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Beat-to-beat QT interval variability (QTV) is a marker of ventricular repolarization lability. Increased QTV has been associated ith cardiac mortality. The aim of this paper was to investigate QTV in the 12-lead ECG and the potential effect of age. Short-term ECGs (2 mins) of 48 healthy males ere studied. Beat-to-beat QTV as measured in each lead by using Berger's template-stretching algorithm. We...
Computational models of the mammalian ventricular myocyte have become important tools for understanding the biophysical basis of the ventricular action potential (AP), for relating changes in gene/protein expression and effects of gene mutations to alterations of AP and calcium transient morphology, and for investigating mechanisms of arrhythmia. We established the computational model of heart failure...
The heart consists of myocytes, vasculature cells and connective tissue cells. In this study, two ventricular electromechanical models were coupled with the fibroblast model. At the cellular level, Niederer-Smith (NS) model of rat ventricular myocyte and ten Tusscher model of human ventricular myocyte and the passive fibroblast model are combined with Rice model of contraction and cooperativity mechanisms...
An ectopic heartbeat initiated by the ventricles is considered as Premature Ventricular Contraction (PVC) beat. For any individual, unifocal PVCs are typically monomorphic, whereas multifocal PVCs have polymorph contour. The ectopic rate especially of multimorphic PVCs is significantly associated with sudden death and many other main arrhythmic events. In order to group PVCs upon their morphology,...
Background: Assessing the hemodynamic impact of an intermediate coronary artery stenosis on the basis of the diameter stenosis is often ambiguous. Measurement of the fractional flow reserve (FFR) is necessary in these cases for correct clinical decision making. Aim: Determining the tranlesional pressure gradients, based on the data calculated from the 3D coronary angiography and the frame count method...
Many kinds of methods have been developed to classify QRS complex in Holter electrocardiogram. However, the accuracy of these methods dose not fully satisfy the clinical needs. In this paper, we developed an automated classification methods using a wavelet transform and two-layered Self-Organizing Map (SOM) to improve the accuracy. A discrete wavelet coefficient is used as a characteristic parameter...
The electrocardiogram (ECG) is a diagnostic tool that measures and records the electrical activity of the heart in exquisite detail. Interpretation of these details allows diagnosis of a wide range of heart conditions. Automatic extraction of time plane features is important for cardiac disease diagnosis. This paper presents a multi-resolution wavelet transform based system for detection and evaluation...
ECG signals can be seriously distorted by Power-Line Interference (PLI), the electromagnetic interference of power-line cables. This contamination can lead to imprecise measurements of the ECG wave durations and amplitudes. Therefore, the accuracy of the ECG analysis can be significantly reduced. The aim of this study was to develop and test a PLI detection algorithm, including the automatic recognition...
Virtual histology modality uses in-depth analysis of the backscattered RF-signal in order to provide a detailed description of the atheromatous plaque composition. The amount of one type of tissue (Necrotic Core) which is confluent is an important marker in diagnosis of various medical conditions. Confluent plaque that borders the Lumen is medically relevant (TCFA, CaTCFA). Measurements of the plaque...
A method for respiratory signal estimation from the pulse photoplethysmographic (PPG) signal is presented. The method is based on combination of three parameters present in this signal: pulse rate variability, pulse amplitude variability and pulse width variability. Evaluation is performed over a database containing electrocardiographic (ECG), PPG and respiratory signals simultaneously recorded in...
Remote follow-up of implanted ICD's offers a solution to the problem of overcrowded clinics. All major device companies have developed a remote follow-up solution. Data from the remote follow-up are stored in a central database system, operated by the device company and accessible for the physician. However, the problem now arises that part of the patient's clinical information is stored in the local...
Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) represent a potential valuable alternative to human embryonic stem cell-derived cardiomyocytes (hESC-CMs) for the lack of ethical issues and their patient-specificity. Recent studies showed hiPSC-CMs behave like hESC-CMs in terms of membrane currents, contractility and frequency of spontaneous pacing but their similarities need...
This study presents a system that enables the incorporation of similarity knowledge extracted from the Cardiovascular Gene Ontology (CGO) into cardiovascular research. The implementation of the system is based on the combination of biological function annotations provided by the CGO for more than 4000 genes associated with cardiovascular processes and topological features encoded in the Gene Ontology...
An algorithm has been developed for a Public Access Defibrillator which utilizes distinctive features from the impedance cardiogram (ICG) recorded via defibrillator pads to advise both lay users and minimally trained bystanders to ensure CPR effectiveness. Following ethical approval, data were collected and marked. CPR was administered by trained personnel. 211 cases were gathered and the training...
In cardiology departments supporting implantation and follow-up of Cardiovascular Implantable Electronic Devices (CIED), relevant clinical data reside in autonomous healthcare information systems that support different health information technology (HIT) standards and proprietary data formats. Each organization chooses the Electronic Health Record (EHR) integration solutions, underlying technologies,...
A new Anesthesia Information Management System has been developed at Heart Hospital of G. Monasterio CNR — Tuscany Region Foundation in Massa. It is specialized in recording anesthesia-related perioperative patient data during cardiac surgery on either adult or pediatric patients. The system was aimed at integrating all patient data partly filled in by the operator, partly SQL-retrieved from the Hospital...
The cancellation of ventricular activity (VA) from atrial electrogram (AEG) is commonly performed by template matching and subtraction (TMS): a running template, built by adaptive averaging of AEG segments in correspondence of QRS, is subtracted from AEG to uncover atrial activity (AA). In our approach, before subtraction, templates are modulated by a set of coefficients which are estimated by maximizing,...
Electrocardiographic wave forms during the QRS interval reflect the activation sequence of the heart. This can be demonstrated in ECGSIM, an interactive software package aimed to support ECG education and research. When using this package, the timing of activation may be changed interactively, either locally or globally. The resulting QRS changes are displayed instantaneously. We describe a new feature...
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