Hypercalcemia and QT interval

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Hypercalcemia and QT interval

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6 Posts

shazbaz
Forum Junior

Topics: 15
Posts: 51

06/07/08 - 10:20 PM

Hey guys had a quick concept that i got stuck on. Kaplan notes say that hypercalcemia shortens the QT segment. And then they go on to say that QT segment corresponds to the plateau phase of the action potential. I was confused as to how this would happen. I was thinking that since in the plateau phase the calcium channels are open and calcium moves into the cell. So in hypercalcemia more calcium would move in hence prolonging the QT segment rather than shortening it. I looked at it from this angle but maybe there is a different way to look at it. Would appreciate the help. thanks.

shazbaz
Forum Junior

Topics: 15
Posts: 51

06/11/08 - 04:35 PM

Ok since nobody had any input ..this could be a logical explanation..maybe! I was thinking since calcium has a tendency to block sodium channels (as seen in hypocalcemic tetany) maybe hypercalcemia has an effect on sodium channels or inward movement of sodium during the plateau phase. I learned that sodium and calcium both move in during the pleateau phase so maybe because of hypercalcemia sodium entry is blocked and so replarization is quicker and hence shorter pleateau phase and so shorter QT segment. Is this a possible explanation maybe

arlete
Intern in 2009!!!!!
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Topics: 38
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06/11/08 - 05:23 PM

Just think like this: more calcium available, enter the cell faster, reach the quantity that is supposed to enter faster, shortens QT.

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custutor
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06/20/08 - 01:54 PM

more Ca will cause tachycardia so short QT interval

Jackofknives
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06/20/08 - 04:30 PM

I offically declare this question irrelavent

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doctor123
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06/21/08 - 01:26 AM

arlete

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