant features. In addition, pattern recognition machine learning methods (an artificial neural network (ANN) and a support vector machine (SVM)) with k-fold cross validation (k-CV) were used to develop the ECG recognition system.
    RESULTS: Significant differences (p 
    Matched MeSH terms: Atrial Fibrillation/diagnosis*
  2. Singham KT, Ariffin M
    Med J Malaysia, 1979 Dec;34(2):136-9.
    PMID: 548714
    Matched MeSH terms: Atrial Fibrillation/diagnosis*
  3. Krysiuk OB, Obrezan AG, Zadvorev SF, Yakovlev AA
    Adv Gerontol, 2020;33(1):131-136.
    PMID: 32362096
    In order to analyze the relationship between the athletic qualification and syndrome of cardiac rhythm and conductivity disturbances in former athletes, a retrospective analysis of medical records of 39 male former athletes with cardiovascular complaints (mean age 61,6±11,3 years, mean duration of career in sports 23,9±17,3 years, mean duration of post-athletic period 20,1±9,9 years) was carried out. The patients were screened for cardiac arrhythmias and underwent echocardiography. The overall prevalence of sustained paroxysms of atrial fibrillation was 42%, increasing with the athletic qualification. Ryan grade 4b-5 premature ventricular contractions were found in 14% of patients. 3 parameters were found to be the independent predictors of arrhythmias in former athletes, i. e. athletic qualification, multifocal atherosclerosis (as an anti-risk factor), and age. The coefficient of determinance for the created prognostic model reached 43%. Further prospective studies are needed to validate an algorithm.
    Matched MeSH terms: Atrial Fibrillation/diagnosis*
  4. Mahmod M, Mohd Darul ND, Mokhtar I, Md Nor N, Md Anshar F, Maskon O
    Int J Infect Dis, 2009 Sep;13(5):e316-8.
    PMID: 19541521 DOI: 10.1016/j.ijid.2009.01.017
    While electrocardiogram (ECG) changes are common during viral dengue infection, atrial fibrillation (AF) is a very rare manifestation. It has previously been highlighted that cardiac complications during dengue infection are invariably transient and will spontaneously resolve following recovery from the illness. We present the case of a young patient with IgM- and IgG-positive dengue hemorrhagic fever complicated by AF. ECG revealed a structurally normal heart. The patient remained in AF despite resolution of the illness. Reversion to normal sinus rhythm was achieved after loading of oral amiodarone.
    Matched MeSH terms: Atrial Fibrillation/diagnosis
  5. Chen CH, Chen MC, Gibbs H, Kwon SU, Lo S, On YK, et al.
    Int J Cardiol, 2015 Jul 15;191:244-53.
    PMID: 25978611 DOI: 10.1016/j.ijcard.2015.03.369
    Atrial fibrillation (AF) is the most common heart arrhythmia. Untreated AF incurs a considerable burden of stroke and associated healthcare costs. Asians have AF risk factors similar to Caucasians and a similarly increased risk of AF-related stroke; however, with a vast and rapidly ageing population, Asia bears a disproportionately large disease burden. Urgent action is warranted to avert this potential health crisis. Antithrombotic therapy with oral anticoagulants is the most effective means of preventing stroke in AF and is a particular priority in Asia given the increasing disease burden. However, AF in Asia remains undertreated. Conventional oral anticoagulation with warfarin is problematic in Asia due to suboptimal control and a propensity among Asians to warfarin-induced intracranial haemorrhage. Partly due to concerns about intracranial haemorrhage, there are considerable gaps between AF treatment guidelines and clinical practice in Asia, in particular overuse of antiplatelet agents and underuse of anticoagulants. Compared with warfarin, new direct thrombin inhibitors and Factor Xa inhibitors are non-inferior in preventing stroke and significantly reduce the risk of life-threatening bleeding, particularly intracranial bleeding. These agents may therefore provide an appropriate alternative to warfarin in Asian patients. There is considerable scope to improve stroke prevention in AF in Asia. Key priorities include: early detection of AF and identification of asymptomatic patients; assessment of stroke and bleeding risk for all AF patients; evidence-based pharmacotherapy with direct-acting oral anticoagulant agents or vitamin K antagonists for AF patients at risk of stroke; controlling hypertension; and awareness-raising, education and outreach among both physicians and patients.
    Matched MeSH terms: Atrial Fibrillation/diagnosis
  6. Abdul-Kadir NA, Mat Safri N, Othman MA
    Int J Cardiol, 2016 Nov 01;222:504-8.
    PMID: 27505342 DOI: 10.1016/j.ijcard.2016.07.196
    BACKGROUND: The feasibility study of the natural frequency (ω) obtained from a second-order dynamic system applied to an ECG signal was discovered recently. The heart rate for different ECG signals generates different ω values. The heart rate variability (HRV) and autonomic nervous system (ANS) have an association to represent cardiovascular variations for each individual. This study further analyzed the ω for different ECG signals with HRV for atrial fibrillation classification.

