Cardiac arrhythmias detection in an ECG beat signal using fast fourier transform and artificial neural network

Cardiac Arrhythmias shows a condition of abnor-mal electrical activity in the heart which is a threat to humans. This paper presents a method to analyze electrocardiogram (ECG) signal, extract the fea-tures, for the classification of heart beats according to different arrhythmias. Data were obtained from 40 records of the MIT-BIH arrhythmia database (only one lead). Cardiac arrhythmias which are found are Tachycardia, Bradycardia, Supraventricular Tachycardia, Incomplete Bundle Branch Block, Bundle Branch Block, Ventricular Tachycardia. A learning dataset for the neural network was obtained from a twenty records set which were manually classified using MIT-BIH Arrhythmia Database Directory and docu- mentation, taking advantage of the professional experience of a cardiologist. Fast Fourier transforms are used to identify the peaks in the ECG signal and then Neural Networks are applied to identify the diseases. Levenberg Marquardt Back-Propagation algorithm is used to train the network. The results obtained have better efficiency then the previously proposed methods.

Amiodarone Therapy for Cardiac Arrhythmias: Is It Associated with the Development of Cancers?

Amiodarone is used worldwide to treat cardiac arrhythmias, as well as highly symptomatic cases of atrial fibrillation. With this expanded use, especially following its 1985 United States Food and Drug Administration approval, and its use as a long-term therapy in common practice, reports of cancers temporarily related to amiodarone have begun to increase. Animal studies, several clinical trials, numerous case reports, and a population-based cohort study have suggested that cancers may be associated with amiodarone use. This review focuses on the ever increasing evidence in the literature that suggests amiodarone therapy, especially with long-term use, may increase the potential risk of cancer development. It also expresses the need for more definitive studies to be conducted to provide clinicians with a clear answer to this important question.

Short-term exposure to ambient ozone associated with cardiac arrhythmias in healthy adults

Objective The exact biological mechanism whereby exposure to ambient ozone(O3)may contribute to clinical onset of cardiovascular events remains unclear.In this study,we aim to examine the impacts of O3 exposure on cardiac arrhythmias and potential pathways involved through autonomic dysfunction and myocardial injury.Methods Seventy-three non-smoking healthy adults were followed with 4 repeated measurements of 24-hour ambulatory arrhythmias,heart rate variability,ST-segment deviation,and blood pressure(BP)in Beijing,China,2014‒2016.Generalized additive mixed models coupled with distributed lag nonlinear models were constructed to evaluate the associations and potential interlinks between O3 exposure and outcome measurements.Results During the study period,24-hour average concentrations of ambient O3 were 47.4µg/m3(ranging from 1.0 to 165.9µg/m3).Increased risks of premature ventricular contraction and ventricular tachycardia were associated with interquartile range increases in O3 exposure during the last 5 days before each participant's clinic visit,with relative risks of 2.14(95%confidence interval[CI]:1.95 to 2.32)and 5.47(95%CI:3.51 to 7.43),respectively.Mediation analyses further showed that sympathetic activation,parasympathetic inhibition,and elevated BP levels,as well as heightened risks of ST-segment depression could mediate up to 47.74%of the risks of arrhythmias attributable to O3 exposure.Conclusion Our results suggest that short-term exposure to ambient O3 could prompt the genesis of arrhythmias partially through worsening autonomic function and myocardial burden.

