The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Mapping of cardiac electrical activity from Langendorff-perfused hearts using the voltage-sensitive dye (VSD) di-4-ANEPPS has yielded important new information. However, data about response of the heart to staining with VSD are scarce. Voltage-sensitive dye di-4-ANEPPS is currently used in our laboratory for recording of monophasic action potentials by optical method in isolated hearts. The most often...
This study aimed to provide quantitative clinical data on the comparison of the effect of talking on both manual and automatic blood pressure (BP) measurements. Manual auscultatory systolic and diastolic blood pressures (SBP and DBP) were obtained from 20 healthy subjects under resting and talking conditions. During the measurement the oscillometric cuff pressure was also recorded digitally. Manual...
Emotion is the complex psychophysiological experience of an individual's state of mind as interacting with environmental influences. In this paper, we try to find the relation between colors, emotions and heart response using Triangular Phase Space Mapping (TPSM), a novel method for representation of heart rate. We used four colors as a visual stimulus while the lead II of ECG was recorded from 16...
T-wave alternans (TWA) has been linked to increased vulnerability of the myocardium to ventricular fibrillation in different clinical conditions. Our aim in this work was to study and characterize TWA in an animal model of myocardial ischemia and infarction. Infarction was induced in 29 pigs by a 40-minute-long balloon inflation on the left anterior descending coronary artery. The occlusion recording,...
Premature Ventricular Contraction (PVC) can occur in healthy people of any age and is linked to mortality when associated with myocardial infarction. There has been voluminous research that focuses on PVC detection. However, pre-processing techniques such as wavelet filtering may cause delay by extracting features on frequency domain rather than time domain. Furthermore, many classifiers are only...
Traditional entropy measures, such as Approximate Entropy (ApEn) and Sample Entropy (SampEn), are widely used for analyzing heart rate variability (HRV) signals in clinical cardiovascular disease studies. Nevertheless, traditional entropy measures have a poor statistical stability due to the 0–1 judgment of Heaviside function. The objective of this study is to introduce a new entropy measure — Fuzzy...
Data acquirement and signal processing at Multi-parameter records such as PhysioNet database records require accessing records remotely, laying out uncertain number of parameters, and doing conjunct analysis. This paper proposes developing software by QT graphical C++ toolkit can meet the requirements described above in less developing time and higher efficiency. Practical works at a software tool...
Ambulatory blood pressure monitoring (ABPM) devices provide 24-hour profiles of mean arterial pressure (MAP) and heart rate (HR) by inflating an arm-cuff every 15 minutes during daytime and every 20 minutes during night-time. Aim of this work is to evaluate whether the intrinsic structure of ABPM dynamics can be described during day and night subperiods by calculating the fractal dimension (FD) of...
In response to the PhysioNet/CinC Challenge 2011: Improving the quality of ECGs collected using mobile phones we have developed an algorithm based on a decision support system. It combines couple of simple rules — in order to discard recordings of obviously low quality (i.e. high-amplitude noise, detached electrodes) with more sophisticated support vector machine (SVM) classification that deals with...
Impedance cardiography senses the variation in the thoracic impedance caused by variation in the blood volume and it is used for estimating the stroke volume and other cardiovascular indices. Respiratory and motion artifacts in the sensed signal introduce errors in these estimations. A denoising technique, using discrete Meyer and symlet-26 wavelets, with scale-dependent thresholding for suppressing...
This study aimed to assess the accuracy of current ECG criteria for locating the coronary artery principally involved in an acute myocardial infarction (AMI) in order to evaluate the merits of implementing AHA/ACC recommendations that require the culprit artery be reported on an ECG interpretation. 12 lead ECGs were recorded in ambulances on patients with a suspected acute coronary syndrome. These...
The upgrade of mobile phones with applications for acquisition, pre-processing and transmitting the patient's ECG to a hospital unit would be of great benefit for prevention against the most frequent mortality caused by heart failure. This idea is promoted by the Computing in Cardiology Challenge 2011, which encourages the development of algorithms for analysis of the ECG quality within few seconds,...
We describe a data-driven approach, using a combination of machine learning algorithms to solve the 2011 Physionet/Computing in Cardiology (CinC) challenge — identifying data collection problems at 12 leads electrocardiography (ECG). Our data-driven approach reaches an internal (cross-validation) accuracy of almost 93% on the training set, and accuracy of 91.2% on the test set.
In this study we present a vectorcardiographic method to identify the culprit artery in acute coronary syndrome (ACS) in a study population of 860 patients with single vessel disease who underwent percutaneous coronary intervention (PCI). This method takes, in addition to the classical STEMI definition of J point elevation > 100 μV, also features of the QRS complex and the T wave into account....
“Early repolarisation” has generally been considered benign until recently when it has been associated with life threatening arrhythmias. Because there has been confusion around defining J point elevation in relation to early repolarisation, this study examined ECGs recorded from an apparently healthy adult Caucasian cohort of males and females. As first step, the prevalence of end QRS notching, end...
We hypothesized that not only the location but also extent of myocardial ischemia (area at risk, AAR) during acute myocardial infarction could be estimated from the spatial distribution of ST-segment deviations in the ECG. Standard 12-lead ECGs and SPECT images were obtained from 75 patients. Precordial ST-segment deviations were organized according to spatial orientation. An ST-profile was obtained:...
An algorithm to determine quality of ECGs can enable inexperienced nurses and paramedics to record ECGs of sufficient diagnostic quality. We propose an algorithm that can assess the quality of an ECG designed for an Android-based platform. The algorithm is based on previously established ECG quality metrics for quantifying ECG quality but designed in a way to make it efficient to run on a mobile platform...
Although the Body Surface Potential Map (BSPM) is considered to be an improved technique for the detection of cardiac pathologies when compared to the 12-lead electrocardiogram (ECG), it has not been adopted for routine clinical practice. This is partly due to a lack of clinician-friendly tools for visualizing the large amount of data a BSPM contains. This work presents the details of a usability...
Heart failure (HF) is a kind of serious cardiovascular diseases, leading to an increasing burden imposed on public healthcare. Early diagnosis and proper treatment of HF are essential to reducing its morbidity and mortality. In spite of the implementation of clinical guidelines for HF, early recognition and stratification of HF risk remain unsolved. In this work, we supposed a computational model...
We estimate that as much as 5% of all recorded ECGs worldwide may, to some degree, suffer from poor signal quality or incorrect electrode positioning, which often interferes with correct interpretation of the ECG. Proper training of ECG technicians and regular inspection of signal quality is necessary to achieve a high standard. Due to the large amounts of ECGs recorded daily, we devised an automatic...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.