21-31 - Heart Failure Flashcards
bowditch phenomenon
icnreases in heart rate cause an increase in contractility ( saves CO - filling time issues)
frank-starling mechanism
increases in preload increase the contractility
Anrep =
if you increase the afterload, contractility will increase
in the excited state ____- preload is needed to increase SV because of changes in contractility
smaller preload to get same increase in SV
main cause CHF
cardiac remodeling
high risk for developing HF
stage A
- HTN
- CAD
- DM
- family hx
asymptomatic HF
stage B
- previous MI
- LV systolic dysfunction
- asymptomatic valvular disease
symptomatic HF
stage C
- known structural heart disease
- SOB and fatigue
- reduced exercise tolerance
refractory end-stage HF
stage D
- marked symptoms at rest despite maximal medical therapy
drug at all stages of HF
ACEi or ARB
drug starting at stage B of HF
b- blocker
added to ACEi or ARB
drug starting at stage C of HF
lots, notably Diuretics and Digoxin added to ACEi or ARB
symptomatic HF, african-american race
hydralazine and nitrates and ACEi and B blocker
symptomatic HF with afib
digoxin
ACEi
b-blocker
drug that is bridge to transplantation or end of life
positive ionotropes
4 practical approaches to increase intrinsic myocardial contractility
- increase cytosolic Ca2+
- increase myocardial cAMP
- agonism of B1 receptors
- increase B1 receptor density
what drugs increase B1 receptor density?
b1 adrenergic antagonists
example b adrenergic agonists
dobutamin, epinepthrin, NE, dopamine
what drugs increase myocardial cAMP
phosphodiesterase inhibitors
amrinone, milrinone
what drugs increase cytosolic Ca2+
cardiac glycosides
digoxin
MOA digoxin
blocks Na/K ATPase to increase intracellular sodium and extracellular Ca2+
positive ionotropic effects of digoxin
decrease EDV and ESV
decrease systemic and pulmonary venous pressure
decrease SANS
digoxin has a ____ vagal effect
direct –> increases vagal tone
how does digoxin affect coronary flow
increases it (by decrease hypertrophy)
adverse effect of digoxin
proarrhythmic
need to watch K levels
pharmacokinetics of digoxin
7 days to reach steady state
excreted by kidney
what inactivates digoxin
eubacterium lentum
and cimetidine
early sign of difitalis intoxication
anorexia, nausea, vomiting, visual change
you will see arrhythmia later
monitor K values!
does digoxin improve mortality?
no
I gave the pt too much digoxin - help!
cholestyaramin or digoxin immune Fab
MOA phsophodiesterase 3 inhibitors
block type III phosphodiesterase activity leading to an incrrease in caMP and –> vasodiltation, positive ionotropic and lusitropic effects
phosphodiesterase 3 inhibitors work downstream of what drug
b agonsits
what are the two phosphodiesterase 3 inhibitors?
inamrinone
milrinone
how do inamrinone and milrinone increase CO?
- directly stimualte myocardial contractility
- accelerate relaxation
- balance arterial and venous dialtion to decrease filling pressure
indication for inamrinone and milrinone
short term circulation support in advanced CHF
