Heart Failure Flashcards
definition of 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
Prevalence of HF
Affects 1-2% of UK population
Increasing in prevalence
prognosis of heart failure
Poor prognosis: 30-40% mortality at 1 year
10% HF patients readmitted within one month, most in one week
-50% HF patients readmitted over 3 months
More mortality than colon, breast, prostate cancer
longest hospital admission after stroke
symptoms of HF
breathlessness • Fatigue • Odema • Reduced exercise capacity
signs of HF
Odema • Tachycardia • raised JVP • chest crepitations or effusions • 3rdheart sound • Displaced or abnormal apex beat
diagnosis of HF
1.
Symptoms or signs of HF (rest or exercise)
and
2. Objective evidence of cardiac dysfunction
and (in doubtful cases)
3.Response to therapy (diuretics
investigations for cardiac dysfunction
ECHO
Radionucleotide Scan
Left Ventriculogram
Cardiac MRI
12 Lead ECG- LVSD very unlikely if ECG normal (90-95% sensitive). Problems with confidence of interpretation in primary care, must be entirely normalor else loses reliability
BNP (brain (B-type) natriuretic peptide)
Amino acid peptide, can be measured easily in blood, Elevated in heart failure, therefore low BNP effectively excludes heart failure
BNP
Highly sensitive test for HF, stable for up to 72hours, ‘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 • Caution… Can be elevated due to AF Elderly Valve Disease
structural heart diseases that may cause HF
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 egamyloid, HCM
Right ventricular failure: primary or secondary to pulhypertension
common causes of LV systolic dysfunction
• Ischaemic heart disease (usually MI) • Severe AV disesase or MR • Dilated cardiomyopathy(DCM): Means LVSD not due to IHD or secondary to other lesion ie valves/VSD
detailed evaluation of patients with LVSD
•
Take a detailed history:
•
it may provide the answer –ie MI, DM, HBP, post partum, alcohol etc
•
Hillwalkers…?lyme’s disease, IVDA…?HIV etc
•
Consider familial DCM: family history
•
Exclude renal failure, anaemia, TFTs
•
Possibly do autoantibodies / viral serology, ferritin
•
Consider need to exclude phaechromocytoma
•
Consider other causes……sarcoid, muscular dystrophy etc etc
•
ECG, CXR, always do an echo
•
Consider coronary angiography –essential if chest pain, patients <70(?)
•
CT coronary angiogram instead of cor angio
•
Consider evaluating for ischaemia/hibernation ie is revascularisation appropriate even if no angina
•
Cardiac MRI: infarction/inflammation/fibrosis
•
Most patients should be assessed by a cardiologist
why is echocardiography essential
• Identify and quantify • 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)
views on echo
parasternal long axis
parasternal short axis (papillary muscle level)
parasternal short axis (base)
LV ejection fraction
LV ejection fraction is a continuous biological variable
•
Disease / physiological changes can both decrease and increase the LVEF
•
The LVEF may be lower than previous but not pathologically low
hard to see on echo but good with MRI, time consuming
Normal 50-80% • Mild 40-50% • Moderate 30-40% • Severe <30%
biplane modified simpsons rule
Divides LV cavity into multiple slices of known
•
thickness
•
diameter
•
-> volume of each slice
•
= area x thickness(πr2 x thickness)
•
thinner slices -> more accurate volestimate
•
endocardial border traced accurately
•
often major technical difficulty with this method
•
but still one of most accurate method available
•
relatively easy to perform (but not routinely done)
LVEF -MUGA
ionising contrast used in scan of blood pumping in heart Much easier to obtain an accurate figure for the LVEF • Greater reproducibility • centre specific normal range But • Ionising radiation • No additional structural information
LVEF -MRI
Gold Standard for assessment of LVEF • Greater reproducibility • normal range • Added information about Aetiology • Fibrosis • Infiltration • Oedema • Valves • Time consuming –Approx 1 hour • Patient compliance • Long breath holds • Claustrophobic • Ability to lie flat • Specialist centres • Long waiting lists
Grading of heart failure
1-none
2- mild limitation and comfortable at rest or mild exertion
3-moderate limitation and comfortable only at rest
4-severe limitation and any physical activity brings on discomfort and symptoms occur at rest
Heart failure does not equal reduced cardiac output explanation
Normal heart (an orange) end diastolic volume 100mls with 60% EF = 60mls blood ejected per beat x 60 bpm = 3.6litres CO per min
•
Dilated heart (football): with reduced EF: EDV 200mls with 30% EF = 60mls blood ejected per beat x 60bpm = 3.6l CO per min….at 100bpm = 6 litres CO per min!
•
……and yet that person will possibly have severe heart failure….So it is NOT all about cardiac output
Modern Pharmacological treatment of heart failure (due to LV systolic dysfunction)
• Diuretics • Furosemide/Bumetanide • Symptomatic relief • ACE inhibitors/ARBs • Ramipril, enalapril • Candesartan/valsartan • Betablockers • Carvedilol/Bisoprolol • Aldosterone receptor blockers • Spironolactone/Eplerenone • ARNI’S • Entresto
Congestive Heart Failure
Heart failure is the state in which the heart is unable to pump blood at a rate commensurate with the requirements of the tissues or can do so only from high pressures