    METHODS: This study used the MIT-BIH Normal Sinus Rhythm (nsrdb) and MIT-BIH Atrial Fibrillation (afdb) databases for healthy human (NSR) and atrial fibrillation patient (N and AF) ECG signals, respectively. The extraction of features was based on the dynamic system concept to determine the ω of the ECG signals. There were 35,031 samples used for classification.

    RESULTS: There were significant differences between the N & NSR, N & AF, and NSR & AF groups as determined by the statistical t-test (p<0.0001). There was a linear separation at 0.4s(-1) for ω of both databases upon using the thresholding method. The feature ω for afdb and nsrdb falls within the high frequency (HF) and above the HF band, respectively. The feature classification between the nsrdb and afdb ECG signals was 96.53% accurate.

    CONCLUSIONS: This study found that features of the ω of atrial fibrillation patients and healthy humans were associated with the frequency analysis of the ANS during parasympathetic activity. The feature ω is significant for different databases, and the classification between afdb and nsrdb was determined.

    Matched MeSH terms: Atrial Fibrillation/diagnosis
  7. Iqbal U, Wah TY, Habib Ur Rehman M, Mujtaba G, Imran M, Shoaib M
    J Med Syst, 2018 Nov 05;42(12):252.
    PMID: 30397730 DOI: 10.1007/s10916-018-1107-2
    Electrocardiography (ECG) sensors play a vital role in the Internet of Medical Things, and these sensors help in monitoring the electrical activity of the heart. ECG signal analysis can improve human life in many ways, from diagnosing diseases among cardiac patients to managing the lifestyles of diabetic patients. Abnormalities in heart activities lead to different cardiac diseases and arrhythmia. However, some cardiac diseases, such as myocardial infarction (MI) and atrial fibrillation (Af), require special attention due to their direct impact on human life. The classification of flattened T wave cases of MI in ECG signals and how much of these cases are similar to ST-T changes in MI remain an open issue for researchers. This article presents a novel contribution to classify MI and Af. To this end, we propose a new approach called deep deterministic learning (DDL), which works by combining predefined heart activities with fused datasets. In this research, we used two datasets. The first dataset, Massachusetts Institute of Technology-Beth Israel Hospital, is publicly available, and we exclusively obtained the second dataset from the University of Malaya Medical Center, Kuala Lumpur Malaysia. We first initiated predefined activities on each individual dataset to recognize patterns between the ST-T change and flattened T wave cases and then used the data fusion approach to merge both datasets in a manner that delivers the most accurate pattern recognition results. The proposed DDL approach is a systematic stage-wise methodology that relies on accurate detection of R peaks in ECG signals, time domain features of ECG signals, and fine tune-up of artificial neural networks. The empirical evaluation shows high accuracy (i.e., ≤99.97%) in pattern matching ST-T changes and flattened T waves using the proposed DDL approach. The proposed pattern recognition approach is a significant contribution to the diagnosis of special cases of MI.
    Matched MeSH terms: Atrial Fibrillation/diagnosis*
  8. Acharya UR, Faust O, Ciaccio EJ, Koh JEW, Oh SL, Tan RS, et al.
    Comput Methods Programs Biomed, 2019 Jul;175:163-178.
    PMID: 31104705 DOI: 10.1016/j.cmpb.2019.04.018
    BACKGROUND AND OBJECTIVE: Complex fractionated atrial electrograms (CFAE) may contain information concerning the electrophysiological substrate of atrial fibrillation (AF); therefore they are of interest to guide catheter ablation treatment of AF. Electrogram signals are shaped by activation events, which are dynamical in nature. This makes it difficult to establish those signal properties that can provide insight into the ablation site location. Nonlinear measures may improve information. To test this hypothesis, we used nonlinear measures to analyze CFAE.

