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Old 04-25-2013
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Question Hyperkalemia n action potential

any body can please tell that How hyperkalemia converts fast response cell into slow response cell? How hyperkalemia cause shortening of QT interval?

What i hav understood so far is that

when there is hyperkalemia initailly it increases excitibility by making membrane potential less negative allowing Na channels to open sooner bt if hyperkalemia persists longer then fast channels of na are inactivated bcoz membrane potential is becoming more n more positive. as a result of Na channel inactivation action potential ll be diffficult to generate. thus fast response cell is converted into slow response cell bcoz of hyperkalemia

regarding second question i think dat initially hyperkalemia causes depolarization to prolong thus prolonging action potential bt as it persists longer causing again higher K concentration inside cell eventually leading to rapid potassium efflux not allowing Ca influx to maintain plateau, speeding up repolarization n shorting action potential.Thus hyperkalemia causes shortening of QT interval So this is all wat i hv conceived so plz do correct me if i m wrong
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Cardiovascular-, Electrolytes-, Physiology-

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