Heart Failure Flashcards
What is the pathophysiological definition of chronic heart failure?
- syndrome in which despite normal or raised filling pressures, the heart is unable to maintain an adequate circulation to meet the requirements of normal metabolism
- excludes causes such as haemarrohage and dehydration - result in decreased CO but not caused by abnormality of cardiac function
What is the clinical definition of heart failure?
A clinical syndrome which is caused by an abnormality of hte heart, and characterised by a recognisable pattern of haemodynamic, renal, neural and hormonal responses
What are the 2 CARDINAL SYMPTOMS of heart failure?
Breathlessness and fatigue
What are 4 symptoms of LEFT heart failure?
- Dyspnoea
- Cough - may be worse at night, pink/frothy sputum
- Orthopnoea
- PND: paroxysmal nocturnal dyspnoea
- Fatigue
What are 5 SIGNS of left heart failure?
- Tachycardia
- Crepitations in lung bases - bibasal crackles
- Cardiac wheeze
- Weight loss: cardiac cachexia
- Gallop rhythm
What are 4 symptoms of RIGHT heart failure?
- Ankle swelling
- Fatigue
- Dyspnoea
- Right upper quadrant discomfort
What are 3 signs of right heart failure?
- Elevated JVP
- Oedema/ascites
- Hepatomegaly - sometimes
What are 4 key investigations for chronic heart failure?
- ECG
- CXR
- Echocardiagram - to define nature of cardiac abnormality
- Plasma BNP (B-type natriuretic peptide) - if normal can EXCLUDE diagnosis of heart failure
What causes the increase in B-type natriuretic peptide (BNP) in chronic heart failure?
Peptide released from venricle in response to ventricular stretch
Why is chronic heart failure becoming more common?
More patients now surviving MI: causes left ventricular damage, results in clinical syndrome of heart failure
What are 2 methods to classify causes of heart failure?
-
Physiological classification
- diastolic (impaired cardiac filling) vs systolic
- preload vs afterload
-
Anatomical classification
- Pericardial
- myocaridal
- endocardial
What is are 2 causes of the pericardial form of heart failure?
- Caused by pericardial effusion and tamponade; the high pressure prevents right ventricular filling, resulting in low cardiac output
- Pericardial constriction: syndrome in which a previously inflamed pericardium contracts and fibroses around the heart, preventing cardiac filling
What is the most common anatomical type of chronic heart failure?
Myocardial
What are 6 cases of myocardial heart failure?
- Coronary artery disease - 80% of all
- Hypertension
- Dilated cardiomyopathy
- Hypertrophic cardiomyopathy
- Myocarditis
- ‘Heart muscle diseases’ - infiltrative, endocrine, metabolic, neuromuscular, drugs and toxins
What are 5 types of ‘heart muscle diseases’ which can cause myocardial heart failure?
- Infiltrative: sarcoid, myeloid
- Endocrine: diabetes, hyperthryoidism, acromegaly
- Metabolic: haemochromatosis, due to iron overload
- Neuromuscular: drugs and toxins - alcohol, cytotoxics
- Drugs and toxins: alcohol, cytotoxics
What is the commonest cause of myocardial heart failure
Coronary artery disease - 80% of all
How does coronary artery disease lead to heart failure?
In most cases there is a history of myocardial infarction or angina
In some, disease can be silent and can only be diagnosed with appropriate investigation
What are 3 investigations required in suspected heart failure caused by coronary artery disease? What do they show?
- Echocardiography: regional wall-motion abnormalities of left ventricular function
- Cardiac MR scanning: can show areas of infarction
- Cardiac angriography - often required
What is the second most common cause of myocardiac heart failure, after coronary artery disease?
Hypertension
What are 3 causes of endocardial heart failure?
- valvular disease: aortic stenosis most common form in UK due to ageing population
- endocardial fibrosis (eosinophilic)
- Congenital lesions: ASD, VSD
Which of the two cardiac MRIs shows a normal heart and what is the difference?