Control of cardiac excitability and arrhythmias by microRNAs

Recent studies revealing the important roles of microRNAs（miRNAs） in regulating expression of ion channel genes have opened up a research field for extending and deepening our investi- gation into the cardiac excitability and the associated arrhythmogenesis.Cardiac excitability,the fundamental property of the cardiac myocytes,defines the cardiac conduction,repolarization,automaticity,intracellular calcium handling,and their regional heterogeneity. Our previous and ongoing studies and the work from other laboratories have demonstrated the significant involvement of miRNAs in regulating every aspects of cardiac excitability.We have found earlier that the muscle-specific miRNA miR-1 boosts up the arrhythmogenic potential through targeting gap junction channel connexin 43 in myocardial infarction.A subsequent study revealed that miR-1 can also cause arrhythmias by impairing Ca2+ handling by targeting phosphatase.We then identified another muscle-specific miRNA miR-133 promotes abnormal QT prolongation by repressing HERG K+ channel expression in diabetic cardiomyopathy. Subsequently,we discovered that both miR- 1 and miR-133 are involved in the reexpression of pacemaker channels HCN2/HCN4 to enhance abnormal automaticity in cardiac hypertrophy.Recently, we further identified miR-328 as an important determinant for atrial fibrillation（AF） and the associated adverse atrial electrical remodeling via targeting L-type Ca2+ channels.While all the above-mentioned miRNAs are proarrhythmic,we have newly identified for the first time a natural antiarrhythmic miRNA miR-26.We found that all three members of the miR-26 family is downregulated in their expression in AF tissues and this downregulation increases AF vulnerability as a result of removal of an endogenous antiarrhythmic factor.miR-26 downregulation shortens atrial action potential favoring AF by increasing inward rectifier K+ current（IK1） density. This is caused by an upregulation of Kir2.1 K+ channel subunit due to derepression of its encoding gene KCNJ2 as we have validated KCNJ2 as a target gene for miR-26.Administration of a LNA-modified antimiR-26 antisense through tail vein injection increases AF vulnerability as indicated by increased number of mice with AF induction by intracardiac pacing.And this effect is blunted by co-injection of either an adenovirus vector carrying miR-26 precursor sequence or a LNA-modified miR-26 mimic to specifically target KCNJ2.We further discovered that the activity of NFAT transcription factor is enhanced in AF which represses the transcription of miR-26. We characterized the promoter region of the host genes of all three members of the miR-26 miRNA family and identified a common cis-acting element for NFAT binding.Thus,our study unraveled a novel miRNA signaling pathway AF NFAT miR-26 KC-NJ2 /Kir2.1/IK1 AF as a positive feedback loop favoring AF and the remodeling process.

Dysglycemia and arrhythmias

Disorders in glucose metabolism can be divided into three separate but interrelated domains,namely hyperglycemia,hypoglycemia,and glycemic variability.Intensive glycemic control in patients with diabetes might increase the risk of hypoglycemic incidents and glucose fluctuations.These three dysglycemic states occur not only amongst patients with diabetes,but are frequently present in other clinical settings,such as during critically ill.A growing body of evidence has focused on the relationships between these dysglycemic domains with cardiac arrhythmias,including supraventricular arrhythmias(primarily atrial fibrillation),ventricular arrhythmias(malignant ventricular arrhythmias and QT interval prolongation),and bradyarrhythmias(bradycardia and heart block).Different mechanisms by which these dysglycemic states might provoke cardiac arrhythmias have been identified in experimental studies.A customized glycemic control strategy to minimize the risk of hyperglycemia,hypoglycemia and glucose variability is of the utmost importance in order to mitigate the risk of cardiac arrhythmias.

Inherited arrhythmias and gene therapy: Are there any ethical considerations to take into account?

Interventional electrophysiology represents a relatively recent subspecialty within the field of cardiology.In the past half-century,there has been significant advan-cement in the development and implementation of innovative ablation treatments and approaches.However,the treatment of arrhythmias continues to be inade-quate.Several arrhythmias,such as ventricular tachycardia and atrial fibrillation,pose significant challenges in terms of therapeutic efficacy,whether through interventional procedures or the administration of antiarrhythmic drugs.Cardio-logists are engaged in ongoing research to explore innovative methodologies,such as genome editing,with the purpose of effectively managing arrhythmias and meeting the growing needs of patients afflicted with rhythm disturbances.The field of genome editing has significant promise and has the potential to serve as a highly effective personalized therapy for rhythm disorders in patients.However,several ethical issues must be considered.

