Chronic Heart Failure Flashcards
Define heart failure
A clinical syndrome comprising of dyspnoea, fatigueor fluid retention due to cardiac dysfunction, either atrest or on exertion, with accompanyingneurohormonal activationnot 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 populationincidence/prevalence of things like hypertension, CHD, obesity, diabetes
what is the one-year survival rate for heart failure worse than?
breast canceruterusprostate 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?
breathlessnessFatigueOdemaReduced exercise capacity
What are the signs of heart failure?
OedemaTachycardiaRaised JVPChest crepitations or effusions3rd Heart soundDisplaced 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 diseaseRadionucleotide ScanLeft VentriculogramCardiac MRI
potential screening tests for heart failure
12 Lead ECGBNP (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 inexpensiveLow 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?
AFElderlyValve Disease
What investigations/tests are carried out to look for CHF/HF? (7)
FBC - BNP levels - raised in HFECHO fasting blood glucoseserum ureaelectrolytesurinalysis - myoglobinthyroid functionCXR
what things are you looking for in the clinical examination for HF diagnosis? (5)
rales - abnormal lung sounds - discontinuous clicking/rattlingbilateral ankle oedemaheart murmurjugular venous dilatationlaterally displaced/ broadened apical beat
Give examples of structural heart diseases that, if severe enough, can cause heart failure?
LV systolic dysfunction – many causesValvular heart diseasePericardial constriction or effusionLV diastolic dysfunction/heart failure with preserved systolic function/heart failure with normal ejection fractionCardiac arrhythmias: tachy or bradyMyocardial ischaemia/infarction (usually via LVSD)Restrictive cardiomyopathy eg amyloid, HCMRight ventricular failure: primary or secondary to pulhypertension
Causes of LV systolic dysfunction
ischaemic heart diseasesevere Aortic Valve disease or MR Dilated cardiomyopathy (DCM): Means LVSD not due to IHD or secondary to other lesion ie valves/VSDInherited• Toxins: eg alcohol, catecholamines(phaeochromocytoma or stresscardiomyopathy (takosubo’scardiomyopathy)• Viral: acute myocarditis or chronicDCM• Other infective: HIV, chaga’sdisease, Lyme’s disease…….• End stage hypertrophiccardiomyopathy• End stage arrhythmogenic RVcardiomyopathy• Systemic disease: sarcoidosis,haemachromatosis, SLE,mitochondrial dis.• Muscular dystrophies• Peri-partum cardiomyopathy• Hypertension• Isolated non compaction• Tachycardia relatedcardiomyopathy• RV pacing inducedcardiomyopathy
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 echoMost patients should be assessed by a cardiologist
why is echocardiography such an essential investigation?
gives images of the heartit 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 heartdefects• Pulmonary hypertension / Right heart dysfunctionMay 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 accuratelyand reproducibly by echo?
Quality of imagesExperience of operatorCalculation method of LVEF – M-mode, Simpson’s biplaneUse of contrast agentsTime-consuming to perform accuratelyNormal range is centre specific, but LVEF not routinelymeasured and NR not routinely established
