Quantcast

Pressure-volume loops and decreased venous compliance

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.
Status
Not open for further replies.

rsweeney

Senior Member
15+ Year Member
Joined
Jan 6, 2003
Messages
358
Reaction score
13

Members don't see this ad.
When analyzing the pressure-volume loop for decreased venous compliance, would afterload be increased or decreased? Here is where I am at mentally. Decreased venous compliance-->decreased pooling-->greater amount of blood that returns to the heart--> increased filling-->increased preload-->frank-starling mech. activated so contractility increases thus you have an inc. in stroke volume-->increased cardiac output--> higher areterial pressure thus increased afterload.

BUT: When you analyze the pressure-volume loop for decreased venous compliance the end diastolic volume is increased [as it should be] and end systolic volume is decreased [as it should be due to inc. cardiac output]---but according to my reasoning afterload should be increased due to inc. cardiac output.

I thought that on a pressure-volume loop diagram afterload-increases are represented by a shift to the RIGHT along the end-systolic volume-pressure (ESVP)curve. But the actual PV-loop diagram for decreased venous compliance has a shift to the LEFT down the ESVP curve. What's going on or what am I missing??

So an increase to the right or left along the ESVP curve won't necessarily tell you whether you have an increase or decrease in afterload? Is this true?
-Thank you for any help

-Richard
 

DrMom

Official Mom of SDN
Moderator Emeritus
15+ Year Member
Joined
Apr 24, 2002
Messages
43,318
Reaction score
26
duplicate. closing

open one is in dental forum
 
Status
Not open for further replies.
Top