    METHODS: CFAE from several atrial sites, recorded for a duration of 16 s, were acquired from 10 patients with persistent and 9 patients with paroxysmal AF. These signals were appraised using non-overlapping windows of 1-, 2- and 4-s durations. The resulting data sets were analyzed with Recurrence Plots (RP) and Recurrence Quantification Analysis (RQA). The data was also quantified via entropy measures.

    RESULTS: RQA exhibited unique plots for persistent versus paroxysmal AF. Similar patterns were observed to be repeated throughout the RPs. Trends were consistent for signal segments of 1 and 2 s as well as 4 s in duration. This was suggestive that the underlying signal generation process is also repetitive, and that repetitiveness can be detected even in 1-s sequences. The results also showed that most entropy metrics exhibited higher measurement values (closer to equilibrium) for persistent AF data. It was also found that Determinism (DET), Trapping Time (TT), and Modified Multiscale Entropy (MMSE), extracted from signals that were acquired from locations at the posterior atrial free wall, are highly discriminative of persistent versus paroxysmal AF data.

    CONCLUSIONS: Short data sequences are sufficient to provide information to discern persistent versus paroxysmal AF data with a significant difference, and can be useful to detect repeating patterns of atrial activation.

    Matched MeSH terms: Atrial Fibrillation/diagnosis*
  9. Choi EK, Lee YS, Chern AKC, Jiampo P, Chutinet A, Hanafy DA, et al.
    Open Heart, 2020 11;7(2).
    PMID: 33184127 DOI: 10.1136/openhrt-2020-001343
    BACKGROUND AND PURPOSE: Real-world data about treatment convenience and satisfaction in Asian non-valvular atrial fibrillation (NVAF) patients after switching from vitamin K antagonists (VKAs) to non-VKA oral anticoagulants were evaluated.

    METHODS: In this non-interventional study involving 49 sites across five countries in Southeast Asia and South Korea, 379 stable NVAF patients who switched from VKA therapy to dabigatran during routine clinical practice were recruited and followed up for 6 months. Treatment convenience and satisfaction were evaluated using Perception on Anticoagulant Treatment Questionnaire-2 (PACT-Q2). Through post hoc analysis, factors associated with improved treatment convenience scores at visit 2 were described.

    RESULTS: Treatment convenience and satisfaction significantly improved after switching from VKAs to dabigatran at visit 2 and visit 3 (convenience: p<0.001 each vs baseline; satisfaction: p=0.0174 (visit 2), p=0.0004 (visit 3) compared with baseline). Factors predictive of higher (>80th percentile) response on treatment convenience were female sex, younger age (<75 years), higher baseline stroke risk, higher creatinine clearance and absence of concomitant hypertension, stroke or gastrointestinal diseases.

    CONCLUSION: Dabigatran was associated with a significant improvement in treatment convenience and satisfaction after switching from VKAs when used for stroke prevention in NVAF patients from Southeast Asia and South Korea.

