Heart Failure Flashcards
whats heart failure
- inability of the heart to meet the demands of the body
what enables the heart to work as an effective pump? in terms of input and output
- input; one way valves -output; functioning muscle and chamber size
what does demand of heart mean?
- deliver a b volume carrying oxygen , glucose etc. that allows body tissues to function as required
what does guideline sat heat failure is?
- clinical syndrome of reduced cardiac output, tissue hypo perfusion , increased pulmonary pressure and tissue congestion
conditions that affect feature of the heart that c impaired cardiac function are?
- (one way) valves - functional muscle - chamber size
aetiology of HF
- (most commonly) IHD (coronary heart disease) - myocardial dysfunction (through fibrosis and remodelling of the heart - ^BP (hyt.) (2nd most common) -Aortic stenosis - arrhythmia (how well the chambers fill)(HFpEF) - cardiomyopathies - pericardial diseases
what are rare c of HF
- severe anaemia -sepsis - thyrotoxicosis (too much thyroid hormone) - d ^cardiac output ( heart cant deal w it even heart healthy )
^BP
- increase after load -major risk factor for MI wc can c HFd fibrosis (v ability to contract ) ( HFrEF)
how do we measure the ability of the heart to meet demands of the body
- CO = SV x HR
ejection fraction
- SV/EDV x 100 (usually presented as %) (50-70% normal)
what influences SV
- ^ preload ; pressure in ventricle before contracts (measure of b in ventricle STARLINGS LAW) -myocardial contractibility -negative influence ; after load (what heart pumps against ^BP/ stenosis ) TPR
draw starling law graph
image
what increases contractibility of the heart
SYMP activation (also increases HR)
why is CO reduced in heart failure
- v preload (d imparted filling of the heart when relaxed c v chamber size?) - v myocardial contractibility ( d failure with contractibility ) -^ after load (d stenosis + ^BP)
what 2 c of heart failure
- filling issue -contraction issue
what c filling issues
-ventricular volume/ capacity of b reduced - chamber stiff/ not relaxing enough - ventricular walls thicken (hypertrophied as they remodel) -EDV v d space in ventricle filling b is reduced
what c contractibility issues
-poor ventricular contraction no issue with space -systolic issue - muscle wall thin/fibrosed - chambers enlarged (overstretched sarcomere) -abnormal or uncoordinated myocardial contraction
how to classify HF
- HFrEF (systolic, contraction issue) (<50-70%EF) -HFpEF (diastolic , filling problem) (no contraction issue so fraction isn’t effected bu the numbers will be reduced)
how measure EF
-echo (b can see shape and size of chambers, + valves)
classifying HF according to ventricles
- LV = (most common bc additional RHF) - biventricular HF = congestive HF - chronic lung disease = RHF ( d areas of …)
starlings curve of HF
- in HFpEF = very little increase in CO, wc should increase in normal heart if you increase filling , eventually increasing b filling c v CO - resulting pulmonary. congestion
v CO does what?
- damage ventricle - v Vcontraction -v SV -r CO - activation of neurohormonal system
neuro-hormonal system
- baroreceptors (carotid sinus) detect the v BP - c ^ sympathetic drive ( ^ HR, ^ TPR -= ^ afterload = ^ CO - heart is alrady struggling so ^ damage than good , and ^ demand b ^ 02 required - also activates the RAAS b kidney sense it as result of v renal perfusion - c brain = corticotropin , ADH - c adrenal = aldosterone -c bv = vasoconstriction - c kidney = Na=reab. -c ^ preload and ^ afterload
clinical symptoms
- fatigue/ lethargy - breathlessness ( when lying flat d RHF) - peripheral oedema (RHF) - pulmonary oedema (LHF)
why does oedema occur
- d ^ VP = ^ capillaries so blood moves out the capilarry into interstitial space = oedema - LHF - back load of blood from v -> A -> backs up into pulmonary system (pulmonary cant deal with too much ^ hydrostatic p) and so b moves into the pulmonary interstitial space c pulmonary oedema [ RHF; RV->rA) -listen to this again
raised jugular venous pressure
- indication of the RHF
similaries bw RHF and LHF
image of tabel
whats seen on a xray of congestive heart failure
upper lobe diversion (dilated pulomary veins)
cardiomegaly
pleural effusion
alveolar oedema
pain radiating to between the shoulder blades
aoric dissection
