Classification of human electrocardiograms by multi-layer convolutional neural network and hyperparameter optimization

Managing atrial fibrillation in the CRT patient: Controversy or consensus?

This research study is to detect the Epileptic seizures using Novel Multi-Layered Convolutional Neural Networks (NMLCNN) and to compare the performance with Fully Convolutional Neural Networks (FCNN). By using Novel Multi-Layered Convolution Neural Networks algorithm works with the data collected from the observations of nervous system cells. The changes in the Epileptic seizures from the resource’s constraint, when the criteria met with randomizing, this will arrange in random ways for n times. The most typical beginning of a seizure is detectable through analysis of the Electroencephalogram (EEG). To examine this, the study utilized 20 samples in each group, with a Gpower value of 80%. The study used a predefined significance value and a Confidence Interval (CI) of 95%.This experiment found that NMLCNN has 92.25% and FCNN has 87.55% of accuracy for epileptic seizure. The Novel Multi-Layered Convolutional Neural Network achieved 0.012 significance using group analysis and provided significance. This probing concludes based on accuracy and significance results, detection of Epileptic seizures using Novel Multi-layered Convolutional Neural Networks has performed better compared to Fully Convolutional Neural Network.

As an electrophysiologist, I am referred large numbers of patients with, or at risk of, arrhythmias as part of the heart failure complex. In this review I will concentrate on the role of pacemakers and defibrillators in heart failure, because these are my areas of greatest experience. Left ventricular assist devices and implantable hemodynamic monitors will not be reviewed. The first controversy for discussion is how to assess patients for suitability to receive these devices. Patients with heart failure are frequently fitted into a New York Heart Association (NYHA) class. The NYHA class is, however, a blunt instrument for decision-making that is based on a physician's or nurse's impression of how patients express their symptoms. Two patients with similar levels of symptomatology but with different responses to their symptoms may therefore receive different NYHA classifications and be candidates for different management approaches. Guidelines such as those from the European Society of Cardiology (ESC) offer valuable guidance on the use of cardiac resynchronization therapy (CRT).12 There are, however, issues in the use of CRT which the guidelines do not consider. Controversies that relate particularly to CRT include the identification of which patients benefit most from this technique and the characterization of its role in atrial fibrillation, in patients with bradycardia, and in non-responders. CRT has been available for approximately 10 years. An early meta-analysis of randomized controlled trials of CRT, including CONTAK-CD, InSync ICD, MIRACLE, and MUSTIC, showed that CRT reduced death from progressive heart failure by 51%, reduced heart failure hospitalization by 29%, and showed a trend to reduced all-cause mortality2 (Figures 12–3). Some of these trials included a defibrillator component, which made characterization of the effects of CRT alone problematic. Subsequent to these trials, the CARE-HF study was performed. CARE-HF observed that CRT produced a 37% reduction in all-cause mortality or unplanned hospitalization compared to medical therapy over 4 years (P < 0.0001)5 (Figure 4). All-cause mortality alone was reduced 36% by CRT when compared to optimal medical therapy (P = 0.0019). CARE-HT was the first major trial to demonstrate a definite improvement in all-cause mortality from CRT pacing. The COMPANION study included patients at higher risk than those in CARE-HF and investigated three treatment limbs – optimal pharmacological therapy, biventricular pacing, and biventricular defibrillation.3 COMPANION was not powered to detect a difference in outcome between the two types of biventricular device, but did appear to show that biventricular defibrillation was superior to medical therapy based on the secondary endpoint of all-cause mortality at 12 months (Figure 5). On the basis of these trials, the ESC guidelines recommend that “CRT using biventricular pacemakers can be considered [my italics] in patients with reduced ejection fraction and ventricular asynchrony (QRS width ≥120 ms) who remain symptomatic despite optimal medical therapy (NYHA III/IV) to improve symptoms, hospitalizations, and mortality”.12 From my viewpoint, this statement may require to be updated in the revised ESC guidelines and CRT should be performed much more commonly than presently. National guidelines from the Scottish Intercollegiate Guidelines Network (SIGN), which have been more produced recently (2007) than those from the ESC (2005), make a similar statement – namely, that CRT “should be considered” in patients with characteristics similar to those described in the ESC guidelines. The English National Institute for Clinical Excellence (NICE) Health Technology Appraisal of the place of CRT in heart failure (2007) states that: “CRT with a pacing device (CRT-P) is recommended as a treatment option for patients with heart failure who fulfill the following criteria. They are currently experiencing or have recently experienced NYHA class III-IV symptoms. They are in sinus rhythm either with a QRS duration 150 ms or longer … or with a QRS duration of 120–149 ms and mechanical dyssynchrony. They have a LVEF of 35% or less. They are receiving optimal pharmacological therapy.” The NICE guidelines therefore strongly recommend CRT for a precisely defined group of patients. The NICE guidelines also offer guidance on the use of CRT with a defibrillator (CRT-D). “CRT-D may be considered for people who fulfill the criteria for implantation of a CRT-P device and who separately fulfill the criteria for use of an ICD as recommended in NICE Technology Appraisal Guidance 95.” The latter criteria include wide QRS and poor LV function post-myocardial infarction. There is controversy over whether mechanical dyssynchrony is also required for the selection of patients for CRT. Considerable heterogeneity exists in the echocardiographic criteria adopted to define dyssynchrony, but a few small observational studies suggest that echocardiographic measurement of mechanical dyssynchrony may best identify patients who are likely to benefit from CRT.7 Further work is required in this area. What are the cost implications of using CRT-P and CRT-D? Based on data from the CARE-group using data from COMPANION, the incremental cost-effectiveness of CRT-P versus medical therapy was €7538 per quality-adjusted life-year (QALY), and the incremental cost-effectiveness of CRT-D versus CRT-P was €47 909.13 CRT-P was concluded to be relatively inexpensive, while CRT-D was of borderline cost-effectiveness. The patient's age comes into consideration in deciding who, among eligible patients, should receive CRT-D. In younger patients, CRT-D may be considered affordable in order to keep patients alive for as long as possible. In patients aged above 70 years, by contrast, other factors are more likely to cause death and the cost of CRT-D compared to CRT-P becomes prohibitive. The use of CRT in patients with atrial fibrillation (AF) is a contentious issue. The ESC guidelines do not specify a rhythm, but most other guidelines do specify the presence of sinus rhythm (SR) in their recommendations. Most trials have included only patients in SR, although the MUSTIC study included approximately equal numbers of patients in SR and AF. In MUSTIC, patients in SR improved significantly, whereas those in AF did not.4,8 For patients in SR, activation of the pacemaker was associated with an improvement in 6-min walking distance, which worsened when the device was inactivated. However, it is notable that only 37 of 64 patients in AF completed both limbs of the study. A long-term follow-up of patients in MUSTIC at 9 and 12 months found that all SR patients and 88% of AF patients were programmed to biventricular pacing.9 The two groups experienced similar magnitudes of improvement in walking distance, peak VO2, quality of life, NYHA class, and ejection fraction (Figure 6). Therefore, for every factor measured, AF patients appeared to do as well as SR patients in the long term. MUSTIC and some smaller studies represent the only trial evidence on which to base treatment in patients with AF. This raises the question of whether the potential benefits of CRT should be denied to AF patients in the absence of large-scale randomized studies. Opinions obtained from members of the Heart Rhythm UK suggest that most large centers are implanting CRT devices in a proportion of AF patients. There are two schools of thought on the type of AF patient who may benefit from CRT. In one school, CRT should be offered to the relatively small numbers of patients in whom rigorous rate control can be achieved by medical therapy and, if necessary, ablation of atrioventricular conduction to ensure biventricular pacing all of the time. According to the results of MUSTIC, this group may improve. This is called the “rate control” group. In the second school of thought, patients should be selected in whom stringent efforts will be made to restore and maintain SR. CRT may help by increasing the ejection fraction, lowering mitral regurgitation, and lowering left ventricular pressure. Cardioversion will be easier, and amiodarone and atrial catheter ablation may be added. This is called the “rhythm control” group. It is clear that the rate control group and the rhythm control groups encompass almost all patients with AF who fit CRT criteria. In other words, there is little agreement on which patients not to implant. Another controversial area is that, in every trial, there are patients classified as “non-responders”, who represent approximately 40% of the study population. In a proportion of these cases, however, the CRT device is stabilizing the patient who would otherwise deteriorate. Although the patient may complain of not feeling better, the device may actually be preventing deterioration or death. This situation illustrates the difficulty in measuring response. Other indices may need to be assessed, such brain natriuretic peptide levels, echocardiography/magnetic resonance imaging, and evidence of dyssynchrony, in order to identify patients who will benefit from CRT. CRT-D is an option in younger patients, especially those considered for future transplantation, while CRT-P may be provided in older patients to improve symptoms and reduce hospitalization. CRT-D may be considered in the presence of risk factors for sudden death, such as non-sustained ventricular tachycardia (VT) or T-wave alternans. The role of CRT-D in Class IV heart failure and AF requires clarification. Controversies that relate particularly to the use of implantable cardioverters-defibrillators (ICDs) include the identification of which patients will benefit from an ICD or from a CRT plus an ICD, whether the trial evidence for coronary artery disease can be extrapolated to dilated cardiomyopathy (DCM), and issues of deactivation at end of life. The ESC guidelines state that: “Implantation of an ICD in combination with biventricular pacing can be considered (my italics) in patients who remain symptomatic with severe heart failure (NYHA class III/IV) with LVEF [left ventricular ejection fraction] ≤35% and QRS duration >120 ms to improve morbidity or mortality”. “ICD therapy is recommended (my italics) to improve survival in patients who have survived cardiac arrest or who have sustained VT, which is either poorly tolerated or associated with reduced systolic LV function.” “ICD implantation is reasonable (my italics) in selected symptomatic patients with LVEF <30–35%, not within 40 days of a myocardial infarction, on optimal background therapy … to reduce sudden death.” The largest trial that has provided evidence to substantiate these statements is SCD-HeFT.1 SCD-HeFT randomized 2500 patients with symptomatic heart failure (NYHA II/III) and LVEF <35% to no antiarrhythmic therapy, amiodarone, or ICD with a 5-year follow-up. One half of the patients had an ischaemic etiology and one half had idiopathic DCM. Patients were relatively young (mean 60 years) and a proportion were overweight (mean 85 kg). Background medication use with an ACE inhibitor or angiotensin receptor blocker and beta-blocker was good, with rates approaching 90% and 80%, respectively, and use of spironolactone (31% at last follow-up) was reasonable. Loop diuretics were prescribed in the majority. Annual mortality over 5 years was 7.2% in the placebo group. Amiodarone had no influence on morality (hazard ratio [HR] 1.06. P = 0.529 vs placebo), but ICD significantly reduced the mortality rate (HR 0.77, P = 0.007 vs placebo) (Figure 7). Analysis of subgroups showed that the HR of mortality for ICD versus placebo was 0.54 in patients with NYHA II and 1.16 in those with NYHA class III, indicating that patients with Class II heart failure benefited while those with Class III tended to fare worse. Patients with an ischaemic or non-ischaemic etiology had HRs of 0.79 and 0.73, respectively, suggesting equal benefit from ICD. Further subgroup analyses indicated that patients with a low EF (≤30%) had the most to gain (HR 0.73, vs 1.08 for those with an EF >30%), as did those on beta-blocker therapy (HR 0.68, vs 0.92 for those not on beta-blocker therapy), which emphasizes that ICD therapy is not a substitute for good medical therapy. There have been problems in interpreting the outcomes of studies such as SCD-HeFT and MADIT-II.10 The reliance on subgroup analyses in these trials has reduced the power of these studies. Inaccuracies in measurement utilizing LVEF cutoff values and NYHA class has further hampered interpretation, and the relationship between the severity of the condition and the magnitude of improvement requires clarification. No “evidence base” exists on which to guide practice at end of life. Discussing these issues with the patient and relatives is difficult, but needs to be done openly and with sensitivity if any crisis or deterioration develops. Booklets and websites are a valuable source of information that patients can choose to look at, and base decisions on, at their own pace. In the UK, information for patients on websites is available from the British Heart Foundation (www.bhf.org) and the Arrhythmia Alliance (www.arrhythmiaalliance.org.uk). Primary prevention ICDs may be considered in stable heart failure patients who are already receiving optimal medical therapy. ICD should not be considered as a substitute for medical therapy. Ischaemic and non-ischaemic patients benefit equally from ICD, and the worse the LV function, the greater is the benefit. ICD may be considered as a bridge to transplant or, alternatively, as a means to keep the patient away from transplant.

