Cardiac Pressure Volume Loops

Question 1

Resting volume in left ventricle

Answer 1

Minimum volume of blood in ventricle needed to prevent the heart from collapsing

Question 2

Point A

Answer 2

Blood flows in ventricles > expansion and no increase in pressure
Atrial boost

Question 3

Point A

Answer 3

Filling > ventricles at max capacity = EDV

Question 4

Point B

Answer 4

At point B = isovolumetric contraction begins where mitral valve closes hence contraction of vesicles increases pressure
Vol constant

Question 5

Point C

Answer 5

Aortic valve opens once ventricular pressure»>aortic pressure
Ejection takes place
Volume decreases
Pressure rises then falls until below aortic pressure

Question 6

Point D

Answer 6

Backflow causes closing of aortic valve
ESV
Width of the loop represents stroke volume
After contraction isovolumetric relaxation occurs rapidly decreasing the pressure of the ventricles, volume remains constant

Question 7

Area of pressure volume loop

Answer 7

Ventricular work per beat

Question 8

Diagnostic loop

Answer 8

Narrow width = decreased stroke volume

Taller curve = stronger force of contraction