Diagnosis Of Ventricular Fibrillation Research Articles

Detection of Ventricular Fibrillation Using Ensemble Empirical Mode Decomposition of ECG Signals

Ventricular fibrillation (VF) is a critical ventricular arrhythmia with severe consequences. Due to the severity of VF, it urgently requires a rapid and accurate detection of abnormal patterns in ECG signals. Here, we present an efficient method to detect abnormal electrocardiogram (ECG) signals associated with VF by measuring orthogonality between intrinsic mode functions (IMFs) derived from a data-driven decomposition method, namely, ensemble empirical mode decomposition (EEMD). The proposed method incorporates the decomposition of the ECG signal into its IMFs using EEMD, followed by the computation of the angles between subsequent IMFs, especially low-order IMFs, as the features to discriminate normal and abnormal ECG patterns. The proposed method was validated through experiments using a public MIT-BIH ECG dataset for its effectiveness in detecting VF ECG signals compared to conventional methods. The proposed method achieves a sensitivity of 99.22%, a specificity of 99.37%, and an accuracy of 99.28% with a 3 s ECG window and a support vector machine (SVM) with a linear kernel, which performs better than existing VF detection methods. The capability of the proposed method can provide a perspective approach for the real-time and practical computer-aided diagnosis of VF.

Incidence of life-threatening events in children with Wolff-Parkinson-White syndrome: Analysis of a large claims database.

Previous estimates of life-threatening event (LTE) risk in Wolff-Parkinson-White (WPW) syndrome are limited by selection bias inherent to tertiary care referral-based cohorts. This analysis sought to measure LTE incidence in children with WPW syndrome in a large contemporary representative population. A retrospective cohort study was conducted using claims data from the IBM MarketScan Research Databases, evaluating subjects with WPW syndrome (age 1-18 years) from any encounter between January 1, 2013, and December 31, 2018. Subjects with congenital heart disease and cardiomyopathy were excluded. The primary outcome was diagnosis of ventricular fibrillation (VF); a composite outcome, LTE, was defined as occurrence of VF and/or cardiac arrest. VF and LTE rates were compared to matched representative controls without WPW syndrome (3:1 ratio). The prevalence of WPW syndrome was 0.03% (8733/26,684,581) over a median follow-up of 1.6 years (interquartile range 0.7-2.9 years). Excluding congenital heart disease/cardiomyopathy, 6946 subjects were analyzed. An LTE occurred in 49 subjects (0.7%), including VF in 20 (0.3%). The incidence of VF was 0.8 events per 1000 person-years, and the incidence of LTE was 1.9 events per 1000 person-years. There were no occurrences of VF in controls; the rate of LTE was 70 times higher in subjects with WPW syndrome (0.7%; 95% confidence interval 0.5%-0.9%) than in controls (0.01%; 95% confidence interval 0%-0.02%). The use of a large claims data setallowed for an evaluation of VF and LTE risk in an unselected pediatric population with WPW syndrome. The observed range of 0.8-1.9 events per 1000 person-years is consistent with prior reports from selected populations. A comparison of event rates to matched controls confirms and quantifies the significant elevation in VF and LTE risk in pediatric WPW syndrome.

Quantification of Electromechanical Coupling to Prevent Inappropriate Implantable Cardioverter-Defibrillator Shocks.

ObjectivesThis study sought to test specialized processing of laser Doppler signals for discriminating ventricular fibrillation (VF) from common causes of inappropriate therapies.BackgroundInappropriate implantable cardioverter-defibrillator (ICD) therapies remain a clinically important problem associated with morbidity and mortality. Tissue perfusion biomarkers, implemented to assist automated diagnosis of VF, sometimes mistake artifacts and random noise for perfusion, which could lead to shocks being inappropriately withheld.MethodsThe study tested a novel processing algorithm that combines electrogram data and laser Doppler perfusion monitoring as a method for assessing circulatory status. Fifty patients undergoing VF induction during ICD implantation were recruited. Noninvasive laser Doppler and continuous electrograms were recorded during both sinus rhythm and VF. Two additional scenarios that might have led to inappropriate shocks were simulated for each patient: ventricular lead fracture and T-wave oversensing. The laser Doppler was analyzed using 3 methods for reducing noise: 1) running mean; 2) oscillatory height; and 3) a novel quantification of electromechanical coupling which gates laser Doppler relative to electrograms. In addition, the algorithm was tested during exercise-induced sinus tachycardia.ResultsOnly the electromechanical coupling algorithm found a clear perfusion cut off between sinus rhythm and VF (sensitivity and specificity of 100%). Sensitivity and specificity remained at 100% during simulated lead fracture and electrogram oversensing. (Area under the curve running mean: 0.91; oscillatory height: 0.86; electromechanical coupling: 1.00). Sinus tachycardia did not cause false positive results.ConclusionsQuantifying the coupling between electrical and perfusion signals increases reliability of discrimination between VF and artifacts that ICDs may interpret as VF. Incorporating such methods into future ICDs may safely permit reductions of inappropriate shocks.