Cardiac arrhythmias and cardiac arrest related to mushroom poisoning: A case report

BACKGROUND Mushroom exposure is a global health issue.The manifestations of mushroom poisoning (MP) may vary.Some species have been reported as rhabdomyolytic,hallucinogenic,or gastrointestinal poisons.Critical or even fatal MPs are mostly attributable to Amanita phalloides,with the development of severe liver or renal failure.Myocardial injury and even cases mimicking ST-segment elevation myocardial infarction (STEMI) have been previously reported,while cardiac arrhythmia or cardiac arrest is not commonly seen.CASE SUMMARY We report a 68-year-old woman with MP who suffered from delirium,seizure,long QT syndrome on electrocardiogram (ECG),severe cardiac arrhythmias of multiple origins,and cardiac arrest.She was intubated and put on blood perfusion.Her kidney and liver functions were intact;creatine kinase-MB was mildly elevated,and then fell within normal range during her hospital stay.We sent the mushrooms she left for translation elongation factor subunit 1α,ribosomal RNA gene sequence,and internal transcribed spacer sequence analyses.There were four kinds of mushrooms identified,two of which were found to be toxic.CONCLUSION This is the first time that we found cardiac toxicity caused by Panaeolus subbalteatus and Conocybe lactea,which were believed to be toxic to the liver,kidney,and brain.We suggest that intensive monitoring and ECG follow-up are essential to diagnose prolonged QT interval and different forms of tachycardia in MP patients,even without the development of severe liver or renal failure.The mechanisms need to be further investigated and clarified based on animal experiments and molecular signal pathways.

Athletes and Arrhythmias

Sudden cardiac death related to athletic competition is a rare but tragic event.The victims are typically young with no previous cardiovascular symptoms or limitations.The majority of sudden cardiac death events in athletes are due to ventricular arrhythmias as a result of underlying molecular and/or structural level pathologic substrate.In this article,we will review the physiologic cardiac adaptations to exercise along with arrhythmias seen in athletes with a focus on those commonly associated with sudden cardiac death.

Recent impact study of automatic search function of the pacemaker atrial hysteresis on atrial arrhythmias

Objective:To explore the recent influences of pacemaker with automatic search function of atrial hysteresis on atrial arrhythmias,and to evaluate it clinical efficacy and safety.Methods:Indentify ADx DDD 5286 implanted dual chamber pacemaker for sick sinus syndrome in 43 cases.Automatic search of atrial lag was not opened with after pacemaker implantation,and the pacemaker settings were kept.Follow-up program after 3 months,DDD mode with automatic search of atrial lag was opened,and this mode was followed up for 6 months,comparing the atrial pacing percentage and DCG atrial tachyarrhythmias of pacemaker implantation to opening atrium lag mode.Results:Compared with the preoperative and operative 3 months later,dynamic electrocardiogram(DCG)24 h showed that the number of atrial premature beats(APB)and atrial tachycardia,atrial fibrillation(AF)array increased(p<.05);the cases of APB,atrial tachycardia and AF episodes were also increased(p<.05).Compared with the automatic search function in atrial hysteresis model opened with and not opened:atrial pacing percentage decreased[0.54(0.41,0.71)vs.0.82(0.65,0.93),p<.05];DCG 24 h showed that the number of APB,AF episodes was reduced(p<.05).Conclusions:Automation search function in atrial hysteresis model can obviously reduce the proportion of atrial pacing,reduce the occurrence of atrial arrhythmias;opened with automatic search function in atrial hysteresis model was safe and reliable.

Expert Consensus on Wenxin Granule for Treatment of Cardiac Arrhythmias

INTRODUCTIONAntiarrhythmic drugs remain a critically important component of the approach to therapy of cardiac arrhythmias. Over the past 20 years, despite their antiarrhythmic efficacy in many pathological settings, Class Ⅰ and Ⅲ antiarrhythmic drugs have been shown to be associated with the development of proarrhythmias and an increase in the likelihood of causing higher mortality by inducing torsade de pointes ventricular tachycardia and other serious adverse reactions. Consequently, the development of safe and effective antiarrhythmic regimens remains a primary focus of contemporary cardiovascular research.

Nonalcoholic Fatty Liver Disease (NAFLD) and Risk of Cardiac Arrhythmias: A New Aspect of the Liver-heart Axis

