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The generation of the cardiac action potential: after the first millisecond

, : The generation of the cardiac action potential: after the first millisecond. Annals of Biomedical Engineering 11(3-4): 159-176

After an initial, transient voltage- and time-dependent burst of sodium current (equivalent to that occurring in nerve), the membrane current of cardiac muscle reverses in sign to a maximum value that is orders of magnitude smaller than that seen in nerve. The membrane of cardiac muscle, rather than exchanging an increased permeability to sodium ions (Na+) for one to potassium ions (K+), appears to become relatively impermeable to a variety of ions. It is argued that in a tissue such as cardiac muscle where the time when the cell is active is comparable to that when it is quiescent, the current generated by the active electrogenic transport/exchange of Na+, K+, and Ca2+ must be comparable to the corresponding currents generated by the passive transport of these ions. Consequently, the complex voltage and time dependency of the membrane current on the time scale of repolarization and beyond is generated, at least in part, by the complex time and voltage dependency of these transport/exchange processes. Measurement of the electrochemical properties of such transport/exchange mechanisms must ultimately be made on the individual mechanisms in isolation, e.g., in artificial membrane systems, before their contribution to the generation of the cardiac action potential can be unequivocably determined.


PMID: 6670782

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Schonfeld, W.H.; Eikin, E.P.; Woltering, E.A.; Modlin, I.M.; Anthony, L.; Villa, K.F.; Zagari, M., 1998: The cost-effectiveness of octreotide acetate in the treatment of carcinoid syndrome and VIPoma. Markov modeling was used to evaluate the cost-effectiveness of octreotide in treating carcinoid syndrome and VIPoma. For each condition, using octreotide was associated with doubled survival time. Octreotide was cost-effective for treating carcino...

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Letac, R.; Chassaigne, J.P.; Letac, S., 1963: Pathogenic And Therapeutic Aspects Of Bywaters' Syndrome. Marseille Chirurgical 15: 195-197

Podgor, M.J.; Remaley, N.A.; Chew, E., 1996: Associations between siblings for esotropia and exotropia. Objective: To quantify familial aggregation of esotropia and exotropia in children examined in a large multicenter study. Methods: Pregnant women and their children were examined in the Collaborative Perinatal Project of the National Institute of...

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