heart failure Flashcards
what is stroke volume?
how many ml of blood is pumped per contraction
what initial blood tests would you do in someone presenting with oedema and why?
U+E: renal disease could lead to increased excretion of proteins
LFT and GGT -liver disease could lead to decreased synthesis of proteins
FBC
TFTs -hypothyroidism can cause oedema and fatigue
pro-BNP
what affects stroke volume?
preload
contractility
afterload
what is preload and what affects it?
end diastolic volume -amount of blood filling up ventricle before contracting-affected by venous return, fluid volume, ability of atria to contract and pass blood to ventricles
what affects contractility of heart muscle?
increase -positive inotropes eg noradrenaline
decrease -negative inotropes, beta blockers, CCBs
what is afterload and what affects it?
pressure required to pump blood from heart into arterial system -affected by BP, atherosclerosis, aortic valve stiffness
what is cardiac output and the equation for it?
amount of blood heart pumps out per minute
stroke volume x heart rate
what is ejection fraction and equation for it?
% of total blood in ventricle that gets pumped out by each systolic contraction
stroke volume/total ventricular volume
what is normal ejection fraction (EF)?
50-70%
what are the 3 types of heart failure (classified by ejection fraction) and their EFs?
1) systolic HF -HF with reduced ejection fraction -EF <40%
2) heart failure with mildly reduced ejection fraction -41-49%
3) diastolic HF -HF with preserved ejection fraction (hefpef) -EF>50%
what happens in HF with impaired ejection fraction and an example of a cause?
inability of ventricles to properly contract resulting in decreased cardiac output, eg IHD
what happens hefpef and examples of causes?
inability of ventricles to contract therefore fill properly
cardiac tamponade, restrictive cardiomyopathy, constrictive pericarditis
what happens in cor pulmonale/pulmonary heart disease?
enlargement and failure of right ventricle of heart as response to increased vascular resistance/ high BP in lungs. can happen due to respiratory disorder or buildup from left heart failure.
what are the 2 situations from which acute heart failure can arise?
1) previously healthy heart where something has caused in to fail
2) acute decompensation of already known heart failure
what are some triggers of acute heart failure?
ACS
tachys
PE
severe HTN
infection
drugs eg NSAIDs, steroids
not taking usual meds /dietary restrictions
renal insufficiency
how can acute heart failure be classified?
warm/cold -how peripherally perfused patient is
wet/dry -how fluid overloaded they are
what are some signs of poor peripheral perfusion?
low BP
cool peripheries
prolonged CRT
reduced UO
what are some signs of fluid overload?
pulmonary oedema -bibasal coarse crackles
raised JVP
peripheral oedema
what is he prognosis and management principle of warm and dry acute HF?
best prognosis
optimise meds and treat triggers
what is the management strategy of warm and wet acute HF?
give diuretics +/- vasodilators
what is the management strategy of cold and dry acute HF?
consider fluid bolus, may need inotropes
what is the prognosis and management strategy for cold and wet acute HF?
worst prognosis
consider diuretics if BP>90
may need vasopressors/inotropes
what are the symptoms of left heart failure?
congestion in lungs causing pulmonary oedema:
dyspnoea
orthopnoea
PND
cough
cardiac wheeze (wheeze caused by heart issues)
what are some signs of right HF?
ankle oedema
raised JVP
ascites