Nonalcoholic fatty liver disease (NAFLD) is a pathologic condition frequently observed in clinical practice.To date,the prevalence of NAFLD is approximately 25-30% among adults of the general population in Western countries but increases to approximately 70-75% among patients with type 2 diabetes mellitus.In the last decade,accumulating evidence has clearly demonstrated that patients with NAFLD have not only an increased liver-related morbidity and mortality but also an increased risk of fatal and non-fatal cardiovascular events.In particular,several studies have documented the existence of an independent association among NAFLD and cardiac changes in structure and function in both non-diabetic and diabetic patients.In addition,mounting evidence also suggests that there is a strong relationship between NAFLD and cardiac arrhythmias,such as atrial fibrillation,QTc prolongation and ventricular arrhythmias.This is of clinical interest,as it could explain,at least in part,the increased risk of death for cardiovascular disease in patients with NAFLD.Therefore,seeing that cardiovascular disease complications are the leading cause of disability and death in NAFLD patients,the recent European clinical practice guidelines advised to check the cardiovascular system in all patients with NAFLD.This clinical mini review will briefly describe the increasing body of evidence regarding the association between NAFLD and cardiac arrhythmias,and discuss the potential biological mechanisms underlying this association.

Influence of the Right Ventricular Lead Location on Ventricular Arrhythmias in Cardiac Resynchronization Therapy

Background： The influence of different right ventricular lead locations on ventricular arrhythmias （VTA） in patients with a cardiac resynchronization therapy （CRT） is not clear. This study aimed to evaluate the influence on VTA in patients with a CRT when right ventricular lead was positioned at the right ventricular middle septum （RVMS） and the right ventricular apical （RVA）. Methods： A total of 352 patients implanted with a CRT-defibrillator （CRT-D） between May 2012 and July 2016 in the Department of Cardiology of Anhui Provincial Hospital were included. Two-year clinical and pacemaker follow-up data were collected to evaluate the influence of the right ventricular lead location on VTA. Patients were divided into the RVMS group （n = 155） and the RVA group （n = 197） based on the right ventricular lead position. The VTA were compared between these two groups using a Kaplan-Meier curve and Cox multivariate analysis. Results： When the left ventricular lead location was not considered, RVMS and RVA locations did not affect VTA. However, the subgroup analysis results showed that when the left ventricular lead was positioned at the anterolateral cardiac vein （ALCV）, the RVMS group had an increased risk ofventricular arrhythmias and appropriate defibrillation （hazard ratio [HR] - 3.29, P = 0.01 and HR = 4.33, P 〈 0.01, respectively）; when the left ventricular lead was at the posterolateral cardiac vein （PLCV）, these risks in the RVMS group decreased （HR = 0.45, P = 0.02 and HR = 0.33, P 〈 0.01, respectively）, and when the lett ventricular lead was at the lateral cardiac vein, there was no difference between the two groups. In regard to inappropriate defibrillation, there was no significant difference among all these groups. Conclusions： When the left ventricular lead was positioned at ALCV or PLCV, the right ventricular lead location was associated with VTA and appropriate defibrillation after CRT. Greater distances between leads not only improved cardiac function but also may reduce the risk of VTA.

Automatic Classification of Cardiac Arrhythmias Based on Hybrid Features and Decision Tree Algorithm

Accurate classification of cardiac arrhythmias is a crucial task because of the non-stationary nature of electrocardiogram(ECG)signals.In a life-threatening situation,an automated system is necessary for early detection of beat abnormalities in order to reduce the mortality rate.In this paper,we propose an automatic classification system of ECG beats based on the multi-domain features derived from the ECG signals.The experimental study was evaluated on ECG signals obtained from the MIT-BIH Arrhythmia Database.The feature set comprises eight empirical mode decomposition(EMD)based features,three features from variational mode decomposition(VMD)and four features from RR intervals.In total,15 features are ranked according to a ranker search approach and then used as input to the support vector machine(SVM)and C4.5 decision tree classifiers for classifying six types of arrhythmia beats.The proposed method achieved best result in C4.5 decision tree classifier with an accuracy of 98.89%compared to cubic-SVM classifier which achieved an accuracy of 95.35%only.Besides accuracy measures,all other parameters such as sensitivity(Se),specificity(Sp)and precision rates of 95.68%,99.28%and 95.8%was achieved better in C4.5 classifier.Also the computational time of 0.65 s with an error rate of 0.11 was achieved which is very less compared to SVM.The multi-domain based features with decision tree classifier obtained the best results in classifying cardiac arrhythmias hence the system could be used efficiently in clinical practices.

