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.
The ultra rapid potassium current (IKur) is an attractive pharmacological target in atrial fibrillation (AF) management due to its atrial specific nature. An experimentally based 78% IKur reduction was incorporated into a human atrial action potential (AP) model under sinus rhythm (SR) and atrial fibrillation (AF) conditions. Its effects on cell and tissue level electrical activity were simulated...
Functional roles of ionic currents in a membrane delimited sino-atrial node (SAN) cell model were investigated. Ionic currents were blocked and intracellular calcium ([Ca2+]i) buffered to study their effects on action potential (AP) characteristics. The simulations revealed that blocking the hyperpolarization activated current and the T-type calcium current caused an increase of cycle length (CL)...
To investigate complex electrophysiological behaviour (such as reentrant cardiac arrhythmias) in the setting of the complex anatomy of the heart, the use of a simplified model is computationally more effective. In this study, the Rogers-modified FitzHugh-Nagumo model was further modified to allow control of action potential upstroke velocity, conduction velocity, action potential duration and refractory...
Cardiac rhythm is irregular with heart rate varies from time to time. Heart rate variation (HRV) is clinically relevant and indicative of a pathological condition. However, the mechanisms underlying the HRV are still controversial and stochastic nervous modulation may be a major responsible factor. In this study, we implemented a computer simulation study to investigate a causative link between stochastic...
Atrial fibrillation (AF) is commonly associated with rapid excitation of the atria, but mechanisms of its initiation are unknown. Intracellular Ca2+ dynamics has been shown to affect cell restitution properties and, as a result, patterns of rapid reentrant excitation in ventricles at early stages of ventricular fibrillation. We study effects of the intracellular Ca2+ concentration changes on restitution...
Experimentally observed differences in the action potential (AP) properties - primarily, refractoriness - between the left (LA) and right (RA) atria are believed to be important in maintaining atrial fibrillation (AF). However, relationships between the underlying ionic differences in the LA and RA cells, as well as their impacts on the tissue refractoriness and susceptibility to AF are unknown. We...
This paper attempts to make use of brain computer interface (BCI) in implementing an application called the media communication center for the paralyzed people. The application is based on the event-related potential called P300 to perform button selections on media and communication programs such as the mp3 player, video player, photo gallery and e-book. One of the key issues in such system is the...
The electrocardiogram (ECG) is an important index of clinical diagnosis of cardiac arrhythmias. Simulations of ECG had revealed the causative relationship between waveforms of ECG and action potentials (APs). However, those studies were mainly based on the Luo-Rudy (LRd) model or the Priebe-Beuckelman (PB) model. In this study, we developed a ID model of transmural ventricular strand based on the...
Heart failure (HF) induces remodeling in cellular ionic channel kinetics and calcium handling in the ventricle. In the present study, we investigated the effects of HF on rate dependent electrical activity of human ventricular myocytes by characterizing the dynamic action potential duration restitution (APDr), action potential (AP) alternans, intracellular calcium transient ([Ca2+]i) alternans, and...
Atrial arrhythmias (flutter and fibrillation) are characterised by rapid and irregular activation of atrium. There are two possible mechanisms: abnormal spontaneous electrical activity of ectopic foci and multiple reentrant wavelets. In this study, we developed a biophysically detailed computer model of virtual human atrium to study the interaction between the two major arrhythmic origins. Depending...
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.