epinephrine blocking and whatnot

[lilmisty]

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So a practice q I just did pointed out that epinephrine + beta-blocker would give a rise in diastolic blood pressure.

This makes sense and all (epinephrine + beta-blocker = primarily a1 receptors stimulated), but I was confused as to they specified diastolic blood pressure...would you not see a rise in systolic blood pressure as well? Or would you see a rise in both, and I am just picking the question apart too much?

 

[Matteo]

my understanding (I think pathoma mentions it too) is that diastolic BP is more dependent on SVR (alpha-1 and beta-2 play a large role here), and systolic is largely based on SV (beta-1)- although I would assume both would increase, but by different extents. someone correct me if im glaringly wrong?

 

[Toy303]

So I didnt remember this until you mentioned the question but the Kaplan dude for cardiac
has a little schematic to help you understand how systole and diastole are dependent on CO and TPR given the equation MAP= CO/TPR i.e systole/diastole

both values while dependent on compliance ...diastole is also dependent on TPR (so its like a double whammy)


so all in all I agree with Matteo!

 

[tantacles]

my understanding (I think pathoma mentions it too) is that diastolic BP is more dependent on SVR (alpha-1 and beta-2 play a large role here), and systolic is largely based on SV (beta-1)- although I would assume both would increase, but by different extents. someone correct me if im glaringly wrong?

My understanding is that diastolic blood pressure would definitely increase because of A1 stimulation, but the carotid baroreceptors (reflexive) AND the B1 blocking (Since all of the beta blockers I know are either selective for B1 or nonselective) would cause decrease in HR and contractility, leading to a potentially decreased systolic BP and cardiac output.

 

[lilmisty]

Thanks everyone! Very well explained and friendly heheh