Cardiac Arrhythmia Disease Classifier Model Based on a Fuzzy Fusion Approach

Cardiac diseases are one of the greatest global health challenges.Due to the high annual mortality rates,cardiac diseases have attracted the attention of numerous researchers in recent years.This article proposes a hybrid fuzzy fusion classification model for cardiac arrhythmia diseases.The fusion model is utilized to optimally select the highest-ranked features generated by a variety of well-known feature-selection algorithms.An ensemble of classifiers is then applied to the fusion’s results.The proposed model classifies the arrhythmia dataset from the University of California,Irvine into normal/abnormal classes as well as 16 classes of arrhythmia.Initially,at the preprocessing steps,for the miss-valued attributes,we used the average value in the linear attributes group by the same class and the most frequent value for nominal attributes.However,in order to ensure the model optimality,we eliminated all attributes which have zero or constant values that might bias the results of utilized classifiers.The preprocessing step led to 161 out of 279 attributes(features).Thereafter,a fuzzy-based feature-selection fusion method is applied to fuse high-ranked features obtained from different heuristic feature-selection algorithms.In short,our study comprises three main blocks:(1)sensing data and preprocessing;(2)feature queuing,selection,and extraction;and(3)the predictive model.Our proposed method improves classification performance in terms of accuracy,F1measure,recall,and precision when compared to state-of-the-art techniques.It achieves 98.5%accuracy for binary class mode and 98.9%accuracy for categorized class mode.

Repeated atrial arrhythmia induced by cochineal red poisoning:A case report

BACKGROUND Cochineal red is an organic compound widely used in food,cosmetics,pharmaceuticals,textiles,and other fields due to its excellent safety profile.Poisoning caused by eating foods containing cochineal red is rare,and repeated atrial arrhythmia due to cochineal red poisoning is even rarer.CASE SUMMARY An 88-year-old Asian female patient was admitted to hospital due to a disturbance of consciousness.Twelve hours prior to presentation,the patient consumed 12 eggs containing cochineal red over a period of 2 h.At presentation,the patient was in a coma and had a score of 6 on the Glasgow Coma Scale(E2+VT+M4).The patient’s skin and mucous membranes were pink.Electrocardiography(ECG)revealed rapid atrial fibrillation without any signs of ischemia.We prescribed cedilan and fluid replacement for arrhythmia correction.Shortly after admission,the atrial fibrillation corrected to a normal sinus rhythm.On the day 2 of admission,the patient had a sudden atrial flutter accompanied by hemodynamic instability and rapidly declining arterial oxygen saturation between 85%and 90%.The sinus rhythm returned to normal after two electrical cardioversions.Six days after admission,the skin color of the patient returned to normal,and the ECG results were normal.The patient was transferred out of the intensive care unit and eventually discharged after 12 d in hospital.At the 2-mo follow-up visit,the patient was in good health with no recurrence of arrhythmia.CONCLUSION Although cochineal red is a safe,natural food additive,excessive consumption or occupational exposure can induce cardiac arrhythmias.

Associations between cardiac arrhythmia,incident disability in activities of daily living and physical performance:the ILSA study

Background Cardiac arrhythmias are common conditions in older people.Unfortunately,there is limited literature on associations between cardiac arrhythmias and physical performance or disability.We therefore aimed to prospectively investigate associations between cardiac arrhythmias and changes in disability and physical performance during 8 years of follow-up,using data from the Italian Longitudinal Study on Aging(ILSA).Methods Cardiac arrhythmias diagnosis was posed through a screening phase,confirmed by a physician.The onset of disability in activities of daily living(ADL)and the changes in several physical performance tests during follow-up were considered as outcomes.Fully-adjusted and propensity-score Cox Proportional Hazard models and mixed models were used for exploring associations between cardiac arrhythmia and the outcomes of interest.Results The prevalence of cardiac arrhythmia at baseline was 23.3%.People reporting cardiac arrhythmia at the baseline were significantly older,more frequently male,smokers and reported a higher presence of all medical conditions investigated(hypertension,heart failure,angina,myocardial infarction,diabetes,stroke),but no difference in dementia,Parkinsonism,cognitive or mood disorder.Cardiac arrhythmia at baseline was significantly associated with the incidence of disability in ADL(HR=1.23;95%:CI:1.01–1.50;P=0.0478 in propensity score analyses;HR=1.28;95%CI:1.01–1.61;P=0.0401 in fully adjusted models).Cardiac arrhythmia at baseline was also associated with a significant worsening in balance test(P=0.0436).Conclusions The presence of cardiac arrhythmia at baseline was associated with a significant higher risk of disability and of worsening in some physical performance tests,particularly those relating to balance.Screening and frequently assessing physical performance in older people affected by cardiac arrhythmia can be important to prevent a loss of physical performance,with further,potential,complications of medical management.

