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Cardiac Output and HTN
epoff20 posted:

I'm looking over my pharmacology book and it says, "The higher the CO the higher the BP". Can someone please explain this to me, I'm having trouble wrapping my head around it. If someone has high BP that would indicate that the vessels are having trouble pumping blood throughout the body increasing BP. A high CO would indicate to me that blood is easily being pumped through the body unless the body has fluid build up. I feel like it could be low BP or high BP if you have a high CO?

Thanks in advance for the responses,
Eric Poff
ABSN student
Jefferson College of Health Sciences
billh99 responded:
No medical professional normally responds in this forum.

You might find a forum for nursing or medical students.

However, let me try to answer this from an engineering background.

By CO I assume that you mean Cardiac Output. Or in engineering we would talk about the GPM (gallons per minute) flow from a pump.

The Blood vessels are somewhat elastic and can expand somewhat under pressure. Also hormones and medicines can cause the vessels to relax or contract.

How I don't know the context of that short sentence.

But if you take a person that starts exercising then the blood flow (CO) will increase to supply the needs of the muscles. While the vessels will enlarge somewhat to handle the extra flow. But it will not increase enough and the blood pressure will go up.

HR increase (and thus CO increase) along with increased BP is the normal response to exercise.

However, if you compare a single person at age 20 and then at age 60 you might find that the blood vessel and stiffened and/or plaque and thus the BP will be higher at the same CO.

Likewise you can give a person with high BP an ACEinhibitor which causes the vessels to relax and the BP will go down with the same CO.

Or you can give then a Beta Blocker which decreases HR and thus CO and the reduced blood flow will reduce BP.

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