C5: CHF Flashcards
define heart failure
a state in which the heart is unable to meet the oxygen and metabolic demands of the body
symptoms may be present in a rest state or w/ exertion
define heart function
producing a cardiac output sufficient enough to meet all physiological needs and to generate arterial press sufficient to profuse all organs (under low pressure)
do compensatory mechanisms for heart failure help or hurt?
hurt
can we diagnose CHF on echo?
no, its diagnosed clinically based on signs and symptoms, we look for cause and grading
1 year mortality rate for severe, moderate and mild CHF
S: 50-60%
Mod: 15-30%
Mild: 10%
3 general causes left heart failure
diseases of:
the myocardium
valves
coronary arteries
what causes right heart failure
Lft heart faliure
diseases of:
the lung parenchyma (COPD, emphysema)
lung vascularity (emboli, HTN)
cor pulmonale
most common cause of right heart failure
left heart failure, due to rising pressures, R heart fails b/c it cant handle the high afterload
describe some causes of decreased myocardial function that cause LHF
decreased myocardial function - CAD, CMO, myocarditis, infitrative diseases (hemochromatosis, amyloidosis, sarcoidosis), vascular diseases, medicatins, radiation therapy
describe some causes of increased myocardial workload that cause LHF
HTN
valvular diseases (severe regurg/stenosis)
increase preload/afterload
does LHF eventually cause RHF
yes
2 types of heart faliure
systolic/forward HF
diastolic/backwards HF
another term for systolic/forward HF and diastolic/backwards HF
S/F: Heart Failure reduced EF (HFrEF)
D/B: Heart Failure normal EF (HFnEF)
which type of HF is reversible to some extent?
diastolic…. systolic is not reversible
can LHF be both systolic or diastolic
yes, often there is an element of both in one patient
can diastolic HF be isolated? (w/o systolic HF)
yes, diastolic HF can be isolated
w/ systolic HF there will ALWAYS be a component of diastolic HF
what is the EF w/ SHF
how will CO be effected
<40%
CO will also be decreases
what is the EF w/ DHF
how will CO be effected
> 55%
CO will be normal
what causes SHF
what is the most common cause
impaired ventricular contraction - most CHF are this type (50-60%)
ischemic heart disease
what causes DHF
what is the most common cause
impaired ventricular relaxation
40-50% of CHF cases
HTN and LVH
causes of impaired ventricular relaxation of the LV
reduced compliance and possibly LVH….
…infiltrative myocardial disease, LVH by AS, high BP, advanced age
describe the physiology of DHF of the LV
reduced compliance of the LV leads to increased LVEDP and LA filling pressures (Gr 2/3 DD), which translates into higher pressure backing up in the PVs , lungs and eventually to the R heart
symptoms of both types of LV CHF
dyspnea due to pulm. congestion
orthopnea - diff breathing laying down
parxysmal nocturnal dyspnea - diff breathing at night
acute pulnomary edema
chronic fatigue
palpitations
what is the most common palpitation/arrhythmia to experience w/ CHF
afib
signs of both types of LV CHF
cardiomegaly
ventricular heave - LV pushes against chest wall
3rd and 4th heart sound
rales or crackles when breathing
cheyne-stokes respiration - w/ end stage CHF - starting and stopping breathing
tachycardia to compensate for low volume output
what causes the 3rd and 4th heart sound
3rd - early filling
4th - decreases compliance
signs of RHF
signs related to underlying disease RV hypertrophy murmur due to pulm. or TV regurg wheezing and SOB elevated jugular venous pulse (JVP) pitting edema, ascites, cyanosis
symptoms of RHF
main symp. related to systemic venous congestion (JVP or leg edema) fatigue when CO is reduced dependent edema liver enlargement/RUQ pain anorexia or bloating
whats the gold standard for measuring pulmonary pressure
what is its downside
pulmonary capillary wedge pressure
its invasive, where as echo is not, but we canonly estimate LAP
how is pulmonary capillary wedge pressure measures
catheter is inserted into the R heart through the femoral vein or wrist and advanced into the RA, RV, RVOT, PA and then into a smaller pulmonary vessel
another term for LAP
PWCP - pulmonary wedge capillary pressure
norm LAP
an LAP over what value is considered hypertension
3-12 mmHg
> 18 mmHg
NYHA functional CHF categories
Grade I - no symp and no limitations w/ norm activity
Grade II - mild symp or some limitations, can engage in low levels of excercise and comfortable at rest
