Pharmacology CHF - Beta Blockers, (+) inotropes, ARNI Flashcards
how are beta blockers helpful in CHF?
(2 points)
they reduce the sympathetic tachycardia reflex (this wastes oxygen)
reduce the preload on the heart
true or false
while loop diuretics do not improve the mortality rate for CHF patients, beta blockers DO
TRUE
4 negative heart effects from too much sympathetic activation as a compensatory mechanism for CHF
what class of drugs helps to block this sympathetic activation?
cardiomyocyte damage/death
arrythmia
interstitial fibrosis
beta adrenergic system desensitized
beta blockers help to prevent all these things from happening by blocking excess sympathetic stimulation
**2 advantages of carvedilol in particular in treating CHF
-reduces lipid peroxidation (free radical-induced)
-prevents cardiac and vascular smooth muscle mitogenesis
PLUS it has alpha and beta receptor blocking activity
true or false
in treating CHF, a combined alpha and beta blocker is preferred
true - like carvedilol
*true or false
beta blockers reduce catecholamine-induced cardiomyocyte toxicity
TRUE
they do this by inhibiting prolonged sympathetic discharge that is done as a reflex
*true or false
beta blockers cannot prevent or delay myocardial contraction dysfunction
FALSE - they can
*true or false
beta blockers DECREASE cardiomyocyte apoptosis
TRUE
*is it possible for beta blockers to induce myocardial remodeling
YES
by decreasing oxidative stress on the heart
for which CHF patients are beta blockers NOT recommended
with severe or new onset CHF
beta blockers are recommended for use in CHF patients along with…
ACE inhibitors or ARBS
**name 4 positive inotropes for CHF
digoxin
milrinone
dopamine
dobutamine
which + inotrope for CHF is a cardiac glycoside
digoxin
which + inotrope for CHF is a Phosphodiesterase inhibitor
milrinone
which + inotrope for CHF is adrenergic/dopaminergic cardiac stimulant
dopamine and dobutamine
differentiate between inotropes and chronotropes
what is lusitropy?
inotropes increase the force of contraction
chronotropes increase the RATE of the heart
lusitropy increases ventricular relaxation and filling
digoxin can be used to treat ___ and ____ by different mechanisms
CHF and A fib
CHF - increases calcium availability
a fib - blocks AV node conduction to help arrhythmias
explain how dopamine and dobutamine work
they interact with the B1 receptor of the heart to activate adenylyl cyclase and cause cAMP formation – which causes protein kinase activation
this in turn increases the membrane transport of calcium, which increases myocardial force of contraction – POSITIVE INOTROPES
name 2 + inotropes that increase the contraction of the heart through binding the B1 receptor
dopamine and dobutamine
***name 3 positive inotropes that are phosphodiesterase-3 inhibitors
explain their mechanism
xanthines
amrinone
milrinone
inhibit the breakdown of cAMP – which causes increase in protein kinase and increase in calcium – causing contraction
**is digoxin an inotrope?
how does it work?
yes
increases calcium available for contraction. inhibits the sodium/potassium ATPase – this causes intracellular sodium to increase - which leads to calcium intracellular accumulation as well via the sodium/calcium exchange system
positive inotropes are used mainly for systolic or diastolic dysfunction
systolic – NEED CONTRACTION
true or false
digoxin can be used in afib to correct arrythmias
true
blocks AV node condution
some ADR digoxin
arrythmias
hallucination
blurred vision
