Lecture 11 Cardiac Failure + Inotropic Agents

Question 1

Congestive HF is characterized by insufficient ___ to supply the ___ needed

Answer 1

CO, O2

Question 2

Systoilic failure: reduced mechanical _____ and ___ from the heart is reduced. the heart is ____ or ____

Answer 2

contraction; ejection; thin, dilated

Question 3

diastolic failure: vessel _____ and loss of _____ reduces CO. the deficit is in ____

Answer 3

stiffening, compliance; filling

Question 4

equation for CO

Answer 4

HR * SV

Question 5

Preoload is based on high _____ ____ and increased venous ____. Higher preloads result in pulmonary ____. Reduction of preload is the goal of _____

Answer 5

blood volume, tone;

congestion, diuretics

Question 6

With heart failure, the starling curve is shifted (up or down) and to the (left or right)

Answer 6

down, right

Question 7

Afterload is based on ____ impedence and systemic ____ ____

Answer 7

aortic/arterial;

vascular resistance

Question 8

besides preload and after load, what are the 2 other factors affecting cardiac performance? what is the major determinant of CO?

Answer 8

HR, contractility;

HR

Question 9

Another name for LV end diastolic pressure is ____

Answer 9

pre-load

Question 10

what is the compensation of CHF? myocardial _____, which helps CO but can lead to impairment of ____ filling and ischemia. ____ (structural changes made to the heart) leads to eventual ____ and greater load to the remaining myocytes

Answer 10

hypertrophy, diastolic;

remodeling, apoptosis

Question 11

class of drugs that is first line treatment of HF

Answer 11

ACE inhibitors

Question 12

inotropic agents cause the starling curve to shift ____

Answer 12

upward (ie increased stroke volume for a particular filling pressure_

Question 13

diuretics cause the starling curve to shift mainly to the _____. they reduce ___ but generally not ____

Answer 13

left; preload; mortality

Question 14

The main pathway activated during HF is _____

Answer 14

sympathetic pathway (ie increased renin, increased vasoconstriction, increased remodeling)

Question 15

CHF treatment:
does manipulating hemodynamics improve mortality (ie improving pumping)?
what about inhibiting compensation?

Answer 15

no, yes

Question 16

Drug classes that improve mortality in HF? (2 main ones) Which diuretic improves?

Answer 16

ACE inhibitors/ARBs and beta blockers;

spironalactone

Question 17

3 classes of inotropic agents for CHF:

which is for acute, which is for chronic?

Answer 17

cardiac glycosides = chronic

PDE inhibitors and B-adrenergic agonists = acute

Question 18

Digoxin/glycosides directly inhibit _____. This causes an increase in intracellular ____. This increase indirectly inhibits _____, leading to an increase in intracellular ____.

Answer 18

Na/K ATPase, Na;

Na/Ca exchanger, Calcium;

Question 19

increased intracellular calcium is pumped into the Sarcoplasmic reticulum by _____. calcium is pumped out of the SR by ____, which is activated by _____. Thus, increased intracellular Ca causes increased _____

Answer 19

SERCA (Sarcoplasmic endoplasmic reticulum ATPase);
Ryanodine receptor, calcium;
contractility

in summary: digoxin causes more Ca pumped into the cell. more Ca in the cell causes more Ca to be released from the SR, increasing contractilty

Question 20

what plant is digitoxin from

Answer 20

foxglove

Question 21

in addition to increased contractility, digoxin also stimulates the ____ ____, causing a decrease in ____

Answer 21

vagus nerve;

HR

Question 22

2 indications for digoxin:

Answer 22

CHF, Atrial arrhythmias ie (A fib)

Question 23

for ____ heart failure, beta agonists may be used. for _____ HF, beta blockers are used

Answer 23

acute, chronic

Question 24

digitoxin vs digoxin:
____ is more lipophilic.
____ is more potent.
____ has faster onset and shorter duration of action.

Answer 24

digitoxin;
digoxin;
digoxin

Question 25

digitoxin vs digoxin:
___ has better oral absorption.
____ is extensively inactivated by hepatic enxymes.
____ is more rapdily excreted by the kidney and should not be used in patients with impaired renal function

Answer 25

digitoxin;
digitoxin;
digoxin

Question 26

powdered digitalis (USP) has a _____ onset of action and a ____ half life

Answer 26

slow, long

Question 27

digoxin has a ____ therapeutic window. 3 most important side effects to watch

Answer 27

hyperkalemia, arrhythmia, AV block

Question 28

Other side effects = ___ problems, blurry ____ vision, and CNS ____

Answer 28

GI, yellow, depression

Question 29

factors predisposing to toxicity: renal ___, hypo____ (causes increased digoxin binding)

Answer 29

faiure, kalemia

Question 30

3 drugs that inhibit P-glycoprotein and can cause toxicity with digoxin:

Answer 30

verapamil, amiodarone, quinidine,

Question 31

how do you treat digitalis toxicity?

Answer 31

digoxin immune Fab

Question 32

2 drugs used in heart failure that are phosphodiesterase 3 inhibitors:

Answer 32

milrinone, amrinone (inamrinone)

Question 33

PDE inhibitors cause a decrease in ____ breakdown and thus an increase in ____. this causes an increase in ____ and an increase in _____ dilation

Answer 33

cAMP, cAMP;

contractility, arteriolar (decreased afterload)

Question 34

PDE inhibitors ____ mortality in CHF patients

Answer 34

increase

Question 35

2 beta adrenergic drugs used in acute HF:

Answer 35

dopamine, dobutamine

Question 36

besides dopamine receptors, at low doses, dopamine binds ___ receptors. at higher doses, it binds ____ receptors

Answer 36

beta 1;

alpha

Question 37

dobutamine mainly binds ___ receptors but also __ and ___ receptors. it causes a predominantly a ____ Effect

Answer 37

beta 1, beta 2, alpha;

inotropic

Question 38

digoxin has a ___ group. digitoxin has a ____ group and thus is more ____

Answer 38

hydroxyl; hydrogen; lipophilic