Heart failure diagnosis and intervention Flashcards
what is heart failure
clinical syndrome comprising of dyspnoea, fatigue or fluid retention due to cardiac dysfunction, either at rest or on exertion, with accompanying neurohormonal activation. not a final diagnosis - “heart failure due to …”
one year survival rate for heart failure is worse than that for cancer of
breast, uterus, prostate, bladder
readmission rate within first 12 weeks
30%, lessens as the weeks go on
morbidity and mortality rates are
high
symptoms of heart failure
breathlessness, fatigue, oedema, reduced exercise capacity
signs of heart failure
oedema, tachycardia, raised JVP, chest crepitations or effusions, 3rd heart sound, displaced apex beat
what is needed for diagnosis or heart failure and why
symptoms, evidence of cardiac dysfunction and response to treatment. because clinical signs are not specific enough and some patients have symptoms only and no signs. diagnosis incorrect in 40-50% of cases
obtaining objective evidence of cardiac dysfunction
echocardiogram, radionuclide ventriculography, MRI, left ventriculography
screening tests
12 lead ECG, BNP- high level means high likelihood of heart failure, helps to reduce echo waiting lists
causes of heart failure
if sufficiently severe almost any structural cardiac abnormality will cause heart failure eg MI, valvular heart disease, cardiac arrhythmia
causes of left ventricular systolic dysfunction
ischeamic heart disease or dilated cardiomyopathy which means LVSD not due to IHD or secondary to other lesion ie valves/ VSD
diagnostic evaluation of LVSD
detailed history, autoantibodies, viral serology, consider other causes eg sarcoid, muscular dystrophy, do an ECG sometimes CXR always do an echo, consider coronary angiography if chest pain, evaluate for ischaemia or hibernation, cardiac MRI to look for infarction or inflammation or fibrosis, refer to cardiology
why is echocardiography essential
identifies and quantifies many illnesses eg LV systolic dysfunction, valvular dysfunction, diastolic dysfunction, shunts, may not identify constriction and may miss shunts but you will see atrial dilatation, reasonably inexpensive
LV ejection fraction
disease and physiological changes can both decrease and increase lvef. it may be lower than previous but not pathologically low, analogous to haemoglobin/ anaemia
why is LV ejection fraction hard too quantify with echo
quality of images, experience of operator, calculation methods vary- Simpsons biplane is best, use of contrast agents, can be time consuming to perform accurately
ejection fraction ranges
normal 55-70%, mild 40-55, moderte 30-40, severe less than 30
biplane modified Simpsons rule
divides LV cavity into multiple slices of known thickness and diameter, endocardial border traced accurately. often major technical difficulty with this method but still one of the most accurate methods available and relatively ray to perform but not routinely done
LVEF- MUGA scan
much easier to obtain an accurate figure for the LVEF, greater reproducibility, ionising radiation, no additional structural information, centre specific normal range
cardiac MRI
more accurate than echo, additional information of tissue characteristics, expensive and time consuming, cannot be done at bedside, requires breathholding, claustrophobia issues
left ventricular systolic function is a potent predictor of
death in hospitalised heart failure patients
grading of heart failure
NYHA class I no exercise limitation, no symptoms during usual activity, class ii mild limitation, comfortable with rest or mild exertion, III moderate limitation, comfortable only at rest, IV severe limitation, any physical activity brings on discomfort and symptoms occur at rest
prognosis for NYH4 compared to NYH3
significantly worse
how to grade severity of HF
degree of LV impairment, NYHA class ie severity of symptoms, degree of elevation of BNP
heart failure does not equal
reduced cardiac output
systemic effects of heart failure
HF is a systemic disorder. cardiac dysfunction, renal dysfunction, skeletal muscle dysfunction, systemic inflammation, neurohormonal activation (mostly maladaptive)
effects of heart failure on renin- angiotensin- aldosterone system
salt and water retention, adverse haemodynamics, LV hypertrophy/remodelling and fibrosis, hypokalaemia and hypmagnesaemia
effects of heart failure on sympathetic nervous system
arrhythmogenic, adverse haemodynamics, increases renin
treatment of heart failure due to LVSD
block the neurohormonal response. using ACE inhibitors, beta blockers, alderosterone receptor blockers, angiotensin receptor and neprolysin inhibitor
