Maybe lecture 30

Question 1

Heart failure is…
results in…
eventually becomes

Answer 1

despite adequate venous return, CO is insufficient to meet tissue demands

• compensation-sympathetic drive inc, inc HR, and vasoconstriction
• decompensation(undesirable effects)

Question 2

in early compensated heart failure inc vasoconstriction of peripheral veins/venules/arterioles leads to

Answer 2

inc venous return/EDV which leads to inc contractility
inc TPR/afterload
and inc cardiac work

Question 3

RAAS activation in early compensated heart failure leads to

Answer 3

further vasoconstriction
inc preload (blood volume-> venous return) and afterload (arteriolar resistance/BP)

Question 4

inotropes do what

Answer 4

inc the amount of Ca in the cell through cell membrane of SR

Question 5

What do beta receptors do(2)

Answer 5

change the sensitivity of the Ca channel

activate adenyl cyclase->inc cAMP, opening of RO Ca channels

Question 6

Cardiac effects from sympathetic stimulation in early compensated heart failure

Answer 6

inc HR, Inc SV->inc CO->inc work on a failing heart

Question 7

Sympathetic stimulation and Frank Starling principle in early compensated heart failure

Answer 7

Inc EDV->inc CO
but limited capacity to dilate
-start to get bad amount of preload

Question 8

Chronic activation of the sympathetic nervous system leads to(2)

Answer 8

reduced baroreceptor sensitivity(maintained sympathetic drive even when MAP is appropriate)
Down regulation of Beta receptors in the heart(dec capacity of heart to respond to sympathetic stimulation

Question 9

Chronic activation of RAAS(3)

Answer 9

persistent vasoconstriction->inc preload and afterload
Inc blood volume->inc preload
inc angiotensin->dec baroreceptor sensitivity

Question 10

contractility

Answer 10

the amount of tension that can be developed at any given stretch of the cardiac muscle

Question 11

What determines cardiac contractility

Answer 11

Ca levels inside the cardiac myocyte

Question 12

intracellular Ca levels alter when(2)

Answer 12

Ca enters through the cell membrane

Ca is released from SR

Question 13

Physiological modifiers of contractility: SNS
Transmitter?
Receptors?
transduction pathway?

Answer 13

NA
Beta 1 adrenoreceptors
activation of adenyl cyclase->inc cAMP->opening of RO Ca channels

Question 14

Positive inotropes

what 4 drugs are there

Answer 14

inc cardiac contractility by inc intracellular Ca levels
could be problematic because->inc workload on heart
pimobendan (calcium sensitizers)
PDE inhibitors
Beta agonists
Cardiac glycosides(digoxin)

Question 15

Negative inotropes

Which two drugs are there

Answer 15

reduce contractility
reduce preload
->reduce workload on heart
Beta blockers
Ca channel blockers