Heart failure

Question 1

Causes of volume overload

Answer 1

L - R shunt
Valvular regurgitation
CHD
AV malformation 0 vein of Galen/hemangioma

Question 2

Cardiac arrythmias

Answer 2

congenital compelte block
SVT
VT

Question 3

Pressure Overload

Answer 3

L heart obstruction
- coarctation
- aortic stenosis
- hypoplastic left heart
Acute HTN: HUS, glomerulonephritis
R heart obstruction: pulm stenosis

Question 4

Causes of ventricular dysfunction

Answer 4

Myocarditis
cardiomyopathy - dilated/hypertrophic/restrictive
sepsis
anaemia
pericardial effusion/tamponade
ischaemia

Question 5

how does angiotensin 2 compensate in HF

Answer 5

• potent vasoconstrictor to incerase BP
• stim NA release from SNS
• promotes release of aldosterone

Question 6

how does aldosterone 2compensate in HF

Answer 6

• increases Na ans H20 resorption and K secretion
• increases circ blood vol - increases centreal venous p (preload)
  however causes peripheral oedema

Question 7

how does ADH compensate in HF

Answer 7

Increase H20 absorption and decreases UO to increase total blood vol (preload and afterload)

Question 8

how does endothelin compensate in HF

Answer 8

potent vasoconstrictor from vascular endothelial cells
promotes Na retention
endothelin 1 can be used as a prognostic factor for HF

Question 9

function of diuretics

Answer 9

furosemide, spironalactone
increase excreition of Na and H20
decrease vol in circulation (preload)

Question 10

function of ACEi

Answer 10

prevent conversion of Ag1 to Ag2, this increases plasma renin levels and decreases aldosterone

acts as systemic vasodilator decreases systemic vascular resistance , this decreases afterload

Question 11

function of aldosterone antagonist - spironalactone

Answer 11

competes with aldosterone receptor sites in distal renal tubule

H20 excretion whilst retaining Na and K

Question 12

function of beta blockers

Answer 12

increase stroke volue
decrease contractility and ventricular size

Question 13

function of phosphodiesterase 3 inhibitor e.g. milrinone

Answer 13

positive inotrope
vasodilator without chronotropic effect (NO increases HR)

Question 14

function of cardiac glycoside - digoxin

Answer 14

inhibits Na/K ATPase - increase intracellular Na and Ca

this increases force of contraction and decrease firing of AP

Question 15

function of catecholamines - dopamine

Answer 15

stimulate b1, a1 and dopaminergic R
affects vasodilation, increases HR and contractiliy and can icnrease systemic vascular resistance

Question 16

function of dobutamine - sympathomimetic

Answer 16

stronger B action than alpha
increase contractility and systemic vasodilation

Question 17

function of alpha agonist - adrenaline

Answer 17

increases peripheral vascular resistance - alpha
positive chronotrope and inotrope - B2

Question 18

Factors decreasing HR

Answer 18

PNS stimulation
digoxin
increase potassium
hypoxia
Na and Ca channel blockers
hypohtermia
Beta blockers
muscarinic receptopr agonist

Question 19

Factors increasing HR

Answer 19

SNS stimulation
muscarinic antagonist
beta adrenoceptor agonist
circulating catecholamines
hyperhtyroidism
hyperthermia
decreases potassium