Cardiac Lecture 4

Question 1

Which medications are considered mixed vasodilators?

Answer 1

Sodium nitroprusside and nitroglycerine (NO donors)

Question 2

Dilation of the veins decreases ______

Answer 2

Psf and RVR

Question 3

Nitroglycerine relaxes _____ more than ______

Answer 3

the veins more than the arteries

Question 4

What medications are arterial-specific vasodilators?

Answer 4

Hydrazaline and ACEi

Question 5

Which medication is a mixed pressor?

Answer 5

Phenylephrine

Question 6

Describe the body’s compensatory mechanisms for a failing heart

Answer 6

1. Short term:
   Decreased CO → increased sympathetic activity → increased venous tone and HR → increased RAP and CO
2. Long term:
   Prolonged sympathetic activity → increased fluid retention → increased Psf and RAP → back to normal sympathetic activity

Question 7

_______ includes the pressures available to fill the heart

Answer 7

preload

Question 8

______ the force that the heart has to overcome to open the aortic valve and eject blood

Answer 8

afterload

Question 9

________ the change in SV when preload and afterload remain constant

Answer 9

contractility

Question 10

______the volume in the ventricle after filling is complete

Answer 10

EDV

Question 11

EDV is a function of _______

Answer 11

preload

Question 12

a normal ESV is _____

Answer 12

50 mL

Question 13

increased preload results in?

Answer 13

increased EDV and SV

Question 14

a normal afterload is ______

Answer 14

80 mmHg

Question 15

How is contractility represented on a pressure-volume loop?

Answer 15

the slope at the top left-hand corner of the pressure-volume loop

Question 16

as contractility increases, the line shifts to the ______ and shifts to the _____ when it decreases

Answer 16

left (steeper slope); right

Question 17

increased afterload results in?

Answer 17

• increased ESV and duration of phase II
• decreased duration of phase III and SV

Question 18

increased contractility results in?

Answer 18

• decreased ESV
• increased SV, CO, and BP

Question 19

“Everybody has ______ by the time they’re 50”

Answer 19

aortic valve stenosis - most common valve problem

Question 20

Describe the effects of aortic valve stenosis on a pressure-volume curve

Answer 20

high afterload → increased ESV → decreased SV and CO
- elevated HR to compensate for low CO
increased preload

Question 21

Why would someone with aortic valve stenosis have a normal MAP?

Answer 21

the pressure choke point is before the aorta, so the aortic pressure would be lower and could result in a normal MAP

Question 22

You would expect the pulse pressure on someone with aortic valve stenosis to be _______

Answer 22

Narrow

Question 23

Describe the effects of mitral valve stenosis on a pressure-volume curve

Answer 23

• issues with filling → increased Psf, atrial pressure, and blood volume
• decreased EDV → decreased SV → increased HR

Question 24

Eventually, mitral valve stenosis will result in ______

Answer 24

pulmonary edema

Question 25

Describe the effects of aortic regurgitation on a pressure-volume curve

Answer 25

retrograde blood movement when the valve is closed and pressure in the aorta > ventricle → phase IV not isovolumetric - increased EDV → increased SV - decreased afterload

Question 26

At which point during phase IV does blood flow backward into the ventricle at the greatest speed?

Answer 26

end of phase IV - reflects low pressure in the ventricle bc it's supposed to be empty; slows down as the ventricle fills up

Question 27

What would you expect in the BP of someone with aortic regurgitation?

Answer 27

Wide pulse pressure

Question 28

Describe the effects of mitral regurgitation on a pressure-volume curve

Answer 28

- both phase II and IV not isovolumetric - increased ESV and EDV → increased SV