    Matched MeSH terms: Atrial Fibrillation/diagnosis
  10. Beshir SA, Chee KH, Lo YL
    Int J Clin Pharm, 2016 Oct;38(5):1182-90.
    PMID: 27450507 DOI: 10.1007/s11096-016-0350-1
    Background Oral anticoagulant therapy is indicated for the prevention of stroke or other thromboembolic events. Premature discontinuation of oral anticoagulants may increase the risk of thromboembolism resulting in adverse sequelae. There are sparse data on the prevalence and the predictors of dabigatran discontinuation in Malaysian patients with atrial fibrillation. Objectives Determine the reasons and identify associated factors for abrupt discontinuation of dabigatran, assess the switching pattern and the occurrence of thromboembolic events after dabigatran discontinuation. Setting A university-affiliated tertiary hospital in Kuala Lumpur, Malaysia. Methods The clinical and demographic data of a cohort who were initiated with dabigatran between 2010 and 2012 at the University of Malaya Medical Centre were reviewed until the date of death or on 31st December 2013. Those patients who discontinued dabigatran were further followed up until 31st December 2015 to determine the occurrence of any thromboembolic event. Main outcome measure Permanent discontinuation of dabigatran for more than 8 weeks. Results 26 (14 %) of a cohort of 192 patients discontinued dabigatran therapy during a median follow-up period of 20 (range 3-45) months. About one-half of the discontinuation occurred within the first 6 months of dabigatran use. The three most cited reasons for discontinuation are bleeding events (19 %), high out-of-pocket drug payment (19 %) and cardioversion (19 %). Heart failure [adjusted odds ratio 3.699 (95 % confidence interval 1.393-9.574)] or chronic kidney disease [adjusted odds ratio 5.211 (95 % confidence interval 1.068-23.475)] were found to be independent risk factors for abrupt dabigatran discontinuation. Patients who discontinued dabigatran received warfarin (38 %), antiplatelet agents (16 %) or no alternative antithrombotic therapy (46 %). Five of the 26 patients who discontinued dabigatran developed an ischaemic stroke within 3-34 months after discontinuation. Conclusion Abrupt dabigatran discontinuation without an alternative oral anticoagulant increases the risk of thromboembolic events. As adverse drug events and renal impairment contribute substantially to the premature discontinuation of dabigatran, it is important to identify and monitor patients at risk to reduce dabigatran discontinuation rate especially during the first six months of dabigatran therapy.
    Matched MeSH terms: Atrial Fibrillation/diagnosis
  11. Leschke M, Waliszewski M, Pons M, Champin S, Nait Saidi L, Mok Heang T, et al.
    Catheter Cardiovasc Interv, 2016 Sep;88(3):358-66.
    PMID: 26650913 DOI: 10.1002/ccd.26261
    OBJECTIVES: This observational study assessed the 9-month clinical outcomes in an « all comers » population with a focus on patients with atrial fibrillation (AF) after thin strut bare metal stenting.

    BACKGROUND: Drug eluting stent (DES) implantation is the treatment of choice for coronary artery disease (CAD) leaving only marginal indications for the use of bare metal stents (BMS). However, selected treatment populations with DES contraindications such as patients who cannot sustain 6-12 months of dual antiplatelet therapy (DAPT) remain candidates for BMS implantations.

    METHODS: Thin strut bare metal stenting in a priori defined subgroups were investigated in a non-randomized, international, multicenter «all comers» observational study. Primary endpoint was the 9-month TLR rate whereas secondary endpoints included the 9-month MACE and procedural success rates.

    RESULTS: A total of 783 patients of whom 98 patients had AF underwent BMS implantation. Patient age was 70.4 ± 12.8 years. Cardiovascular risk factors in the overall population were male gender (78.2%, 612/783), diabetes (25.2%, 197/783), hypertension (64.1%, 502/783), cardiogenic shock (4.9%, 38/783) and end stage renal disease (4.9%, 38/783). In-hospital MACE was 4.1% (30/783) in the overall population. The 9-month TLR rate was 4.5% (29/645) in the non-AF group and 3.3% (3/90) in the AF group (P = 0.613). At 9 months, the MACE rate in the AF-group and non-AF group was not significantly different either (10.7%, 69/645 vs. 6.7%, 6/90; P = 0.237). Accumulated stroke rates were 0.3% (2/645) in the non-AF subgroup at baseline and 1.1% (1/90) in the AF subgroup (P = 0.264).

