Positive Inotropes

Question 1

Cardiogenic shock causes

Answer 1

MI
Myocarditis
Arrhythmias
Valvular disease
CMP

Question 2

Obstructive shock

Answer 2

Tamponade
Tension pneumo
PE

Question 3

Distributive shock

Answer 3

Sepsis
Anaphylaxis

Question 4

What does CHF respond to?

Answer 4

preload reduction
afterload reduction
Improved contraction

Question 5

Low cardiac output syndrome (LCOS) causes

Answer 5

in patients coming off CPB
A combo of:
Inadequate DO2
Hemoilution
Hypocalcemia, hypomagnesemia
Kaliuresis
Tissue thermal gradients
Variable SVR

Question 6

LCOS risk factors

Answer 6

DM
Old age
Female
Pre op decreased EF
Long duration CPB

Question 7

LCOS patho & treatment

Answer 7

Stunned hypocontractile myocardium in response to ischemia and reperfusion
Positive inotropes
Increase DO2 (SvO2 >70%)
Increase VO2 (arterial lactate <2mmol/L)

Question 8

cAMP dependent vs independent drugs

Answer 8

Beta agonists, dopaminergic agonists, PDE inhibitors
Cardiac glycosides
Calcium

Question 9

Inodilator drugs and effects

Answer 9

Isoproterinol
Dobutamine
–
Increase HR
Increased AV conduction
Decreased SVR/PVR
Variable myocardial o2 consumption

Question 10

Inoconstrictor drugs and effects

Answer 10

NE, Epi, Dopamine
Increased SVR
Increased O2 consumption
Increased HR

Question 11

When not to use inodilators?

Answer 11

Tachyarrhythmias

Question 12

When not to use levo/NE?

Answer 12

Low CO
this will decrease perfusion and cause renal failure

Question 13

When not to use Dig?

Answer 13

Hypokalemia, renal failure, bradycardia, drug interactions

Question 14

Arrhythmogenic potenital

Answer 14

1- isoproterinol
Epi
DA
Dobutamine

Question 15

How does cAMP work in the heart

Answer 15

Drug bind Gs receptor on cell membrane
Gs actives adenylyl cyclase
Adenylyl cyclase converts ATP to cAMP
cAMP cause contraction via influx of CA from slow channels and causes ca sensitivity of CA regulatory proteins
cAMP broken down by PDDE3 to AMP

Question 16

EPI receptors per dose

Answer 16

low- B2 1-2mcg/min vasodilation decreases SVR, though map stays same from mild increase in CO
Medium- B1 4mcg/min increase HR , inotropy, automaticity (PVCs)
high- A1 >4mcg/min

Question 17

Catecholamine complications

Answer 17

Tissue ischemia
increased myocardial consumption and work
Inrease cardiac arrhythmias
Enhance lipolysis and gluconeogenesis
Activate coagulation

Question 18

Isoproterinol effects

Answer 18

B1 B2
Increase hr, inotropy
Decrease SVR and DBP
Increased CO and decreased map
Bronchodilator

Question 19

Isoproterinol SE

Answer 19

Tachycardia
DBP hypotension
Increased O2 consumption
Arrhythmias
Dont use in pt with ischemic heart diseases

Question 20

Indications for isoproterinol

Answer 20

3rd degree HB
Bronchospasm during anesthesia
Decrease PVR in PH
Torsades, short QT syndrome

Question 21

Dobutamine

Answer 21

B1 B2 small A1
Not as strong as isoproterinol
No DA
Increases renal blood flow by increasing CO
Increases CO and HR
High doses may cause arrhythmias
Not useful in low SVR/low BP patients

Question 22

How must dobutamine be prepared?

Answer 22

D5W not NS which will inactivate it

Question 23

DA and glucose, oxygen

Answer 23

inhibits release of insulin, causing hyperglycemia
Blunts respiratory drive

Question 24

PDE3 inhibitors effects

Answer 24

Stop the breakdown for cAMP
Increase CA influx
Increase sensitivity of contractile proteins to CA
Increased CO, although decreased SVR and PVR

Question 26

PDE3 inhibitor drugs

Answer 26

Milrinone- no risk of thrombocytopenia, stronger than inamrinone, shorter half life, decreased dose in RF.
Inamrinone- increases SC and CI after CABG, more effective than DA, but equal to epi causes thrombocytopenia,

Question 27

Glucagon effects

Answer 27

Increases CI, HR, BP, decreases SVR and LVEDP

Question 28

When to use glucagon, SE

Answer 28

Cardiac failure caused by beta blockers
NV, hyperglycemia, increased PVR/ coronary perfusion

Question 29

Dig class and effect

Answer 29

Cardiac glycoside
Positive inotrope
- chronotropy
- dromotropy

Question 30

Dig MOA electrolytes

Answer 30

Block (slows) NAKATPase, which holds NA in and keeps K out
This reduced NA doesnt allow NA/C pump to work, keeping more CA inside cell

Question 31

When to use dig

Answer 31

A fib RVR
HF
Often used with diuretic and ace inhibitor

Question 32

Dig toxicity effects

Answer 32

> 3ng/ml
Hyperkalemia bc it cant go back into cell
Risk factors: hypokalemia, hypomagnesemia, hypoxemia, hypercalcemia, hypothyroid

Question 33

DIG toxicity presentation

Answer 33

Anorexia, nv
PVC
Atrial tachy w block
V fib and death
2nd degree type 2 block

Question 34

Dig toxicity treatment

Answer 34

K, Mag, O2
Phenytoin/lidocaine for arrhythmias
Atropine for low hr
BB for automaticity
pacing if HB

Question 35

Digibind

Answer 35

binds to dig in dig toxicity
eliminated by kidneys
levels are useless for several days so dont check

Question 36

Dig interactions

Answer 36

Amio
Verapamil
PPI
Reglan
many more

Question 37

Giapreza effects / se

Answer 37

Vasoconstriction and aldosterone release
interaction with acei and arbs
se: DVT so give prophylaxis blood thinner
tachycardia, delirium, thrombocytopenia

Question 38

Plan for low CO

Answer 38

Real 1st- optimize HR
1st- optimize preload
2nd- optimize afterload
3rd- optimize inotropy
Last- IABP, LVAD if low CO and ischemia persists

Question 39

Dig normal sign

Answer 39

Swoop in QRS

Question 40

Dig normal sign

Answer 40

Swoop after QRS

Question 41

Renal dose Dopamine

Answer 41

0.5-2mcg/kg/min
Increased RBF, GFR, NA secretion, urine out put, but NOT RENAL PROTECTIVE

Question 42

Levo doses

Answer 42

CO increases at low doses, but high doses increase afterload and cause reflex brady