Left is normal; right shows patient with left ventricular damage due to previous MI: left ventricle dilated, assuming spherical (abnormal) shape
How does diastolic dysfunction (40% of cases) cause heart failure?
Stiff ventricles results in inadequate filling. May be due to age, and cardiac response to increasing arterial stiffness with increasing age
What is the prognosis of heart failure?
Very poor - 5-10% annual mortality, likely to result in death of patient within a few years
Why is prognosis likely to be so poor in heart failure?
- Compensatory neural and hormonal responses in are deleterious in the long term. Leads to positive feedback and a vicious circle
Explain why compensatory mechanisms in heart failure lead to a vicious cycle, responsible for its poor prognosis.
- cardiac lesion leads to decreased cardiac output →
- leads to compensatory mechanisms in the sympathetic nervous system (autonomic) and RAAS
- these can cause further myocardial damage and ventricular dilatation (Laplace’s law), i.e. adverse loading
- damage to ventricle results in left ventricular remodelling
- kidney - abnormalities occur in response
- peripheral vessels - abnormalities occur in response
What is meant by adverse ventricular remodelling in heart failure?
- Even a small heart attack resulting in an area of infarction around the apex tends to result in progressive left ventricular dilatation and thinning
- shape changes from ellipse to sphere
- dilatation results in mechanically inefficient structure
What is the aim of treatment of heart failure?
Palliative: aim to improve symptoms and life expectancy, but don’t restore pumping capacity of heart
Options are aimed at treating the kidney and peripheral vasculature
What are 9 aspects of treatment of heart failure?
- Lifestyle measures
- Treat correctible causes
- ACE inhibitors
- beta blockers
- Diuretics
- Inotropes
- Spironolactone
- Implanted cardioversion defibrillators (ICD)
- Biventricular pacing
What are 5 lifestyle/simple measures to tackle heart failure?
- Fluid restriction: 1.5L per day
- No added salt to avoid fluid retention due to sodium retention
- Exercise
- Compliance with medication
- Stop ‘bad drugs’ e.g. NSAIDs which act on renal prostaglandin metabolism - need to preserve renal function
What can the use of NSAIDs in heart failure result in?
- Act on renal prostaglandin metabolism
- Can result in renal failure and fluid retention - big problems in heart failure
What are 5 correctible causes of heart failure that can be treated?
- Hypertension - give anti-hypertensives
- Drain pericardial fluid - for pericardial effusion/tamponase
- Remove pericardium - see above
- Valve replacement - for valvular endocardium cause
- CABG - coronary artery bypass graft - for myocardial disease due to coronary artery disease
What is the first line treatment for all patients with heart failure?
BOTH an ACE-inhibitor and a beta-blocker
How should an ACE-inhibitor and beta blocker be started to treat chronic heart failure?
Generally, one drug should be started at a time; NICE advice that clinical judgement should be used when determining which to start first
What are 3 beta blockers licensed to treat heart failure in the UK?
Bisoprolol, carvedilol, nebivolol
When do ACE-inhibitors and beta-blockers have no effect on mortality in heart failure?
In heart failure with preserved ejection fraction
What is second line treatment for chronic heart failure?
Aldosterone antagonist e.g. spironolactone, eplerenone (aka mineralocorticoid receptor antagonists)
What should be monitored when treating chronic heart failure with aldosterone antagonists and ACEis and why?
Both cause hyperkalaemia so monitor potassium
What are 5 third line treatment for chronic heart failure (after 1st line: ACEi and beta blocker and 2nd line: aldosterone antagonist)?
- Ivabradine
- Sacubitril-valsartan
- Digoxin
- Hydralazine in combination with nitrate
- Cardiac resynchronisation therapy
What is important to note about all the third line treatment options for chronic heart failure?
All can be initiated by a specialist only
What 2 types of treatment for heart failure produces no benefit in reducing mortality in the long term? What role do they play instead?
