heart failure Flashcards
what is the ejection fraction?
what is the equation?
what is the typical ejection fraction?
when does ejection fraction change ?
fraction ejected in a single heart bear of total volume avaliable (EDV)
SV/EDV
50-60%
when there is an ejection problem
what are the 3 determinants of stroke volume?
why does CO increase with EDV?
what improves myocardial contractility ?
what does an. increase in afterload do to SV?
pre load
myocardial contractility
after load
increased EVD = increase preload = increase stretch = increase contractility and stroke volume
sympathetic nervous stimulation
lowers SV
what is the definition of heart failure?
what is the most common cause of HF?
other common causes?
what is high output heart failure?
a clinical syndrome pf reduced cardiac output, tissue hypofusion, increased pulmonary pressure and tissue congestion - a collection of signs and symptoms arising from impairment of filling or emptying
ischaemic heart disease
hypertension, valvular disease (structural)
a rare cause ofheart failure due to increased demand e.g. sepsis/thyrotoxicosis
what is remodelling?
loss of myocyte de to fibrosis in response to ischaemic heart disease and hypertension resulting in impaired contractility and or filling due to chnages in shape and size
what is HFrEF?
what chnages to heart causes it?
is the space reduced?
heart failure due to reduced ejection fraction - systolic ejection problem
cannot pump with enough force
muscle wall thinned/fibrosed, chamber over stretched so sarcomeres dont overlap anymore, uncoordinated contraction
not reduced but poor contraction
what is HFpEF?
what changes in the heart leads to this?
is the space in ventricles reduced?
heart failure with preserved ejection fraction - diastolic/filling problem
ventricular chambers too stiff
ventricular walls thickened
space is reduced - EDV reduced
what is the ejection fraction like HFrEF and HFpEF?
what side of heart failure is more common?
what is it called when both sides fail?
what is the most common cause of right sided HF?
HFrEF = ejection problem = reduced ejection fraction
HFpEF = normal ejection fraction - it is still a problem as EDV is reduced but the proprtion of what is ejected is mainatned
left
biventricular/ cogestive heart failure
left ventricular heart failure - leads to right failure
what are symptoms of heart failure?
where would you get oedema in LV HF?
where would you get oedema in RV HF?
why do you get oedema ?
- dysponea
- fatigue
- exercise tolerance
- oedema
pulmonary
peripheral e.g. limbs
increase pressures in ventricles as they fail to eject blood = back log of pressure in veins = higher hydrosttic pressure in capillaries = more favourable for fluid to leave BV = oedema
why is it important to do an echocardiogram?
what is the more common type of HF?
whats it called?
confirms diagnosis
identifies causes e.g. valvular stenosis
can identify what typeof heart failure which can chnage treatment and prognosis
HFrEF in left ventricle
left ventricular systolic dysfunction
what does the body do in response to low CO from HF?
why is it bad?
neuro-hormonal activation
low BP = inc sympathetic drive = HR and BP up = inc afterload and workload
low BP = low renal perfusion = RAAS = AGII= more fluid retention and vasoconstriction = inc preload and afterload = inc work load
also cordiotoxic effects from long term sympathetic activation
it ultimately leads to increase cardiac demand = further deterioration and reduced SV/CO
summary of neuro hormonal effects
what would you see on a X ray in someone with HF?
what would you hear in the chest?
other Sx?
pulomary oedema = opacity due to fluid
basal pulmonary crackles
dyspnoea
orthopnoea = wrose brethelessness when breathing
paroxysmal nocturna dyspnoea = waking from sleep breathless
what would you see in right sided HF?
why is right failure commonly seen after left failure?
left Vs right HF?
raised jugular venous pressure and peripheral oedema
LV failure = backlog = inc pulmonary pressure = inc RV afterload = failure