    CONCLUSION: Bare metal stenting in AF patients delivered acceptably low TLR and MACE rates while having the benefit of a significantly shorter DAPT duration in a DES dominated clinical practice. © 2015 Wiley Periodicals, Inc.

    Matched MeSH terms: Atrial Fibrillation/diagnosis
  12. Joseph PG, Healey JS, Raina P, Connolly SJ, Ibrahim Q, Gupta R, et al.
    Cardiovasc Res, 2021 05 25;117(6):1523-1531.
    PMID: 32777820 DOI: 10.1093/cvr/cvaa241
    AIMS: To compare the prevalence of electrocardiogram (ECG)-documented atrial fibrillation (or flutter) (AF) across eight regions of the world, and to examine antithrombotic use and clinical outcomes.

    METHODS AND RESULTS: Baseline ECGs were collected in 153 152 middle-aged participants (ages 35-70 years) to document AF in two community-based studies, spanning 20 countries. Medication use and clinical outcome data (mean follow-up of 7.4 years) were available in one cohort. Cross-sectional analyses were performed to document the prevalence of AF and medication use, and associations between AF and clinical events were examined prospectively. Mean age of participants was 52.1 years, and 57.7% were female. Age and sex-standardized prevalence of AF varied 12-fold between regions; with the highest in North America, Europe, China, and Southeast Asia (270-360 cases per 100 000 persons); and lowest in the Middle East, Africa, and South Asia (30-60 cases per 100 000 persons) (P 

    Matched MeSH terms: Atrial Fibrillation/diagnosis
  13. Freestone B, Rajaratnam R, Hussain N, Lip GY
    Int J Cardiol, 2003 Oct;91(2-3):233-8.
    PMID: 14559136
    BACKGROUND: There are established differences in cardiovascular disease in different racial groups. Worldwide, the literature regarding the clinical epidemiology of atrial fibrillation in non-white populations is scarce.

    OBJECTIVES: To document the prevalence of atrial fibrillation (AF) in the multiracial population of Malaysia, and to describe the clinical features and management of these patients.

    SETTING: Busy city centre general hospital in Kuala Lumpur, Malaysia, over a 1-month period.

    SUBJECTS: One-thousand four hundred and thirty-five acute medical admissions, of whom 40 patients (2.8%) had AF.

    RESULTS: Of 1435 acute medical admissions to Kuala Lumpur General Hospital over the 4-week study period, 40 had AF (21 male, 19 female; mean age 65 years). Of these, 18 were Malay, 16 Chinese and six Indian. Nineteen patients had previously known AF (seven with paroxysmal AF) and 21 were newly diagnosed cases. The principal associated medical conditions were ischaemic heart disease (42.5%), hypertension (40%) and heart failure (40%). Dyspnoea was the commonest presentation, whilst stroke was the cause of presentation in only two patients. Investigations were under-utilised, with chest X-ray and echocardiography in only 62.5% of patients and thyroid function checked in 15%. Only 16% of those with previously diagnosed AF were on warfarin, with a further three on aspirin. Anticoagulant therapy was started in 13.5% of patients previously not on warfarin, and aspirin in 8%. Records of contraindications to warfarin were unreliable, being identified in only 25%. For those with known AF, 58% were on digoxin. For new onset AF, digoxin was again the most common rate-limiting treatment, initiated in 38%, whilst five patients with new onset AF were commenced on amiodarone. DC cardioversion was not used in any of the patients with new onset AF.

    CONCLUSION: Amongst acute medical admissions to a single centre in Malaysia the prevalence of AF was 2.8%. Consistent with previous similar surveys in mainly western (caucasian) populations, standard investigations in this Malaysian cohort were also inadequate and there was underuse of anticoagulation, medication for ventricular rate control and cardioversion to sinus rhythm.

    Matched MeSH terms: Atrial Fibrillation/diagnosis
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