Atrial fibrillation (AF) and congestive heart failure (CHF) are the most prevalent types of cardiovascular disorders as the leading cause of death due to delayed diagnosis. Early diagnosis of these cardiac conditions is possible by manually analyzing electrocardiogram (ECG) signals. However, manual diagnosis is complex, owing to the various characteristics of ECG signals. An accurate classification system for AF and CHF has the potential to save patient lives. Therefore, this study proposed an ECG signal classification system for AF and CHF using a one-dimensional convolutional neural network (1-D CNN) to provide a robust classification system performance. This study used ECG signal recording of AF, CHF, and NSR, which can be accessed on the Physionet website. A total of 5600 ECG signal segments were obtained from 56 subjects, divided into train sets from 42 subjects (N = 4200 ECG segments), and test sets from 14 subjects (N = 1400). We applied for leave-one-out cross-validation in training to select the best model. The proposed 1-D CNN algorithm successfully classified raw data of ECG signals into normal sinus rhythm (NSR), AF, and CHF by providing the highest classification accuracy of 99.643%, f1-score, recall, and precision of 0.996, respectively, with an AUC score of 0.999. The results showed that the proposed method extracted the ECG signal information directly without needing several preprocessing steps and feature extraction methods that potentially reduce the information contained in the ECG signals. Furthermore, the proposed method outperformed previous studies in classifying AF, CHF, and NSR. Therefore, this approach can be considered as an adjunct for medical personnel to diagnose AF, CHF, and NSR.

