1,348 research outputs found
三次元心臓モデルと不均一振動モデルによる心臓活動電位のコンピュータシミュレーション
Tohoku University西條芳文論
FROM CARDIAC OPTICAL IMAGING DATA TO BODY SURFACE ECG: A THREE DIMENSIONAL VENTRICLE MODEL
Understanding the mechanisms behind unexplained abnormal heart rhythms is important for diagnosis and prevention of arrhythmias. Many studies have investigated the mechanisms at organ, tissue, cellular and molecular levels. There is considerable information available from tissue level experiments that investigate local action potential properties and from optical imaging to observe activity propagation properties at an organ level. By combining those electrophysiological properties together, in the present study we developed a simulation model that can help in estimation of the resulting body surface potentials from a specific electrical activity pattern within the myocardium. Some of the potential uses of our model include: 1) providing visualization of an entire electrophysiological event, i.e. surface potentials and associated source which would be optical imaging data, 2) estimation of QT intervals resulting from local action potential property changes, 3) aiding in improving defibrillation therapy by determining optimal timing and location of shocks
Multiscale Modeling of the Ventricles: From Cellular Electrophysiology to Body Surface Electrocardiograms
This work is focused on different aspects within the loop of multiscale modeling:
On the cellular level, effects of adrenergic regulation and the Long-QT syndrome have been investigated.
On the organ level, a model for the excitation conduction system was developed and the role of electrophysiological heterogeneities was analyzed.
On the torso level a dynamic model of a deforming heart was created and the effects of tissue conductivities on the solution of the forward problem were evaluated
Nonlinear physics of electrical wave propagation in the heart: a review
The beating of the heart is a synchronized contraction of muscle cells
(myocytes) that are triggered by a periodic sequence of electrical waves (action
potentials) originating in the sino-atrial node and propagating over the atria and
the ventricles. Cardiac arrhythmias like atrial and ventricular fibrillation (AF,VF)
or ventricular tachycardia (VT) are caused by disruptions and instabilities of these
electrical excitations, that lead to the emergence of rotating waves (VT) and turbulent
wave patterns (AF,VF). Numerous simulation and experimental studies during the
last 20 years have addressed these topics. In this review we focus on the nonlinear
dynamics of wave propagation in the heart with an emphasis on the theory of pulses,
spirals and scroll waves and their instabilities in excitable media and their application
to cardiac modeling. After an introduction into electrophysiological models for action
potential propagation, the modeling and analysis of spatiotemporal alternans, spiral
and scroll meandering, spiral breakup and scroll wave instabilities like negative line
tension and sproing are reviewed in depth and discussed with emphasis on their impact
in cardiac arrhythmias.Peer ReviewedPreprin
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