Extracellular Discontinuities in Cardiac Muscle
نویسندگان
چکیده
منابع مشابه
Extracellular discontinuities in cardiac muscle: evidence for capillary effects on the action potential foot.
It has become of fundamental importance to understand variations in the shape of the upstroke of the action potential in order to identify structural loading effects. One component of this goal is a detailed experimental analysis of the time course of the foot of the cardiac action potential (Vm foot) during propagation in different directions in anisotropic cardiac muscle. To this end, we perf...
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In their recent paper, Roberts et aL (1979) report the following values of intracellular (i), extracellular (o), longitudinal (<f), and transverse (t) resistivity for canine ventricular muscle: r^ = 450 ohms-cm, rot = 750 ohm-cm, ru = 360 ohm-cm, and rit = 3800 ohm-cm. The ratio W r ^ is 1.67. In an earlier paper, Clerc (1976) reported the following resistivity ratios for trabecular bundles fro...
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When the propagation velocity of action potentials is modified by changing the internal resistance of a cell, cable theory predicts that the shape of the action potential upstroke should not change; changes in velocity associated with changes in the upstroke usually are attributed to changes in membrane properties. However, we observed, in normal cardiac muscle, that changes in the upstroke wit...
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Injection of a brief stimulus pulse resets the spontaneous periodic activity of a sinoatrial node cell: a stimulus delivered early in the cycle generally delays the time of occurrence of the next action potential, while the same stimulus delivered later causes an advance. We investigate resetting in two models, one with a slow upstroke velocity and the other with a fast upstroke velocity, repre...
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ژورنال
عنوان ژورنال: Circulation Research
سال: 1998
ISSN: 0009-7330,1524-4571
DOI: 10.1161/01.res.83.11.1144