Atrial fibrillation (AF) is common and highly variable in its clinical presentation and evolution. Iit causes substantial morbidity and mortality, including impaired quality of life, heart failure, systemic emboli, and stroke. An accurate diagnosis is important and should be distinguished from atrial flutter or other arrhythmias which involves the atrium. Management of patients with AF involves 3 objectives: rate control, rhythm control, and prevention of thromboembolism. A rate control strategy alone, without attempts at restoration or maintenance of sinus rhythm (SR), is reasonable in some patients with AF, especially those who are asymptomatic. In some circumstances, when the cause of AF is reversible, such as when AF occurs after cardiac surgery, no long-term therapy may be necessary. The CHADS2 scoring system can be used to risk stratify patients with nonvalvular AF to determine the need for warfarin. The risk of thromboembolism or stroke does not differ between pharmacological and electrical CV. Ablation of the AV conduction system and permanent pacing is an option for patients with rapid ventricular rates despite maximum medical therapy. However, there is growing concern about the negative effects of long-term RV pacing. Biventricular pacing may overcome many of the adverse hemodynamic effects associated with RV pacing. Pharmacological therapy to maintain SR should be considered in patients who have troublesome symptoms. Drugs should be used to decrease the frequency and duration of episodes, and to improve symptoms. AF recurrence while taking an antiarrhythmic drug is not indicative of treatment failure and does not necessitate a change in antiarrhythmic therapy. Antiarrhythmic drug choice is based on side effect profiles and the presence or absence of structural heart disease, heart failure, and hypertension. Catheter ablation for AF is currently considered a second-line therapy in highly symptomatic patients in whom one or more antiarrhythmic agents have failed. (J Karadiol Indones. 2010;31:187-95) Keywords: Atrial fibrillation, rate control, rhythm control, thromboembolisme, stroke, anticoagulation

