Hemodynamics of Heart Failure

Question 1

when heart failure leads to a decrease in the contractility of the heart…what must make up for that to maintain an even SV?

Answer 1

there must be a higher preload

Question 2

a largely increased preload leads to what in HF?

Answer 2

pulmonary edema…in the lungs from LV to LA pressure increases

Question 3

what two types of heart failure really have decreased contractility?

Answer 3

dilated HF and ischemic HF

Question 4

due to low system pressure the baroreceptors are activated and lead to what change?

Answer 4

increase in sympathetic tone

Question 5

the increase in sympathetic tone has what effects on the heart and vessels?

Answer 5

increases HR and contractility of the heart

constricts the vessels..increase venous return

Question 6

the increase in sympathetic tone has what effect on the kidneys?

Answer 6

the NE tells them to release more renin and kick off the RAAS pathway

Question 7

with HF…the sympathetic is stimulated chronically in the heart…can cause toxic changes…list 6 of them

Answer 7

downregulation of B1 receptors
unfavorable changes in B1 signaling
energy starvation
cardiomyocyte death
Vent arrhythmias
fibrosis

Question 8

with the RAAS systme activated, why is it not turned off in HF? and what does this lead to?

Answer 8

the heart is not able to pump and perfuse the juxtaglomelular cells and these then signal for more renin release and more fluid uptake…so you get high fluid levels…edema

Question 9

what is the role of ANP and BNP in heart failure?

Answer 9

they help combat the RAAS and sympathetic NS symptoms from HF, but they are always chewed up quickly and cannot overcome the issue

Question 10

what does a positive ANP or BNP test tell you about the heart?

Answer 10

the myocytes are under some form of stress

Question 11

what two things cause increase in afterload and can lead to HF?

Answer 11

aortic stenosis and hypertension

Question 12

when you have secondary remodeling of the heart tissue…what is the main player?

Answer 12

fibrosis

Question 13

does fibrosis cause systolic dysfunction or diastolic dysfunction of the heart?

Answer 13

BOTH

Question 14

explain how heart failure leads to increased afterload on the heart?

Answer 14

heart failure causes a lower SV and CO…so you get an increase in SVR to help push blood…this SVR leads to higher pressure in LV and leads to increased afterload and further decrease of the CO

Question 15

describe the two ways afterload can increase in HF

Answer 15

increase in SVR

increase in radius of ventricle from remodeling and dilatation

Question 16

what is the typical change of contractility, SV, preload, and afterload with HF?

Answer 16

contractility decrease
preload increase
SV decrease
afterload is variable

Question 17

what type of heart failure has preserved ejection fraction and how does this happen?

Answer 17

HCM…because with HCM you have diastolic dysfunction with filling, but the systolic function is still normal

Question 18

if HCM has a preserved ejection fraction…what causes the heart failure?

Answer 18

due to the low filling from the increased diastolic pressure and decreased volume of the ventricle