Heart Failure Flashcards
What class of drugs are 1st line treatment for patients with mild-mod-severe HF?
What is their general mechanism of action?
How do they affect HR and contractility?
ACE Inhibitors
Arteriovenous dilation –> decrease SVR + BP –> increase CO + exercise tolerance
*ACE-Is also induce diuresis/natriuresis
No effect on HR/contractility
What are 3 therapeutic advantages of ACE-inhibitors?
- Inhibit LV remodeling post-MI
- No neurohormonal activation or reflex tachycardia
- No tolerance issues
What are two situations when Angiotensin Receptor Blockers can be used?
There were 6 examples of ARBs, and they all have the end in -sartan. Name them.
(Clue: LIVCOT)
Indications:
1) Use in place of ACE-Inh when cough is an issue
2) Can be used in tandem with ACE-Inh
ARBs:
1) Losartan
2) Irbesartan
3) Valsartan
4) Candesartan
5) Olmesartan
6) Telmisartan
What is the mechanism of action for ARBs?
How do ARBs affect the following?
- -Bradykinin
- -cardiac/vascular remodeling (promote or inhibit?)
- -renal excretion of Na & H2O (promote or inhibit?)
Mechanism
Block AT1-Rs on vasc endo –> inhibit vasc sm mm contraction
ARB Effects
- -No effect on bradykinin (so no cough)
- -Inhibit CV remodeling
- -Promote renal excretion of Na + H2O
Characterize how the following are altered as side effects of ARBs.
- -blood pressure
- -potassium levels
- -GFR
What side effect is missing, compared to ACE-Is?
ARB Side Effects
- -hypotension
- -hyperkalemia
- -decreased GFR
- -angioedema
There is no cough.
In the setting of HF, how do diuretics affect the following factors?
- -volume & preload
- -CO
- -arterial distensibility
- -neurohormal activation
Diuretics in HF:
–decreased volume & preload
–no direct effect on CO, but preload reduction can decrease CO
–improved arterial distensibility
–increased levels of noradrenaline, Ang2
In the setting of HF, what are two side effects and one contraindication to the use of diuretics?
Side Effects
1) volume contraction
2) electrolyte depletion
Contraindication
1) hypovolemia
What are two aldosterone antagonists that are used in treatment of HF?
In what type of HF are they used?
What are their side effects as related to electrolyte levels, sex hormones, and GI?
Spironolactone, Eplerenone
Used in more serious types of HF (eg, Class3-4 symptoms), sometimes in combo with ACE-Is
Side Effects
–hyperkalemia, metabolic acidosis, gynecomastia, GI disturbances (eg peptic ulcer)
What are the 3 Beta Blockers that are used in HF to inhibit the adverse effects of the sympathetic nervous system?
Bisoprolol, Carvedilol, Metoprolol
What is the name of the cardiac glycoside used to treat HF?
Describe the mechanism of action related to:
1) increasing contractility
2) reducing AV node conduction velocity
Digoxin
Mechanism of Action
1) inhibit Na/K ATPase –> increase [Na]i –> alter activity of NCX –> increase [Ca]i –> increased contractility
2) increase vagal efferent activity to heart –> reduce AV node conduction velocity
How does Digoxin affect the following hemodynamic parameters?
CO, LVEF, exercise tolerance, natriuresis, and LVEDP?
Increased
–CO, LVEF, exercise tolerance, natriuresis
Decreased
–LVEDP
How does Digoxin affect the following neurohormonal parameters?
NE levels peripheral nervous system activity RAAS activity Vagal tone Arterial baroreceptors
Decreased
- -plasma NE levels
- -peripheral NS activity
- -RAAS activity
Increased
–vagal tone
Normalizes arterial baroreceptors
What are some toxic effects associated with Digoxin?
Cardiac arrhythmias (atrial tachycardia, AV block)
How does Dobutamine increased contractility and HR?
In what situation is it used?
Dobutamine = B1-R agonist –> increase contractility & HR
Acutely decompensated HF
What are the side effects of Dobutamine…
at low doses?
at high doses?
Dobutamine Side Effects
@ low dose
–stimulate B2-Rs –> vasodilation
@ high dose
–stimulate alpha-Rs –> vasoconstriction