Research using random forest hyperparameter optimization in the case of acute coronary syndrome allows us to obtain a more optimal prediction model, but we can find a gap assumption where the learning carried out by the model still shows symptoms of over-fitting, characterized by a fairly large gap between the training and cross-training processes. validation in the model evaluation process. The research that will be carried out will provide a more optimal prediction model and will not produce symptoms of overfitting of the model using optimization techniques for the hyperparameters in the random forest algorithm. After carrying out various scenarios and testing accuracy, precision scores and various combinations of hyperparameters in the random forest algorithm, it was concluded that the model with the best optimization had a split ratio of 90:10 with an accuracy level of 84.44%, a precision score of 85, 29% and an MSE score of 0.1556 with the results of a combination of random forest optimization hyperparameters using gridCV. The optimization model using random grid cross validation that was built succeeded in reducing the level of over-fitting in the data, decreasing the MSE (mean squared error) from 0.17 and 0.24 to 0.15 for each model.

Patients with heart failure (HF) in sinus rhythm (SR) experience an increased incidence of thromboembolic events including stroke. Among patients with HF, high-quality evidence supports the use of oral anticoagulation when atrial fibrillation is present, but the benefit of anticoagulation in SR in the absence of other known indications for anticoagulation is unclear. In four randomized controlled trials (RCTs), warfarin did not improve a composite of clinical outcomes compared with aspirin or placebo in patients with HF with reduced ejection fraction (HFrEF) and SR. A recent RCT assessed the efficacy of the direct oral anticoagulant rivaroxaban versus placebo in patients with HFrEF (including mildly reduced ejection fraction), SR, and coronary artery disease. While rivaroxaban had a neutral effect on the primary composite outcome of myocardial infarction, stroke, or all-cause mortality, exploratory analyses revealed a significant reduction in strokes. It is thus possible that a subgroup of patients with HFrEF who are at high risk of stroke may benefit from anticoagulation. The challenge is to adequately identify this subgroup and to balance the potential benefit of anticoagulation with the risk of major bleeding. There is also an unmet need for evidence around anticoagulation in HF with preserved ejection fraction and SR. This review explores the current evidence around anticoagulation in patients with HF and SR, identifies challenges regarding outcome definitions and patient selection, and offers suggestions for future research.

