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.

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.

Spontaneous type 1 pattern, ventricular arrhythmias and sudden cardiac death in Brugada Syndrome： an updated systematic review and meta-analysis

Brugada syndrome （BrS） is primary electrical disorder characterized by ST segment elevation with right bundle branch block morphology in patients with apparent structurally normal hearts, It predisposes affected individuals to ventricular tachycardia/fibrillation （VT/VF） and sudden cardiac death （SCD）.A number of studies have identified risk factors that are associated with a more malignant course of disease. These include male gender, syncope, a spontaneous type 1 ECG pattern, family history of SCD, family history of Brugada syndrome,

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.

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.

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.

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.

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.

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.

Is cardiac MRI an effective test for arrhythmogenic right ventricular cardiomyopathy diagnosis?

AIM:To evaluate the referrals with suspected arrhythmogenic right ventricular cardiomyopathy(ARVC)and compare cardiac MR(cMR)findings against clinical diagnosis.METHODS:A retrospective analysis of 114(age range16 to 83,males 55%and females 45%)patients referred for cMR with a suspected diagnosis of ARVC between May 2006 and February 2010 was performed after obtaining institutional approval for service evaluation.Reasons for referral including clinical symptoms and family history of sudden death,electrocardiogram and echo abnormalities,cMR findings,final clinical diagnosis and information about clinical management were obtained.The results of cMR were classified as major,minor,non-specific or negative depending on both functional and tissue characterisation and the cMR results were compared against the final clinical diagnosis.RESULTS:The most common reasons for referral included arrhythmias(30%)and a family history of sudden death(20%).Of the total cohort of 114 patients:4 patients(4%)had major cMR findings for ARVC,13patients(11%)had minor cMR findings,2 patients had non-specific cMR findings relating to the right ventricle and 95 patients had a negative cMR.Of the 4 patients who had major cMR findings,3(75%)had a positive clinical diagnosis.In contrast,of the 13 patients who had minor cMR findings,only 2(15%)had a positive clinical diagnosis.Out of the 95 negative patients,clinical details were available for 81 patients and none of them had ARVC.Excluding the 14 patients with no clinical data and final diagnosis,the sensitivity of the test was 100%,specificity 87%,positive predictive value29%and the negative predictive value 100%.CONCLUSION:CMR is a useful tool for ARVC evaluation because of the high negative predictive value as the outcome has a significant impact on the clinical decision-making.

Diagnostic Dilemma of Intracardiac Mass: Tumor versus Thrombus-Case Series and Systematic Review

Background: The differential diagnosis for intracavitary cardiac masses is limited, typically including vegetations, tumors, or thrombi. Cardiac thrombi can often mimic cardiac tumors on imaging, creating a diagnostic challenge. Primary cardiac tumors are rare and usually benign, whereas most cardiac tumors result from metastases, commonly originating from malignancies in the breast, lung, or melanoma. Aim: This report highlights the importance of distinguishing various cardiac masses based on clinical presentations, clinical courses, and radiological features. Case Presentation: We describe two cases of cardiac masses with unique and diverse clinical features. Each case posed significant diagnostic challenges due to their distinct presentations and clinical progressions. Conclusion: These cases underscore the importance of considering both benign and metastatic origins in the differential diagnosis of intracavitary cardiac masses. Accurate differentiation between thrombi and tumors is crucial for appropriate management and treatment.

Comparison of plasma microRNA-1 and cardiac troponin T in early diagnosis of patients with acute myocardial infarction

