heart failure

Question 1

cardiac output

Answer 1

stroke volume x hr

Question 2

preload

Answer 2

force that stretches cardiac muscle prior to contraction - volume filling heart from venous return

Question 3

afterload

Answer 3

pressure heart must exert to eject blood during ventricular contraction

Question 4

how to reduce preload

Answer 4

furosemide diuretics

Question 5

how to reduce afterload

Answer 5

increase diameter and increase contractility

Question 6

vasodilators used in heart failure

Answer 6

ACEi, ARBs, nitrates, PDEIs (afterload)

Question 7

diuretics in heart failure

Answer 7

furosemide (preload)

Question 8

positive inotropes in heart failure

Answer 8

B agonists, PDEIs, digoxin

Question 9

cardio-inhibitors in heart failure

Answer 9

b-blockers

Question 10

ACEi MOA

Answer 10

• Prevents angiotensin i → angiotensin ii

- Increase in peripheral vascular resistance = increased afterload

Question 11

side effects ACEi

Answer 11

dry cough and angioedema, hypotension, hypekalaemia

Question 12

diuretics in HF

Answer 12

Loop diuretics act on aLOH to block NaKCC channels → increased sodium excretion and decreased ECF volume

Question 13

side effects loop diuretics

Answer 13

hypokalaemia, deafness, renal toxicity

Question 14

mineralocorticoid receptor antagonists in HF

Answer 14

Act in DCT to block aldosterone receptors - limited expression of sodium and potassium channels -> reduced preload

Question 15

side effects mineralocorticoid antagonists

Answer 15

hyperkalameia and gynaecomastia

Question 16

b agonists in HF

Answer 16

e. g. dobutamine

- B1 is cardiac specific and increases force of contraction

Question 17

what would a1 do to heart

Answer 17

increase after load

Question 18

side effects b agonists

Answer 18

tachycardia and no benefit in chronic disease

Question 19

PDEIs in HF

Answer 19

• B1 adrenoreceptor

- Increase 2nd messengers intracellularly by preventing breakdown

Question 20

side effects PDEIs

Answer 20

hypotension, tachycardia and arrythmias

Question 21

what leads to increase heart contractility

Answer 21

b1 action

Question 22

what leads to increased vasodilatation

Answer 22

b2 action

Question 23

cardiac glycosides in HF MOA

Answer 23

• Ion exchange in myocytes
• Na/K pump inhibited
• Secondary inhibition of calcium/sodium exchange
• Rise in intracellular calcium = increased ionotropicity
• Lows AV conduction - used in AF

Question 24

cardiac glycoside e.g.

Answer 24

digoxin

Question 25

side effects cardiac glycosides

Answer 25

arruthmias, contraindicated in hypokalaemia/renal impairment

Question 26

B-blocker MOA in chronic HF

Answer 26

• Sympathetic nervous system
• Activation of sympathetic nerves during HF can cause arterioconstriction, venoconstriction, tachycardia and renin release
• That is why we block with B blockers

Question 27

side effects b blockers

Answer 27

bronchospasm in asthmatics, cold hands and feet

Question 28

treatment for HF

Answer 28

Loop diuretics (all patients) +/- oxygen (94-98%) +/- vasodilators (nitrates, don’t give if pt hypotensive)

Question 29

how to treat pt with HF in respiratory failure

Answer 29

CPAP

Question 30

how to treat hypotensive HF pt

Answer 30

If pt in hypotension (+ve inotropic agents) +/- vasopressor agents

Question 31

ongoing treatment for HF

Answer 31

ACEi and B blockers

Question 32

what to give if pt low tolerance to ACEi

Answer 32

ARBs