Tachycardia induced cardiomyopathy (TIC), secondary to various tachyarrhythmias, is a reversible condition which can lead to cardiac enlargement and heart failure. The impairment of both structure and function of heart can be reverted completely or partially if tachyarrhythmias are ceased without delay. This study aimed to explore the clinical characteristics, therapeutic regimen and outcome of TIC in children. Clinical data of 12 children with TIC, who came from Peking University First Hospital from Feb. 2003 to Jun. 2009, were retrospectively analyzed and followed up. The echocardiogram data on admission were compared with those from 12 homochronous cases with idiopathic dilated cardiomyopathy matched with 12 TIC cases in age and gender. Atrial tachycardia is the commonest arrhythmia in 12 TIC cases (75%). Four cases underwent catheterization for radiofrequency ablation and all succeeded. The cardiac rhythm of 6 out of 8 cases treated with drugs became sinus rhythm after 3 days to 2 weeks antiarrhythmic drugs treatment. The remaining 2 cases still retained atrial rhythm, but the ventricular heart rates declined to normal. The left ventricular end-diastolic dimensions of the 12 cases were decreased compared with those of pretherapy [(37.5 ± 5.3) mm vs. (43.0 ± 5.7) mm, P < 0.01], and the left ventricular ejection fractions were increased [(60.5% ± 5.6%) vs. (33.7% ± 10.3%), P < 0.01], after (3.4 ± 2.3) months. In our (4.3 ± 2.4) year-follow-up, all cases were fine, except in one case the tachyarrhythmia relapsed because of discontinuation of the drug treatment by her parents. The left ventricular end-diastolic dimensions in 12 TIC cases were smaller than those of the 12 age- and gender-matched idiopathic dilated cardiomyopathy [(43.0 ± 5.7) mm vs. (54.8 ± 7.5) mm, t = 7.9, P < 0.01], and the ejection fractions were higher [(33.7% ± 10.3%) vs. (21.8% ± 7.5%), t = 3.7, P < 0.01]. The diagnosis of TIC should be considered for the children with tachycardia, cardiac enlargement and cardiac insufficiency. The degree of cardiac enlargement and cardiac insufficiency might be of value for the differential diagnosis between TIC and idiopathic dilated cardiomyopathy. The rhythm control and ventricular rates control could all result in a favorite therapeutic efficacy.

Life-threatening ventricular arrhythmias (LTVA) prediction in individuals without cardiovascular disease remains a major challenge.We tested the performance of a multilayer convolutional neural network (CNN) using ECG signals, age and sex.We split 86,603 individuals from the UK Biobank study into a training (90%) and a test (10%) set.In the training set, we trained a multilayer CNN using 15-second ECGs at rest from lead I, age and sex as inputs.The output was the probability of LTVA within a 12-year follow-up.The CNN model consisted of a fourlayer CNN (128, 128, 256 and 256 channels, kernel sizes of 3) and a single attention layer.Age and sex were included as external inputs to the final layer.In the test set (0.9% LTVA events), the CNN's prediction led to a median AUC of 0.601, and a specificity of 0.287 for a sensitivity of 0.750.We set a threshold at the CNN's prediction value maximising the sum of specificity and sensitivity in the training set.Survival analyses showed a hazard ratio (HR) of 1.396 (P = 0.021) for individuals with a CNN's prediction value > threshold, versus those with a CNN's prediction value < threshold.A multilayer CNN model using 10-second ECG data from lead I, together with information on age and sex, can stratify individuals at risk of LTVA.Our findings support the potential utility of wearables for accessible screening in the general population.

Introduction Heart failure (HF) and atrial fibrillation (AF) are increasingly prevalent and associated with substantial morbidity (1,2). When HF and AF co-exist, the outcome profile is significantly worse than for either condition in isolation (3). Ethnic background is known to influence disease outcomes and treatment efficacy (4), but there is limited knowledge about how HF, AF and ethnicity interact on mortality and hospital admission. Purpose This study aims to address the null hypothesis of no difference in death and cardiovascular events comparing non-white and white patients with HF and concomitant AF, and assess the differential impact of ethnicity in patients with these conditions. Methods Individual patient data were obtained from 12 randomized controlled trials (RCTs) in patients with HF. RCT data were harmonised and meta-analysed to investigate the interaction of baseline heart rhythm (sinus rhythm versus atrial fibrillation) and ethnicity (non-white versus white). The primary outcome of all-cause mortality and secondary outcome of cardiovascular (CV)-related mortality were analysed using adjusted Cox regression models and propensity-score matching. Results 16,713 HF patients were included of which 1,899 (11%) were non-white, median age 66 (interquartile range [IQR] 57-73) and 4,703 (28%) women. During median follow-up of 1.4 years (IQR 0.8-2.3), death occurred in 394 (21%) non-white patients and 2,142 (15%) white patients; adjusted hazard ratio (HR) 1.36, 95% CI 1.20-1.54; p&amp;lt;0.001. The impact of ethnicity was greater in patients with coexisting HF and AF (non-white versus white HR 2.05; 95% CI 1.55-2.70; p&amp;lt;0.001), than in those with HF in sinus rhythm (non-white versus white HR 1.24; 95% CI 1.08-1.41; p=0.002). A significant interaction was evident between ethnicity and rhythm status for all-cause mortality (p=0.003), with similar findings using propensity-score matching (Figure 1). An exploratory analysis of beta-blockers versus placebo demonstrated divergent efficacy with respect to mortality for non-white (HR 1.00, 95% CI 0.79-1.27; p=0.99) and white patients (HR 0.70, 95% CI 0.63-0.78; p&amp;lt;0.001); p-interaction=0.008 (Figure 2). For cardiovascular hospitalisation, the non-white cohort also had higher rates, with greatest disparity in patients with combined HF and AF (non-white versus white HR 1.80, 95% CI 1.63-2.37; p&amp;lt;0.001) compared to HF in sinus rhythm (non-white versus white HR 1.23, 95% CI 1.11-1.36; p&amp;lt;0.001); p-interaction=0.012 in propensity-matching. Conclusion Non-white patients with HF suffer from substantially higher rates of death and hospitalisation than corresponding white patients, with the presence of comorbid AF significantly worsening this ethnicity-related disparity. In those with HF in sinus rhythm, beta blockers were found to be significantly less effective at reducing mortality in non-white patients.Figure 1 Figure 2

