Goljan's definition of Systolic and Diastolic Pressure!

[EthanHunter]

Hi, Folks! I had some problem understand this concept in Goljan patho notes. He wrote that systolic pressure correlated with stroke Volume (SV), which i m kind of agree. Think he meant to say Systolic performance is depend on Preload (SV) and contractility. Hwever, when i read his definition for diastolic pressure correlates with states of contraction of total peripheral resistance. This concepts i dont understand at all. I thought TPR correlates more with systolic ie; Esstential HTN due to arteriosclerosis increase TPR leads to HTN. So if someone can explain this to me i would be appeciate very much. Thanks.

[IMG SURVIVOR]

Please have in mind Im at work :0)
1- Diatolic pressure the ventrices are filling up.
2- If the patient goes into tachycardia the blood will go faster back to the heart, the diastolic portion will be decrease.
3-remember that he says in HTA the heart pump the blood out, the patient has increase TPR, and the blood that the heart just pump out, came back and the heart will be like didnt I just pump you out right now?
This is goljan explanation.
Please anyone correct me, this is a really fast reply

my 2 cents

[EthanHunter]

i agreed with ur 1st twos statements, but if it's about increase TPR causing back flow to L Ventricle leading to increase Preload-increase SV, then would it be Systolic Pressure relationship not Diastolic? Sorry Maybe i am jz not getting it :).

[Dr. X]

Think he meant to say Systolic performance is depend on Preload (SV) and contractility
???? i dont get this one.

preload - end diastolic volume related to right atrial pressure.
sv - end diastolic volume - end systolic volume.

I think the question you're ultimately asking why is the increase in TPR effects the diastole and not systole?

In HTN, there is an increase in systolic and diastolic pressure (140/90)

systolic - highest arterial pressure
diastolic - lowest arterial pressure

when you vasoconstrict, there is an increase in TPR. This effects the diastolic pressure MORE than systolic pressure. .

Systolic is measured as stroke volume is coming out hence the correlation. Tonicity or compliance of the vessels doesnt matter as much during this process.
Diastolic is measured when heart is filling up as pressure is low in the arteries. Tonicity or compliance of the vessels matters here because it can significantly increase or decrease the arterial pressure.

Pearls you should take to exam:

increased systolic - increased sv makes it happen because there is an increase in plasma volume.
increased diastolic - increased tpr makes it happen because there is vasocontriction.

you know that in essential HTN both are caused by Na+ retention.

[Dr. X]

increase TPR causing back flow to L Ventricle leading to increase Preload-increase SV, then would it be Systolic Pressure relationship not Diastolic

Increase in tpr is not really the reason why there is an increase in sv.

in fact, increase in tpr (by vasoconstriction) causes a decrease in venous return. by frank starling relationship, this means there will be a decrease in cardiac output as well. thus, there will be decrease in sv.

In HTN systolic - increase in plasma volume overrides this and causes an increase in sv (increase in CO) leading to increase in systolic pressure.
In HTN diastolic - increase in TPR wins and causes an increase in diastolic pressure.

this is why you see increase in CO and TPR in Hypertension (pg. 243 FA)

so when you got HTN.. lay off the salt.. no more mcdonalds fries :(