hey guys I have a pretty basic question about cardiac output and its relation to mean arterial pressure that I can't seem to figure out. When afterload goes down this makes cardiac output go up but I saw that this also makes MAP go down. Why is that? The equation MAP=COxTPR makes it seem as if they should be proportional to each other. Thanks!
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Step I Cardiac Output and MAP
Started by cwaranch
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Because the biggest affect on afterload is likely to be TPR. If TPR goes down in such a way that it decreases MAP, then CO will increase to compensate and try to keep MAP constant. This is what happens with drugs like hydralazine that cause reflex tachycardia; the heart increases sympathetic stimulation in order to try and maintain blood pressure in response to the vast decrease in TPR.
I think it is always important with physiology to think of most equations as loose guides. The way these variables work in a biological system is more complex than a 3 number math equation.
I think it is always important with physiology to think of most equations as loose guides. The way these variables work in a biological system is more complex than a 3 number math equation.