Database The efficiency and robustness of the proposed method has been tested on Fantasia Database (FTD), MIT-BIH Arrhythmia Database (MIT-AD), and MIT-BIH Normal Sinus Rhythm Database (MIT-NSD). Aim Because of the importance of QRS complex in the diagnosis of cardiovascular diseases, improvement in accuracy of its measurement has been set as a target. The present study provides an algorithm for automatic detection of QRS complex on the ECG signal, with the benefit of energy and reduced impact of noise on the ECG signal. Method The method is basically based on the Teager energy operator (TEO), which facilitates the detection of the baseline threshold and extracts QRS complex from the ECG signal. Results The testing of the undertaken method on the Fanatasia Database showed the following results: sensitivity (Se) = 99.971%, positive prediction (P+) = 99.973%, detection error rate (DER) = 0.056%, and accuracy (Acc) = 99.944%. On MIT-AD involvement, Se = 99.74%, P+ = 99.97%, DER = 0.291%, and Acc = 99.71%. On MIT-NSD involvement, Se = 99.878%, P+ = 99.989%, DER = 0.134%, and Acc = 99.867%. Conclusion Despite the closeness of the recorded peaks which inflicts a constraint in detection of the two consecutive QRS complexes, the proposed method, by applying 4 simple and quick steps, has effectively and reliably detected the QRS complexes which make it suitable for practical purposes and applications.

Heart failure is a multifactorial syndrome of hemodynamic decompensation that is a final common pathway for a variety of cardiovascular disorders. More than 40% of patients with heart failure lose their lives because of sudden cardiac death. Thus, the prevention of life-threatening cardiac arrhythmia is one of the major goals in the treatment of heart failure. The Cardiac Arrhythmia Suppression Trial (CAST) study has shown that class I antiarrhythmic agents are not clinically beneficial for long-term treatment of arrhythmias in patients with previous myocardial infarction. Although β-adrenergic blockers and amiodarone are effective in reducing arrhythmic mortality,1 the underlying mechanisms are not fully understood. Thus, development of the experimental animal models and comprehensive studies for elucidation of pathophysiological characteristics of life-threatening cardiac arrhythmias in heart failure is of fundamental importance. The electrophysiological substrates associated with life-threatening cardiac arrhythmias are varied and include impairment of conduction attributable to structural alterations, spatial and temporal inhomogeneity of action potential duration attributable to remodeling of ionic channels, and triggered activity.2 There are several studies describing changes in the functional expression of various ion channels and Ca2+-handling proteins/systems in cardiac myocytes isolated from failing hearts.3 4 In human and some animal models of heart failure, the protein level of the sarcoplasmic reticulum (SR) Ca2+ ATPase (SERCA) is reduced and that of Na+-Ca2+ exchanger (NCX) …