BACKGROUND:Early reperfusion can effectively treat acute myocardial infarction(AMI) and reduce the mortality signif icantly. This study aimed to compare the role of plasma microRNA-1(miR-1) and cardiac troponin T(cTnT) in early diagnosis of AMI patients.METHODS:From May 2011 to May 2012,plasma samples were collected from 56 AMI patients and 28 non-AMI controls. The expression of plasma miR-1 was measured by quantitative reverse transcription-polymerase chain reaction(qRT-PCR),and the level of plasma cTnT was measured using electrochemiluminescence-based methods on an Elecsys 2010 Immunoassay Analyzer. SPSS 16.0 was used for the statistical analysis of the results. Data were expressed as mean±standard deviation unless otherwise described. The differences about clinical characteristics between the AMI patients and controls were tested using Student's t test or Fisher's exact test. The Mann-Whitney U test was conducted to compare the expression of microRNAs between the AMI patients and controls. MicroRNAs expression between different intervals of the AMI patients was compared using Wilcoxon's signed-rank test. The receiver operating characteristic(ROC) curve was established to discriminate the AMI patients from the controls.RESULTS:In the present study,the expression of plasma miR-1 was signifi cantly increased in the AMI patients compared with the healthy controls(P<0.01). The plasma miR-1 in the AMI patients decreased to the normal level at 14 days(P>0.05). The expression of plasma miR-1 was not related to the clinical characteristics of the study population(P>0.05). ROC curve analyses demonstrated that miR-1 was specifi c and sensitive for the early diagnosis of AMI,but not superior to cTnT.CONCLUSION:Plasma miR-1 could be used in the early diagnosis of AMI,but it is similar to cTnT.

Real-Time Automatic ECG Diagnosis Method Dedicated to Pervasive Cardiac Care

Recent developments of the wireless sensor network will revolutionize the way of remote monitoring in dif-ferent domains such as smart home and smart care, particularly remote cardiac care. Thus, it is challenging to propose an energy efficient technique for automatic ECG diagnosis (AED) to be embedded into the wireless sensor. Due to the high resource requirements, classical AED methods are unsuitable for pervasive cardiac care (PCC) applications. This paper proposes an embedded real-time AED algorithm dedicated to PCC sys-tems. This AED algorithm consists of a QRS detector and a rhythm classifier. The QRS detector adopts the linear time-domain statistical and syntactic analysis method and the geometric feature extraction modeling technique. The rhythm classifier employs the self-learning expert system and the confidence interval method. Currently, this AED algorithm has been implemented and evaluated on the PCC system for 30 patients in the Gabriel Monpied hospital (CHRU of Clermont-Ferrand, France) and the MIT-BIH cardiac arrhythmias da-tabase. The overall results show that this energy efficient algorithm provides the same performance as the classical ones.

Noninvasive Diagnosis of Cardiac Amyloidosis by MRI and Echochardiography

This study described the radiological features on echocardiography and MRI specific to cardiac amyloidosis confirmed on biopsy. Eleven cases of biopsy-proven cardiac amyloidosis were retrospectively reviewed in this study. All patients underwent biopsy, cardiac MRI and echocardiography. The main echocardiography and MRI findings were as follows: diffuse ventricular and septum wall thickening, atrial enlargement, pericardial effusion, restricted left ventricular (LV) systolic and diastolic function, characteristic granular sparkling of myocardium. MRI revealed a characteristic pattern of global subendocardial late enhancement, extending in varying degrees into the neighboring myocardium. The findings agreed with the infiltration distribution of amyloid protein. Typical abnormalities seen on echocardiography and MRI should have important diagnostic and prognostic value of cardiac amyloidosis. MRI should be considered in the diagnosis of cardiac amyloidosis if echocardiographic features are suspicious.

A New Method for Cardiac Diseases Diagnosis

The objective of this work is to perform automatic diagnosis using a non invasive method which consists on the bioimpedance signal processing. Bioimpedance signal (BIS) represents the aorta impedance variation during the heart cycle activity. BIS is detected by mean of two electrodes located at the level of the ascendant aorta. Automatic diagnosis method consists on preparing, first, a data base with a set of cepstral parameters of different BIS according to normal case and different cardiac diseases. This data base is composed from n classes Yk corresponding to n diseases. The classification of anonymous individuals is based on the determination of Fisher distance between anonymous disease and class Yk using Fischer formula. Our method permits to calculate seven relevant cepstral parameters. The application of Fisher method has allowed us to perform the diagnosis of five anonymous cases. The major interest of this method is its especially useful for the exploration of cardiovascular system anomalies for emergency cases, children, elderly and pregnant women who can’t support surgical operations especially at the level of the heart.