- Loop diuretics e.g. furosemide - managing fluid overload
- Digoxin: inotropic qualities treat symptoms
What are the 2 criteria for starting third line chronic heart failure treatment with ivabradine?
- Sinus rhythm >75/min
- Left ventricular fraction <35%
What are 2 key criteria for starting sacubitril valsartan as a third line treatment for chronic heart failure?
- Left ventricular fraction <35%
- Considerd on patient with reduced ejection fraction who are symptomatic on ACE inhibitors or ARBs
- should be initiated following ACEi or ARB washout period
Does digoxin reduce mrtality in patients with heart failure? What effect does it have?
No; may improve symptoms due to intotropic properties
When is digoxin strongly indicated to treat heart failure?
If there is coexistent atrial fibrillation
In which patients may hydralazine in combination with nitrate be particularly indicated to treat heart failure?
In Afro-Caribbean pateints
What is one of the key indications for cardiac resynchronisation therapy to treat chronic heart failure?
Widened QRS (e.g. left bundle branch block) complex on ECG
What 2 vaccinations should be offered to patients with chronic heart failure?
- annual influenza vaccine
- one off pneumococcal vaccine (usually just one bust booster every 5 years if CKD, asplenia or splenic dysfunction)
What is the first line investigation for chronic heart failure?
N-terminal pro-B-type natriuretic peptide (BNP) blood test
What are 2 potential actions to take based on the results of the BNP blood test for heart failure?
- If levels high: arrange specialist assessment including transthoracic echocardiography within 2 weeks
- If ‘raised’ arrange specialist assessment includign transthoracic echo within 6 weeks
What are 11 other factors that can increase BNP levels?
- Left ventricular hypertrophy/ dysfunction of many types
- Ischaemia
- Tachycardia
- Right ventricular overload
- Hypoxaemia (including pulmonary embolism)
- GFR<60ml/min - seen commonly in CKD
- Sepsis
- COPD
- Diabetes
- Age >70
- Liver cirrhosis
What are 6 factors that can decrease BNP levels?
- Obesity
- Diuretics
- ACE inhibitors
- Beta blockers
- Angiotensin 2 receptor blockers
- Aldosterone antagonists e.g. spironolactone
What are 3 natural effects of BNP?
- Vasodilator
- Diuretic and natriuretic
- Suppresses both sympathetic tone and the renin-angiotensin-aldosterone system
What is an extremely useful marker for prognosis in chronic heart failure?
BNP - higher, suggests poor prognosis
What should you aim for when dosing diuretics in chronic heart failure and why?
Aim for minimum dose possible and excessive dose causes a reduction in circulating volume; this lowers blood pressure, results in further activation of the sympathetic nervous system and RAAS which further damages heart vasculature and kidneys
What is the mechanism of action for ACEi to treat chronic heart failure?
inhibit the compensatory activation of the RAAS; reduce levels of circulating angiotensin II and aldosterone, both of which cause adverse effects on the myocardium, peripheral vasculature and kidneys
Reduce preload and afterload
What are 2 major side effects of ACEi?
- Renal dysfunction - MONITOR renal function during first few weeks then intervals
- Persistent dry cough
How should prescribed beta blockers be started in chronic heart failure?
Start at low dose and increase gradually - may feel worse at first
Wise to introduce in conjunction with cardiologist in secondary care and heart failure nursing team - can visit patient at home, supervise
What should you warn patients about when starting beta blockers to treat chronic heart failure?
Transient deterioration: may feel worse before gaining benefit due to negative inotropic effects
What are 2 important side effects of spironolactone?
- Renal dysfunction
- Hyperkalaemia - regular monitoring
What can be used to perform resynchronisation therapy in chonic heart failure?
Biventricular pacemaker - leads in L and R ventricle, works by ‘resynchronisation’ of LV contraction
What might be a way of identifying patients suitable for resynchronisation therapy to treat chronic heart failure?
