PV Loops (Quiz 2) Flashcards
What does a PV loop graph represent?
pressure and volume changes of the left ventricle during 1 cardiac cycle (1 heart beat)
What does A represent?
Mitral valve closes
what does B represent?
Aortic valve opens
what does C represent?
aortic valve closes
what does D represent?
mitral valve opens
what does 1. represent?
isovolumetric contraction
what does 2. represent?
systolic/ventricular ejection
what does 3. represent?
isovolumetric relaxation
what does 4. represent?
ventricular filling
what does the x-axis measure?
volume (v)
what does the y-axis measure?
pressure (p)
In a normal PV loop, where does C and D sit on the X-axis?
at the end-systolic volume (ESV)
In a normal PV loop, where does A and B sit on the x-axis
at the end-diastolic volume (EDV)
what is represented by the difference between EDS and ESV
stroke volume
In a normal PV loop, where does B sit on the y-axis?
Diastolic Blood Pressure ~ 80 mmHg
In a normal PV loop, where does C sit on the y-axis
Systolic Blood Pressure ~ 120 mmHg
what happens to the PV loop during increased preload?
(big list)
-becomes wider
-A and B have a right shift and slight superior shift
-slight increase of diastolic BP
-increase EDV –> increase SV
-increase strength of contraction
-more blood leave LV
what happens to the PV loop during increased afterload?
-becomes tall and skinny
-C and D have a right shift
-B and C have a superior shift
-increase of Systolic and diastolic BP
-increase ESV –> decrease SV
-less blood leaves the left ventricle
What happens to the PV loop during increased contractility?
-widens and gets taller
-C and D have a left shift
-pressure remains the same, but 2. is taller
–> more blood leaves LV
-decrease ESV –> increase SV
