33. Heart Failure Flashcards
Define cardiac 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.
Is heart failure a final diagnosis?
- No, it’s not a final diagnosis
- term should be qualified by the underlying structural abnormality and cause e.g. heart failure due to l.ventricular systolic dysfunction (LSVD) due to ischaemic heart disease or heart failure due to severe aortic stenosis
What is the prevalence of heart failure and l. ventricular systolic dysfunction?
0.4-2% (for both heart failure and LVSD)
What does heart failure likeliness increase with?
Increases with age (mean age is mid 70s)
Is heart failure more common in men or women?
Women (on average)
What factors increase risk of cardiac heart failure? (6)
- obesity
- diabetes
- hypertension
- coronary heart disease
- hyperlipidaemia
- age
- treatment of acute MI
For which cancers is one year survival rate worse for heart failure than that of these cancers? (4)
- breast
- uterus
- prostate
- bladder
What are the biggest costs of heart failure treatment from most to least expensive? (5)
- hospital inpatient care (largest cost)
- primary care
- drugs
- hospital outpatient care
- outpatient investigations
What is the general link between heart failure and re-admission hospital rates?
has very high re-admission rates especially at early stages of cardiac failure (30% chance) (patient likely to be re-admitted again)
What are the symptoms for cardiac failure? (4)
- breathlessness
- fatigue
- oedema
- reduced exercise capacity
What are the signs for cardiac failure? (6)
- oedema
- tachycardia
- raised JVP
- chest crepitations
- 3rd heart sound (S3)
- displaced or abnormal apex beat
What can be seen on a chest x ray in heart failure patients?
Big enlarged heart (due to congestion)
Why should objective evidence of cardiac dysfunction be needed in cardiac failure patients?
- Because diagnosis is incorrect in approx. 40-50% patients.
- Symptoms not specific and signs insensitive
What are 3 main rules for diagnosing someone with cardiac failure according to European cardiology guidelines?
- Symptoms or signs of heart failure (rest or exercise)
- Objective evidence of cardiac dysfunction (and in doubtful cases)
- Response to therapy (diuretics)
What investigations need to be done to diagnose cardiac failure/dysfunction? (4)
- echo(cardiography)
- radionuclide ventriculography (RNVG/MUGA)
- MRI
- left ventriculography
- 12 lead ECG
- BNP (brain B type natriuretic peptide); blood test
Why is echo the most common screening method for cardiac failure?
No radiation and practical but wait can take up to 3-6 months
What are the pros to 12 lead ECG? (1)
- l.ventricular systolic dysfunction unlikely if ECG normal (90-95% sensitive)
What are the cons to 12 lead ECG? (1)
- problems with confidence of interpretation in primary care (must be entirely normal or else loses reliability)
What are the pros to BNP test? (Brain B type natiruretic peptide) (5)
- amino acid peptide can be measured easily in blood
- elevated in cardiac failure (therefore low BNP excluded heart failure)
- highly sensitive test for heart failure
- stable for up to 72 hours bedside testing available
- inexpensive
What are the BNP levels like in healthy hearts?
Low in healthy hearts
What does BNP naturally do in the body?
- secreted by the ventricles in response to excessive stretching of the heart
- decreases resistance and central venous pressure
- increases natriuresis (Na excretion in the urine)
- vasodilation
- increases excretion of water
- decrease in cardiac output
What does low BNP test result mean? (2)
- rules out heart failure
- rules out l.ventricular systolic dysfunction (LVSD)
What does high BNP test result mean?
There is a need for echo/cardiac assessment
What can ultimately lead to heart failure?
If sufficiently severe, almost ANY structural cardiac abnormality or malfunction can lead to heart failure
What is the most common aetiology for cardiac failure? (8)
- l. ventricular systolic dysfunction (LVSD)
- valvular heart disease
- pericardial constriction or effusion
- l. ventricular 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 e.g. amyloid, hypertrophic cardiomyopathy
- right ventricular failure’ primary or secondary or hypertension
How to calculate the ejection fraction of the heart?
Stroke volume/ (end diastolic volume)
stroke volume= the volume of blood pumped out by ventricle
end diastolic volume= volume of blood in r. or l. ventricle just before systole or filling in
What is the main aetiology for l.ventricular systolic dysfunction? (3)
- ischaemic heart disease (usually MI)
- dilated cardiomyopathy (means LVSD is not due to ischaemic heart disease or secondary to other lesion e.g. valves or ventricular septal defects)
- severe aortic valve disease or mitral regurgitation
What features of dilated cardiomypathy can lead to l. ventricular systolic dysfunction (LVSD) eventually? (13)
CM= cardiomyopathy
- inherited
- toxins (eg. alcohol, catecholamines, stress CM; takosubo’s CM, phaeochromocytoma)
- viral (acute myocarditis or chronic dilated CM)
- other infective (e.g. HIV, chaga’s disease, Lyme’s disease)
- Systemic disease (e.g. sarcoidosis, haemachromatosis, mitochondrial disease, systemic lupus erythematosus)
- muscular dystrophies
- peri-partum CM
- hypertension
- isolated non compaction (rare CM)
10 .tachycardia (related to CM) - r.ventricular pacing induced CM
- end stage hypertrophic CM
- end stage arrhythmogenic r. ventricular CM
What parts of the patient history should be carefully evaluated when diagnosing patients with l.ventricular systolic dysfunction? (6)
- Past medical history; MI, diabetes, hypertension, post partum, alcoholism?
