Multiscale Consequences of Spontaneous Calcium Release on Cardiac Delayed Afterdepolarizations
نویسندگان
چکیده
منابع مشابه
A mathematical model of spontaneous calcium release in cardiac myocytes.
In cardiac myocytes, calcium (Ca) can be released from the sarcoplasmic reticulum independently of Ca influx from voltage-dependent membrane channels. This efflux of Ca, referred to as spontaneous Ca release (SCR), is due to Ryanodine receptor fluctuations, which can induce spontaneous Ca sparks, which propagate to form Ca waves. This release of Ca can then induce delayed after-depolarizations ...
متن کاملMultiscale modeling of calcium cycling in cardiac ventricular myocyte: macroscopic consequences of microscopic dyadic function.
In cardiac ventricular myocytes, calcium (Ca) release occurs at distinct structures (dyads) along t-tubules, where L-type Ca channels (LCCs) appose sarcoplasmic reticulum (SR) Ca release channels (RyR2s). We developed a model of the cardiac ventricular myocyte that simulates local stochastic Ca release processes. At the local Ca release level, the model reproduces Ca spark properties. At the wh...
متن کاملCalcium-activated Cl(-) current contributes to delayed afterdepolarizations in single Purkinje and ventricular myocytes.
BACKGROUND The ionic mechanism underlying the transient inward current (I(ti)), the current responsible for delayed afterdepolarizations (DADs), appears to be different in ventricular myocytes and Purkinje fibers. In ventricular myocytes, I(ti) was ascribed to a Na(+)-Ca(2+) exchange current, whereas in Purkinje fibers, it was additionally ascribed to a Cl(-) current and a nonselective cation c...
متن کاملCorrection: The Timing Statistics of Spontaneous Calcium Release in Cardiac Myocytes
A variety of cardiac arrhythmias are initiated by a focal excitation that disrupts the regular beating of the heart. In some cases it is known that these excitations are due to calcium (Ca) release from the sarcoplasmic reticulum (SR) via propagating subcellular Ca waves. However, it is not understood what are the physiological factors that determine the timing of these excitations at both the ...
متن کاملDelayed afterdepolarizations generate both triggers and a vulnerable substrate promoting reentry in cardiac tissue.
BACKGROUND Delayed afterdepolarizations (DADs) have been well characterized as arrhythmia triggers, but their role in generating a tissue substrate vulnerable to reentry is not well understood. OBJECTIVE The purpose of this study was to test the hypothesis that random DADs can self-organize to generate both an arrhythmia trigger and a vulnerable substrate simultaneously in cardiac tissue as a...
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ژورنال
عنوان ژورنال: Biophysical Journal
سال: 2015
ISSN: 0006-3495
DOI: 10.1016/j.bpj.2014.11.1457