Cardiac autonomic nerve distribution and arrhythmia

OBJECTIVE： To analyze the distribution characteristics of cardiac autonomic nerves and to explore the correlation between cardiac autonomic nerve distribution and arrhythmia. DATA RETRIEVAL： A computer-based retrieval was performed for papers examining the distribution of cardiac autonomic nerves, using “heart, autonomic nerve, sympathetic nerve, vagus nerve, nerve distribution, rhythm and atrial fibrillation” as the key words. SELECTION CRITERIA： A total of 165 studies examining the distribution of cardiac autonomic nerve were screened, and 46 of them were eventually included. MAIN OUTCOME MEASURES： The distribution and characteristics of cardiac autonomic nerves were observed, and immunohistochemical staining was applied to determine the levels of tyrosine hydroxylase and acetylcholine transferase （main markers of cardiac autonomic nerve distribution）. In addition, the correlation between cardiac autonomic nerve distribution and cardiac arrhythmia was investigated. RESULTS： Cardiac autonomic nerves were reported to exhibit a disordered distribution in different sites, mainly at the surface of the cardiac atrium and pulmonary vein, forming a ganglia plexus. The distribution of the pulmonary vein autonomic nerve was prominent at the proximal end rather than the distal end, at the upper left rather than the lower right, at the epicardial membrane rather than the endocardial membrane, at the left atrium rather than the right atrium, and at the posterior wall rather than the anterior wall. The main markers used for cardiac autonomic nerves were tyrosine hydroxylase and acetylcholine transferase. Protein gene product 9.5 was used to label the immunoreactive nerve distribution, and the distribution density of autonomic nerves was determined using a computer-aided morphometric analysis system. CONCLUSION： The uneven distribution of the cardiac autonomic nerves is the leading cause of the occurrence of arrhythmia, and the cardiac autonomic nerves play an important role in the occurrence, maintenance, and symptoms of arrhythmia.

CARDIAC ARRHYTHMIA AFTER LUNG CANCER SURGERY －－ANALYSIS OF 140 PNEUMONECTTOMY CASES

Among 808 surgically resected lung cancer cases at Shanghai Chest Hospital during 1991 to 1992, 140 of them (17.3%) underwent Pneumonectomy. Of the 140 cases:124 male, 16 female; aged 27-74 yrs, 35.7% elder (60 and over), preoperative abnormal EKG was found in 38 cases, operative mortality was 4.3%. The histopathological diagnosis were: squamous 43.6%, adeno. 36.4%, small cell 8.6%, mixed type 11.4%. The pTNM stages: stage I 2.9%, II 17.1%, IIIa 55.0%, IIIb 21.4%, IV 3.6%.Postoperatively, arrhythmia occuried in 76 cases, with an incidence of 54.3%. Of the 76 arrhythmias, atrial fibrillation was seen in 7 patients, atrial premature beats in 2, supraventricular tachycardia in 1, and sinus tachycardia in 66. The incidences of cadiac arrhythmia during the postoperative day (DO), first day (D1), D2, D3,and D4 were 48.7%, 35.5%, 7.9%, 4.0%and 2.6%respectively. Conclusion: the cardiac arrhythmia is the most common complication after pneumonectomy for lung cancer surgery. The major causes were incisional pain, hypovolemia due to blood loss and respirative insufficiency due to anomia. The perioperative prevention and treatment for arrhythmia were also discussed.

Cardiac arrhythmia and heart failure： From bench to bedside

Cardiac arrhythmia is an abnormal rate and/or rhythm of a heart due to its abnormal electrical impulse origination and/or propagation.Various etiologies can cause arrhythnuas.Heart failure(HF)is a clinical syndrome due to an impaired heart that can not pump sufficient blood to meet the systemic metabolic needs.The common causes of HF include myocardial infarction,hypertension,valvular heart disease,and cardiomyopathy.