Grade III - marked limitations w/ activity but comfortable at rest
Grade IV - severe limitations w/ symptoms are rest
review pressure/volume loops for SHF and DHF
pg 18 and 19 of PP
how does SHF and DHF effect frank starling law
FSL is lost in both SHF and DHF b/c of the lack of compliance
what does the term left heart venous return refer to
pulmonary venous return
3 things that effect venous return
blood volume (obesity, preg, blood loss) venous press (related to volume, venous constriction and temp) intrathoracic press
does expiration increase or decrease venous return fro the lower extremities
increases
how does high after load reduce stroke volume
by increasing the end systolic volume in the LV
the parasympathetic nervous sys stimulates which areas of the heart
what pathway does it use
SA node and AV node (decreased HR)
vagus nerve
the sympathetic nervous sys stimulates which areas of the heart
what pathway does it use
SA node, AV node and purkinje fibers (increases HR)
cardiac fibers/nerves
how does the parasympathetic nervous sys slow HR
by moving the resting membrane potential to a more negative state… sympathetic does the opposite
what determines HR
steepness of phase 4 slope
as BP drops, what happens to HR, contractility and blood vessles
increased HR
increased contractility
systemic vasoconstriction
relationship b/w vasoconstriction and BP
inversely related
why do compensatory mechanisms kick in w/ CHF
are they helpful
to counter act a drop in EF and BP, they are helpful in the short term but eventually make CHF worse
how does sodum and h20 retension effect contractility of the heart
makes it harder for the heart to contract
which hormones are released in order to counter act the compensatory mechanisms
what are the effects of these hormones
atrial natriuretic peptide
B-type natriuretic peptide (tested to see if someone is in CHF)
water excresion and vasodilation
which specific parameters are we assessing when scanning a patient in CHF
underlying etiology chamber sizes and LV/RV mass systolic function diastolic filling press R side heart pressure valve function
concentric LVH is seen more often with which type of CHF
backward
concentric is thick walls, norm chamber size
eccentric LVH is seen more often with which type of CHF
fowards
eccentric is normal wall thickness, dilated chamber
what do we need to determine RAP
IVC sniff test
TR jet
how do we find RVSP
4(v)^2 + RAP
how can moderate or severe regurg OR stenosis cause heart failure
it alters preload and afterload significant;y which puts stress on the heart
treatment for CHF
depends on causes and symptoms
lifestyle
medication
pacemakers
goal of medical treatments for CHF
mitigate symptoms to improve quality of life and improve the patients NYHA classification if possible…
… also to balance the effects of the compensatory mechanisms
how do diuretics work
how do they help w/ CHF
-promote urination to decrease blood volume
- decrease preload and afterload
- relieves pulmonary congestion/pedal edema
- also to treat high BP by decreasing blood volume
what are inotropic agents
when are they used
improve contractility of the heart
used for those w/ reduced EF to increase SV and stimulated viable wall segments to contract
will necrotic heart tissue respond to inotropic agents
no
examples of inotropic agents
digitalis, digoxin
describe ACE inhibitors
what is there effect
angiotension converting enzyme blocker
-used for arterial and venous vasodilation effects… this drug would increase BP
…. look for drugs ending in “pril” (enalopril, captopril)
describe beta blockers
when would they be used
slow the force of contractions and HR
used in patients w/ diastolic HF…. controversial in patients w/ low EF since they can decrease SV futher
do beta blockers increase the hearts filling time
yes
examples of beta blockers
propranolol, atenolol, metoprolol…. names ending in olol
drugs used for arrhythmias
anti-arrhythmias like calcium channel blockers, lidocaine, beta blockers
prophylactic anticoagulation for a fib - to reduce risk of clots
which arrhythmia is common in CHF
describe its effects
a fib, it decreases SV and leads to a risk of clot formation and ventricular arrhythmias.
non medical anti-arrhythmic treatments
- pacemakers -biventricular pacing
- implantable cardioverter/defibrillators (ICD) - stops v fib and v tachycardia
- LV assist device (LVAD) - can be temporary of permanent w/ internal or external pumps
LVADs are good for which type of HF
forward/SHF