- Social history: hillwalkers and Lyme’s, HIV, Iv drug user?
- Family history: dilated cardiomypathy?
- Exclude renal failure, anaemia, thyroid function tests
- Exclude phaecromocytoma (tumour which may lead to very dangerous high BP)
- Consider other causes: sarcoid, muscular dystrophy etc
What investigations should be done for l.ventricular systolic dystrophy? (7)
- ECG
- chest x ray
- Echo (ALWAYS)
- coronary angiography (esp. if elderly and chest pain)
- CT coronary angiogram
- cardiac MRI (infarction ,inflammation, fibrosis?)
- consider revascularisation (even if no angina)
What disease should always be ruled out when making a l.ventricular systolic dysfunction diagnosis?
coronary heart disease
What features should always be looked at in detail in an echo when diagnosing with l.ventricular systolic dysfunction?
- l. ventricular systolic dysfunction
- valvular dysfunction
- pericardial effusion/ temponade
- diastolic dysfunctions
- l.ventricular hypertrophy
- atrial/ventricular shunts (complex congenital heart defects)
- pulmonary hypertension (right heart dysfunction/failure; cor pulmonale)
What does right heart failure lead to in the lungs?
pulmonary hypertension
What will be seen straight away in an echo that can be an indication of l.ventricular systolic dysfunction?
Atrial dilatation (seen clearly)
whereas constriction/shunts may be easily missed
What can increase or decrease l.ventricular ejection fraction?(2)
- physiological changes
2. disease
What is ejection fraction?
What is normal?
- Measurement (in percentage and amount) of how much blood is pushed out of l.ventricle with each contraction
What does ejection fraction also have links with other than blood volume?
Haemoglobin levels in blood (low EF can indicate anaemia)
What features of echo have an effect on how well l.ventricular ejection fraction is seen? (6)
- quality of images
- experience of operator
- calculation method (M-mode or Simpson’s bilane)
- Use of contrast agents
- time consuming to perform accurately
- normal range not routinely established for each patient which can influence interpretation
What is a normal l.ventricular ejection fraction in %?
50-80%
What is a mild l.ventricular ejection fraction in %?
40-50%
What is a moderate l.ventricular ejection fraction in %?
30-40%
What is a severe l.ventricular ejection fraction in %?
<30%
How is Biplane modified Simpson’s Rule used as an accurate measuring method for l.ventricular ejection fraction?
- divides l. ventricular cavity into multiple slices of known thickness and diameter
- volume of each slice= area x thickness
- thinner slices give a more accurate volume estimate
- endocardial border needs to be traced accurately
What is a MUGA scan? (Multigated acquisition)
- much easier to obtain accurate figure for l.ventricular ejection fraction
- greater reproducibility
- ionising radiation
- no additional structural information needed
- centre specific normal range
What 2 screening tests are used to find out l.ventricular ejection fraction?
- biplane modified Simpson’s rule
2. MUGA: multigated acquisition
What is Grade 1 Heart Failure?
- no limitation on exercise tolerance
- no symptoms during usual activity
What is Grade 2 heart failure?
- mild limitation on exercise tolerance
- comfortable with rest or with mild exertion
What is Grade 3 heart failure?
- moderate limitation on exercise tolerance
- comfortable only at rest
What is Grade 4 heart failure?
- severe limitation on exercise tolerance
- any physical activity brings on discomfort and symptoms occur at rest
Does heart failure= reduced cardiac output?
NO: heart failure isn’t equal in any way to reduced cardiac output and how much blood is ejected. This depends on how much blood body needs to skeletal muscle and vital organs. Capacity to increase cardiac output is different in heart failure patient. Very complex!
Why is heart failure a systemic disorder?
Affects many systems:
- cardiac dysfunction
- renal dysfunction
- skeletal muscle dysfunction
- systemic infammation
- neurohormonal activation (mostly maladaptive)
What effect does heart failure have on renin-angiotensin- aldosterone system?
- salt and water retention
- adverse haemodynamics
- l.ventricular hypertrophy/ remodelling and fibrosis
- hypokalaemia and hypomagnesaemia
What effect does heart failure have on the sympathetic nervous system?
- arrhythmogenic
- adverse haemodynamics
- increase in renin
- changes to electrolytes
Define cardiac failure.
Cardiac output is inadequate with the body’s requirements
Does high or low BP often lead to heart failure in most patients?
High BP (hypertension)
What pathologies when combined together can ultimately lead to hear failure and become symptomatic over time?
- coronary artery disease
- hypertension
- cardiomyopathy
- valvular disease
Which lead to ventricular injury
- pathogenic remodelling
- l.ventricular dysfunction
- neurohormonal activation occurs and symptoms presents leading to heart failure
What are the most common neurohormonal effects that lead to heart failure? (3)
- vasoconstriction
- endothelial dysfunction
- renal sodium retention
(all can increase BP)
What are the treatments for heart failure? (8)
- ACEIs
- Beta blockers
- aldosterone receptor blockers
- ARBs
- ARNIs: angiotensin receptor neprilysin inhibitor
- Sacubitril Valsartan (neprilysin inhibitor +ARB combined)
- Ivabradine
- Digoxin
