Chronic heart failure Flashcards
Define heart failure
A 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 - underlying condition that is causing it
prevalence of HF in UK?
1-2 %
why is the prevalence of HF in the UK increasing?
due to:-
treatment of AMI (heart attack)
aging population
incidence/prevalence of things like hypertension, CHD, obesity, diabetes
what is the one-year survival rate for heart failure worse than?
breast cancer
uterus
prostate
bladder
What can be said about re-admission rates for HF?
High! and readmission is most likely to happen early.
Length of hospital admission is longer than any other condition.
What are the symptoms of heart failure?
breathlessness
Fatigue
Odema
Reduced exercise capacity
What are the signs of heart failure?
Oedema
Tachycardia
Raised JVP
Chest crepitations or effusions
3rd Heart sound
Displaced or abnormal apex beat
Is heart failure easy to diagnose based on clinical signs alone?
no, it is very difficult!
diagnosis incorrect in approximately 40-50% of cases
3 things you need to consider to diagnose heart failure?
Symptoms or signs of HF (rest or exercise)
Objective evidence of cardiac dysfunction (in doubtful cases)
Response to therapy (diuretics)
what tests can give objective evidence of a diagnosis of HF?
ECHO - key, may show cause ie MI, valvular heart disease
Radionucleotide Scan
Left Ventriculogram
Cardiac MRI
potential screening tests for heart failure
12 Lead ECG
BNP (brain (B-type) natriuretic peptide
what is a 12 Lead ECG and how does it give evidence of heart failure?
test that uses 10 electrodes to generate 12 different views of the heart’s electrical activity.
LV Systolic Dysfuntion very unlikely if ECG normal (90-95% sensitive)
• Problems with confidence of interpretation in primary care, must be entirely normal or else loses reliability
what is BNP and how does it give evidence of heart failure?
BNP is a hormone secreted by cardiomyocytes in the heart ventricles in response to stretching caused by increased ventricular blood volume.
BNP levels go up in heart failure
why is BNP a good test?
Highly sensitive test for HF, stable for up to 72 hours, ‘bedside’ testing available if desired, relatively inexpensive
Low BNP effectively rules out heart failure or LVSD, elevated BNP indicates need for an echo/cardiac assessment
what other reasons are there for an elevated BNP?
AF
Elderly
Valve Disease
What investigations/tests are carried out to look for CHF/HF? (7)
FBC - BNP levels - raised in HF ECHO fasting blood glucose serum urea electrolytes urinalysis - myoglobin thyroid function CXR
what things are you looking for in the clinical examination for HF diagnosis? (5)
rales - abnormal lung sounds - discontinuous clicking/rattling
bilateral ankle oedema
heart murmur
jugular venous dilatation
laterally displaced/ broadened apical beat
Give examples of structural heart diseases that, if severe enough, can cause heart failure?
LV systolic dysfunction – many causes
Valvular heart disease
Pericardial constriction or effusion
LV diastolic dysfunction/heart failure with preserved systolic function/heart failure with normal ejection fraction
Cardiac arrhythmias: tachy or brady
Myocardial ischaemia/infarction (usually via LVSD)
Restrictive cardiomyopathy eg amyloid, HCM
Right ventricular failure: primary or secondary to pul
hypertension
Causes of LV systolic dysfunction
ischaemic heart disease
severe Aortic Valve disease or MR
Dilated cardiomyopathy (DCM): Means LVSD not due to IHD or secondary to other lesion ie valves/VSD
Inherited • Toxins: eg alcohol, catecholamines (phaeochromocytoma or stress cardiomyopathy (takosubo’s cardiomyopathy) • Viral: acute myocarditis or chronic DCM • Other infective: HIV, chaga’s disease, Lyme’s disease....... • End stage hypertrophic cardiomyopathy • End stage arrhythmogenic RV cardiomyopathy • Systemic disease: sarcoidosis, haemachromatosis, SLE, mitochondrial dis. • Muscular dystrophies • Peri-partum cardiomyopathy • Hypertension • Isolated non compaction • Tachycardia related cardiomyopathy • RV pacing induced cardiomyopathy
How do you figure out which type of heart failure is present? Ischaemic heart disease (IHD), valvular disease or dilated cardiomyopathy
take a detailed history
ECG, CXR, always do an echo
Most patients should be assessed by a cardiologist
why is echocardiography such an essential investigation?
gives images of the heart
it enables you to identify and severity of heart problem:-
• LV systolic dysfunction
• Valvular dysfunction
• Pericardial effusion / tamponade
• Diastolic dysfunction
• LVH
• Atrial/ventricular shunts / complex congenital heart
defects
• Pulmonary hypertension / Right heart dysfunction
May not identify constriction / may miss shunts
(but you will see atrial dilatation)
what is the LV ejection fraction
the amount of blood that actually gets pumped out by the LV during systole as a % of the total blood in the LV
what can change the LVEF?
Disease / physiological changes can both decrease and increase the LVEF - it is however a continuous biological variable like haemoglobin / anaemia
why can it be very difficult to quantify the LVEF accurately
and reproducibly by echo?
Quality of images
Experience of operator
Calculation method of LVEF – M-mode, Simpson’s biplane
Use of contrast agents
Time-consuming to perform accurately
Normal range is centre specific, but LVEF not routinely
measured and NR not routinely established
Normal value for ejection fraction?
50-80%
value for mild ejection fraction
40-50%
moderate ejection fraction value
30-40%
severe ejection fraction value?
<30%
what is a MUGA scan?
scan using ionising radiation to help measure LVEF
Pros:-
It is much easier to obtain an accurate LVEF
greater reproducibility
cons:-
ionising radiation
no additional info about structure of the heart
what is the gold standard investigation for LVEF
MRI scan
pros and cons for MRI scan to investigate LVEF?
Pros:- Greater reproducibility normal range Added information about Can see cause of LV problem such as • Fibrosis • Infiltration • Oedema Can see heart valves
Cons:- Time consuming – Approx 1 hour Patient compliance Long breath holds Claustrophobic Ability to lie flat Specialist centres Long waiting lists
class 1 and 4 of NYHA classification of heart failure?
class 1 - no limitation on exercise tolerance, symptoms- no symptoms during usual activity
class 4 - severe limitation, symptoms - any physical activity brings on discomfort and symptoms occur at rest
treatment/therapy for heart failure due to LV systolic dysfunction
diuretics
ACE inhibitors/ ARBs (Angiotensin II receptor blockers)
Beta blockers - carvedilol/bisoprolol
Aldosterone receptor blockers
ARNI’s (angiotensin receptor-neprilysin inhibitor)
Give 1 example of ARNI’s medication?
Entresto
Give 4 examples of ACE inhibitors/ ARBs (Angiotensin II receptor blockers)
Ramipril
enalapril
candesartan
valsartan
give 2 examples/types of diuretic medication used for heart failure?
furosemide
bumetanide
Why does cardiac output not mean heart failure?
because someone can have a higher cardiac output than a normal person due to for example LV dilatation and yet this person could have severe heart failure
