Pharm 10-Heart Failure Flashcards
What are some definitions of heart failure?
- Inability to effectively return all the blood volume it receives to the critter’s circulation
- The heart’s inability to deliver adequate oxygen to the critter’s body to maintain normal function and homeostasis
- The heart is unable to effectively provide the critter’s tissues with necessary metabolites and remove metabolic wastes
What is the symptomatic definition of heart failure?
A mismatch between right and left heart volume outputs
Cachexia
weakness and wasting of the body due to severe chronic illness.
Right-Sided Failure vs Left-Sided
Left-sided: Cachexia, backs up in lungs develop cough, can’t deliver to the body
Right-sided: ascites, backs up in the body
Cardio-centric definition of heart failure
The heart’s impaired ability to adequately fill with and or eject blood; implies dual causation (systolic and diastolic dysfunction)
What does diastolic failure look like?
Thick heart walls
Decreased ventricular filling
Decreased cardiac output
Patients tend to be “older”
Analogy: clown car is fine but you can’t get much into it
What does systolic failure look like?
Thin heart walls
Decrease in contractility (weakened heart muscle can’t squeeze well)
Decreased ejection fraction (left side wall is thin and stretched out so trouble pumping); fills ok
Tend to be “younger”
Batista Procedure
Cut out part of the left ventricle going to renormalize geometry of the heart; great results at first but then very bad
What are the 5 main causes of heart failure?
- Ischemia
- Idiopathic
- Viral
- Immune Mediated
- HTN
What is the most common cause of heart failure?
ischemia; 70% type of HF in America
Ischemia contributes to which type of heart failure dysfunction?
both systolic and diastolic
Idiopathic
Unknown cause
About how common is familial causes in idiopathic heart failure?
1/3
Describe viral heart failure.
Viruses “errantly” take up residence in myocardial cells; moderate/severe cardiomyopathy, may or may not resolve might require valvular Sx due to new cardiac geometry
Describe immune-mediated heart failure.
Cardiac antibodies attack cardiomyocytes
Link to other immune-mediate diseases
AMIs expose novel cardiac antigens affecting long-term prognosis
What forces contribue to the chronic downhill heart failure slide?
- Nervous system
2. Renin-angiotensin-aldosterone system
Why does the heart remodel?
Heart cells die and are replaced with fibrotic tissue and remaining cells hypertrophy
What are the goals of therapy for HF?
- Improve/alleviate critter’s symptoms
- Slow that downhill slide toward transplant/VAD/death
- Improve survival (increase QALYs)
6 Classes of QALY-Improving Drugs
- Positive inotropes
- Diuretics
- Renin/Angiotensin Blockers
- Primary Vasodilators
- B-Blockers
- Aldosterone Antagonists
- Neprilysin Inhibitor
What are the 3 types of positive inotropes?
- Cardiac Glycosides
- Catecholamines
- Bypyridines
What is an example of a cardiac glycoside?
Digitalis (Digoxin)
Describe the effects of Digitalis (Digoxin).
Positive Inotrope
Negative Chronotrope
Increased Baroreceptor sensitivity
Describe the therapeutic window of Digitalis (Digoxin)
Narrow therapeutic window (arrythmias, GI symptoms)
no evidence these drugs prolong life
How does Digitalis (Digoxin) work?
Blocks Na+/K+ -ATPase “The Sodium Pump”
What are catecholamines?
Classic B-1 adrenergic receptor stimulants
Powerful positive inotropes/chronotropes
What are some examples of catecholamines?
Epinephrine (Adrenaline)
norephinephrine (noradrenaline)
Dopamine
Dobutamine
What is the preferred drug for cardiac arrest?
Epinephrine (Adrenaline)
What are the functions of epinephrine (adrenaline)?
Preferred drug for cardiac arrest Anaphylactic reactions (predictable side effects)