Development of Ventricular Fibrillation Diagnosis Method Based on Neuro-fuzzy Systems for Automated External Defibrillators

The aim of this study is to develop an embedded method for automatic diagnosis of ventricular fibrillation (VF) using a neuro-fuzzy system embedded in an automated external defibrillator (AED). To diagnose VF using AEDs, we use the neural network with weighted fuzzy membership functions (NEWFM), a wavelet transform (WT), a sequential increment method (SIM), and phase-space reconstruction (PSR) in order to classify normal sinus rhythm (NSR) and VF of electrocardiogram (ECG) episodes. This study has the following key points. The first contribution is the extraction of peaks from ECG episodes by the use of the WT and SIM by a time–frequency technique. The second contribution is that NSR and VF are distinguished by means of three-dimensional (3D) PSR based on a 3D graphic model. The third contribution is the identification of feature differences between NSR and VF by the use of graphical characteristics of weighted fuzzy membership functions (WFMs) supported by the NEWFM. The final contribution is the development of a neuro-fuzzy system for automatic diagnosis of VF using the WFMs embedded in the AED. The following four preprocessing steps are implemented to extract features from ECG episodes. In the first step, the WT is used for multi-scale representation and analysis and wavelet coefficients are then generated from the ECG episodes. In the second step, the SIM is used to extract peaks from the wavelet coefficients. In the third step, successive peaks are plotted in a 3D phase-space diagram by performing 3D PSR. In the final step, the distance between the origin (0, 0, 0) and the successive peaks plotted in a 3D phase-space diagram is calculated; then, 20 features are extracted from the calculated distances using statistical methods, including frequency distributions and their variability. The 20 extracted features are applied as inputs to the NEWFM, and the result is that the classification accuracy of the NEWFM is 100 %.

Anomalous origin of right coronary artery from the left coronary sinus: sudden death and successful surgical reimplantation

A 39-year-old man with no clinical relevant data, elite long-distance runner, was admitted to our institution with the diagnosis of ventricular fibrillation while participating in a half-marathon competition. He was resuscitated at the site of the event with electrical cardioversion, and at his admission, he was clinically stable. Electrocardiogram demonstrated regular …

Moderne technische Hilfen für die kardiovaskuläre Medizin

Despite basic physiologic principles being well known for more than 300 years, the diagnosis and therapy of cardiovascular diseases are still in their early beginnings. For example, 100 years ago sudden cardiac arrest was regarded as the result of toxic gases. The diagnosis of ventricular fibrillation or treatment with a defibrillator are very recent developments. We are currently experiencing a technological revolution, which is rapidly changing cardiovascular medicine. This publication is focused on electrical devices and tries to identify some of the innovation mainstreams using a few examples to demonstrate these. Four megatrends are explained in more detail: the influence of wireless technology, information technology, micro systems technology, and thinking in systems. This paper is aimed at stimulating active researchers and engineers to detect the rapid changes that we often do not observe in our daily work. The author hopes that this stimulation will lead to new ideas and combinations.

Ventricular Fibrillation Diagnosed During Electrophysiological Study for Non-Sustained Tachycardia

Ventricular fibrillation diagnoses such as Brugada syndrome pose a risk of sudden incapacitation or death in aircrew. This case report presents a 44-yr-old male fighter pilot who unexpectedly developed ventricular fibrillation (VF) during an electrophysiological study (EPS) prior to therapy for non-sustained ventricular tachycardia (nsVT). The initial aeromedical disposition for this case was "qualified for flying duties". with the restriction that he must fly with another pilot due to repeatedly observed nsVT. This pilot wanted to return to flight duty in single-seat aircraft without any restrictions. Therefore, this patient decided to undergo catheter therapy for nsVT. Unexpectedly, not VT but VF was induced by catheter manipulation during EPS. Pilsicainide-induced coved-type ST wave elevation consistent with Brugada syndrome was noted in this patient's electrocardiogram. He was ultimately disqualified due to the diagnosis of VF. This report suggests EPS on rare occasions may uncover another severe disease similar to this case report.

Development of a severe model of early coronary artery ligation-induced dysrhythmias in the anaesthetized rat.

1. The potential use of catecholamines to increase the severity of dysrhythmias evoked by coronary artery ligation in the anaesthetized rat was investigated. Drugs were given intravenously prior to ligation. 2 Pressor doses of adrenaline (5 microgram/kg) noradrenaline (1 microgram/kg) phenylephrine (5-10 microgram/kg), and angiotensin (0.25 microgram/kg) conferred protection against the development of dysrhythmias. 3 Atropine (1 mg/kg) increased mortality from ventricular fibrilloflutter (VF) and abolished the protective effects of phenylephrine (10 micrograms/kg). 4 Administration of isoprenaline (10 microgram/kg) significantly increased the incidence of and the mortality from VF. 5 The order of antidysrhythmic drug potency of Org 6001 (1-10 mg/kg), disopyramide (2-10 mg/kg) and practolol (2-10 mg/kg) was similar in both the standard (without isoprenaline) and modified (with isoprenaline) models. 6 Use of the modified method for antidysrhythmic screening purpose allows demonstration of statistically meaningful results with the use of relatively few animals. 7 Comparison of the pattern of VF in the rat heart induced by various means suggests that the diagnosis of ventricular fibrillation can be made with more confidence in the modified method compared to the standard method.

Transitory ventricular fibrillation as a cause of syncope and its prevention by quinidine sulphate: With case report and discussion of diagnostic criteria for ventricular fibrillation

The significance and diagnosis of ventricular fibrillation is discussed with reference to a patient without evidence of organic heart disease, who had for eighteen months attacks of syncope due to transitory ventricular fibrillation. Quinidine sulphate rationing prevented these attacks.