Lecture 6: HF Flashcards
pts diagnosed w HF have a ____________ _____________ mortality rate after their 1st hospital admission
50% 5-year
one in every 2 pts diagnosed will die at 5 yrs, this increases w each hospitalization, and profoundly after the 3rd
common misconceptions around HF
It is a chronic condition, can come on suddenly
Long term condition
Your heart does not stop beating - it just beats ineffectively
This is NOT normal for aging, comes from damage to the heart muscle
More exacerbations the more compromises the patient will have
what is HF
- characterized by inability of myocardium to pump enough blood to meet body needs
- abnormal clinical syndrome involving impaired cardiac pumping or filling, or both
- response to cardiac dysfunction
what is the most common cause of HF
Most common cause of heart failure: HTN (because heart is pumping against pressure, and if it can’t pump effectively it decreases C/O)
Maintain our hypertension
what can high cholesterol lead to
High cholesterol -> coronary artery disease -> heart attack and stroke
what can hypertrophy of the heart cause
Hypertrophy heart -> you wont have the same filling as you would if your heart could relax causing decreased C/O.
why is increased HR bad
Increased HR - decreasing filling time - don’t get perfusion from arteries to heart - so overall less effective
what is valvular disease
Valvular disease -> when valves don’t open and shut properly. If your valves aren’t shutting properly, we won’t have that closed system and will have leakage. If we have stenosis - this will be pushing against higher pressure, so takes more energy.
R sided HF
R sides HF - having trouble pulmonary system (PE, pulmonary HTN - will increase pressure in this system)
L sided HF
L side - having trouble pumping to systemic system
top 3 most common HF causes
- CAD -> MI
- hypertension
- valvular disease -> rheumatic disease
most common causes of HF overall (a lot)
- CAD, MI
- HTN
- valvular disease
- CHD
- pulm HTN (r sided), PE
- infiltrative disorders
- pericardial disease
- inflammatory (myocarditis)
- cardiomyopathy
- dysrhythmias
- meds non-compliance
review norm circulation
what are 3 major sys that are recruited when myocardial injury occurs
- SNS
- RAAS
- Natriuretic peptide sys
explain how the 3 major sys that are recruited when myocardial injury occurs (i am sorry this is so long fix this slide)
Myocardial dysfunction
- Decreased CO, systemic bp, and perfusion to kidneys
So this stim SNS sys - what can we do to increase output?
Can increase bp, and HR to help perfusion.
Vasoconstriction - increased BP and HR
Good ideas except, heart is not pumping enough out bc its failing, so makes it difficult to do its job. So this isn’t very helpful. Lessens our perfusion, increase stuff on the heart. Not great if someone has HF.
Our HF pts are on beta blockers bc it interferes w SNS.
Will also activate our RAAS sys -> causes vasoconstriction - increasing bp, stim release of aldosterone, also increase pressure, further cause vasoconstriction, increase pertrophy?, overtime these are not helpful not good longterm. -> so to stop our RAAS sys = we use ACE inhibitors + ARBs if they cant tolerate ACE.
Natriuretic peptide sys - in our atria and ventricles, increased stretch our heart releases these peptides, increased stretch = increased volume, which we know in HF we are not pumping out well, if RAAS sys is instigated and retaining fluid - this puts up our volume. Our pituitary gland - antidiuretic hormone - works on distal tubules to increase volume - and then we have stretch - our heart releases our naturetic peptides, and they do a few things. They interfere w RAAS sys, cause vasodilation, increase excretion of Na and H2o, we like this sys so we do things to keep making this system work.
how does SNS elevation try to compensate for HF
- increases HR and contractility
how does neural-hormonal response try to compensate for HF
- increase in Na and H2O retention (RAAS)
- posterior pituitary gland secretes ADH
- production of endothelin - potent vasoconstrictor
- proinflammatory cytokines are released by heart - causing hypertrophy, contractile dysfunction, and cell death
how does the frank starling mechanism try to compensate for HF
- dilation of ventricle
- increased pressures result in increased volume at end of diastole
- increased stretch initially adaptive - eventual overstretch results in ineffective contraction
how does ventricular hypertrophy try to compensate for HF
- increase in muscle mass and cardiac wall thickness in response to overwork and strain
- develops overtime, generally following persistent or chronic dilation
what do HF hearts look like + why is hypertrophy not great
HF can have big stretchy hearts.
Initially more heart muscle is good, but overall not sustainable.
what does the natriuretic peptide system impact + what are the 2 natriuretic peptides
- impacts salt and water handling, pressure regulation, and may influence myocardial structure and function
- BNP (brain natriuretic peptide)
- ANP (atrial natriuretic peptide)
BNP (brain natriuretic peptide)
a natriuretic hormone primarily released from the heart - particularly the ventricles
ANP (atrial natriuretic peptide)
a hormone released by the myocardial cells in the atria