Heart failure Basics (Boards and Beyond)
What is heart failure?
Impaired ability of the heart to pump blood
Pump becomes less efficient and water level in tank rises 
What happens when blood backs up?
LA pressure increases
increases pulmonary pressure
dyspnea
increases RA pressure
increases JVP
increases femoral pressure
pitting edema
Symptoms
dyspnea on exertion
heart is inefficient and cant pump blood to meet O2 demands, also high pressures in the lungs
Cough
high fluid pressure in lungs
PND
body retains some fluid
Orthopnea
lying flat is hard to breath
standing will pull fluid to base, lying flat moves fluid to lungs
Low flow signs: heart is so weak its can't pump enough blood forward
only occurs in systolic heart failure, sick heart w/ low EF
Loss of appetite
weight loss (cachexia)
confusion
cool extremities
RAAS
Liver produces Angiotensin
Kidneys produce Renin
Angiotensinogen converts to Angiotensin 1
AT1 converted by ACE to AT2
Roles of AT2
sympathetic
Renal NaCl resorption
arteriolar vasoconstriction
Adrenal aldosterone secretion #
Pituitary ADH secretion
Net result
NaCl and water retention
incr BP
incr preload
incr Afterload
none are good for the heart
Offset by some mechanisms
ANP
atrial stretch releases ANP
Vasodilator (slightly lowers SVR)
constricts renal efferents/dilates afferents
incr diuresis
helps blunt aldosterone effects in heart failure
in chronic overload, ventricle secretes ANP
not good enough to control RAAS
BNP
released by ventricular cells
both ANP and BNP rise w/ volume/pressure overload
Natriuretic proteins- incr GFR
BNP sometimes used for diagnosis in dyspnea
high levels assd w/ heart failure
Volume status
fall in CO
fall in effective circulating volume
volume of blood that is effective at perfusing tissues (low because blood is not putting enough blood into the arterial system)
stimulates RAAS
stimulates ADH release
NaCl retention
increase in TBW
the paradox: effective circulating volume is low while total body water is high
seen in HF and cirrhosis
Heart failure signs
elevated JVP
will see double bounce. Pressure at double bounce at sternal border is 5cm of water. add cm for each cm above sternal notch
Hepatojugular Reflux
pressing on abn just below the liver incr JVP 1-3cm in normal circumstances
greater response in RV failure
Rales
wet lungs, fluid filled alveoli pop open with inspiration
CXR shows congestion
Lungs can be clear in chronic HF
incr lymph drainage
S3
diastolic sound
high L atrial pressure pushing blood rapidly to LV
S4
diastolic sound
blood hitting stiff
L ventricle
displaced PMI
can cause cirrhosis
Diagnosis of HF
commonly typical signs/symptoms
Elevated BNP level
Definitive: Heart catheterization
increased LVEDP: L heart congestion
increased RA, RVEDP: R heart congestion
Pathophysiology
all forms of HF lead to decr CO
Activates 2 physiological systems
SNS
RAAS
system activation leads to
increased peripheral vascular resistance (vasoconstriction)
Retention of sodium/water (kidneys)
CO falls, leads to vasoconstriction
Angiotensin II, SNS
Therefore, TPR is always high in HF patients
BP may be hi or low
BP depends on combined effects of CO and TPR
Nesiritide
BNP analog
expensive won't work