Treatment of Patients with Both Arrhythmias and Heart Failure

IntroductionAtrial fibrillation may potentially contribute to oxidative stress to a greater extent than chronic heart failure. The aim of the study was to compare the serum total antioxidant capacity and enzymatic antioxidant defence of dogs with chronic heart failure and atrial fibrillation with those of subjects with chronic heart failure and sinus rhythm and healthy controls.Material and MethodsA total of 33 dogs were divided into three groups: dogs with chronic heart failure and atrial fibrillation (CHF + AF; n = 12), chronic heart failure and sinus rhythm (CHF + SR; n = 9), and healthy controls (n = 12). Serum total antioxidant capacity (TAC), serum CuZn-superoxide dismutase (SOD) and catalase, and plasma glutathione peroxidase (GPx) activity were determined.ResultsSOD activity and serum TAC were significantly lower in the study groups than in control animals. Catalase activity was significantly higher and plasma GPx activity significantly lower in dogs with CHF + AF compared with the CHF + SR and control dogs.ConclusionThe results suggest that chronic heart failure in dogs significantly impacts the serum TAC and the antioxidant enzymatic defence, while plasma GPx activity is markedly lower in dogs with chronic heart failure and atrial fibrillation. The role of that imbalance needs further investigation.

Background Digoxin is one of the oldest drugs used in heart failure treatment. It is recommended in patients in sinus rhythm with still symptomatic heart failure with reduced ejection fraction. However, a controversy regarding digoxin use has risen with recent studies demonstrating an increased mortality and arrhythmias rate in patients taking this drug. Purpose The purpose of this study is to assess the prognostic impact of digoxin in patients in sinus rhythm with a CRT device, concerning all-cause mortality, hospitalizations due to acute heart failure and rate of ventricular arrhythmias. Methods A cohort of 297 consecutive P with advanced HF, sinus rhythm and a CRT device (80% with defibrillator) implanted between February 2004 and January 2016, in a single centre, was included in this retrospective study. Patients were divided in two groups regarding digoxin prescription (digoxin (DG) and without digoxin (NDG)). A mean clinical follow-up of 5.3 ± 3.4 years regarding long term outcomes was performed. Cox regression was used to identify independent predictors of outcomes. Results Digoxin was prescribed in 104 P (35%). In this cohort 67% of P were males and the mean age was 64 ± 11 years. Patients in DG were younger (60 ± 11 vs 66 ± 10, p &amp;lt; 0.001). The 2 groups had similar prevalence of comorbidities, with exception of chronic kidney disease (GD 27.5% vs GND 33.3%, p = 0.05). The etiology was similar between the 2 groups (42% ischaemic). In the qui-square analysis, there was a statically significant association between the use of digoxin and mortality (DG 42.3% vs NDG 25.4%, p= 0.003), and also between digoxin and hospitalization with acute heart failure (DG 36.5% vs NDG 21.4%, p = 0.005). There was no association between digoxin use and the occurrence of ventricular tachycardia (DG 31.7% vs 40.1%, p = 0.155). In the Cox proportional hazards regression, accounting for the potential confounders, the use of digoxin was an independent predictor for all-cause mortality (HR = 2.80, CI 95 [1.07 – 7.31], p = 0.036) and also for hospitalization with acute heart failure (HR = 5.82, CI 95 [1.54 – 22.06], p = 0.010). Conclusion The use of digoxin was an independent predictor of all-cause mortality and hospitalizations due to acute heart failure. Randomized trials are needed to clarify the impact of digoxin and determine if it is only an indicator of disease severity and worse prognosis or if the drug has a direct negative influence in the natural history of P with heart failure. Abstract Figure.