Those with a wide QRS complex
What are 3 benefits of biventricular pacing to perform resynchronisation therapy in chronic heart failure?
- Improvement in exerise tolerance and quality of life
- Improvements in ejection fraction and reduced hospitalisation
- In appropriate patients, can reduce mortality
What are 3 complications/ risks associated with chronic cardiac failure?
- Left ventricular thrombus/ thromboembolic events
- Frequent cardiac arrhythmias
- Sudden cardiac death
What could be a future treatment for chronic heart failure?
Stem cells implantable mechanical pumps to restore pump function (or transplant/ revascularisation)
What could be the future for implanted cardioversion defibrillators in chronic heart failure?
Could reduce mortality from pump failure and ventricular arrhythmias in CHF; not yet recommended for routine use
Could be used for patients who have had extensive MI - should be assessed by cardiologist
What is heart failure with preserved vs reduced ejection fraction and what is the difference?
- Preserved: HFpEF: aka diastolic heart failure. heart muscle contracts normally but ventricles don’t relax during ventricular filling
- Reduced: HFrEF: aka systolic heart failure. heart muscle does not contract effectively, less oxygenised blood pumped around body
What is the classification used for heart failure?
New York Heart Association (NYHA) classification
What is NYHA class I?
- no symptoms
- no limitation: ordinary physical exercise does not cause undue fatigue, dyspnoea or palpitations
What is NYHA Class II?
- mild symptoms
- slight limitation of physical activity: comfortable at rest but ordinary activity results in fatigue, palpitations or dyspnoea
What NYHA class III?
- moderate symptoms
- marked limitation of physical activity: comfortable at rest but less than ordinary activity results in symptoms
What is NYHA class IV?
- severe symptoms
- unable to carry out any physical activity without discomfort: symptoms of heart failure are present even at rest with increased discomfort with any physical activity
What is acute heart failure?
Life threatening emergency: used to describe the sudden onset or worsening of the symptoms of heart failure - may present with or without past history of heart failure
What is the term used to describe acute heart failure (AHF) without a past history of heart failure?
De-novo AHF
What is decompensated AHF?
Presents with a background history of AHF, unlike de-novo AHF; sudden worsening of the signs and symptoms
What form of acute heart failure is more common?
Decompensated (66-75%) is more common than de-novo AHF
Within what age group does AHF usually present?
After age of 65; major cause for unplanned hospital admission in these patients
What is de-novo heart failure most commonly caused by?
Increased cardiac filling pressure and myocardial dysfunction, usually as a result of ischaemia
In addition to ischaemia, what are 3 further causes of de-novo heart failure?
- Viral myopathy
- Toxins
- Valve dyfunction
What are 4 common precipitating causes of decompensated AHF?
- Acute coronary sydrome
- Hypertensive crisis
- Acute arrhythmia
- Valvular disease
What is there often a pre-existing history of in decompensated heart failure?
pre-existing cardiomyopathy
What are 4 categories that patients with acute heart failure are broadly characterised as? (aside from NYHA)
- with or without hypoperfusion
- with or withou fluid congestion
What are 4 symptoms of acute heart failure?
- Breathlessness
- Reduced exercise tolerance
- Oedema
- Fatigue
What are 6 signs of acute heart failure?
- cyanosis
- tachycardia
- elevated JVP
- displaced apex beat
- chest signs: bibasal crackles, wheeze
- S3 heart sound
How might acute heart failure sometimes present, if not with the usual signs and symptoms?
The underlying cause e.g. chest pain, viral infection
What will blood pressure generally be like in acute heart failure?
over 90% of patients: normal or increased
What are 4 inestigations for patients with acute heart failure, to diagnose the condition?
- Blood tests - to look for underlying abnormality such as anaemia, abnormal electrolytes or infection
- Chest X-ray - findings include pulmonary venous congestion, interstitial oedema and cardiomegaly
- Echocardiogram: to identify pericardial effusion and cardiac tamponade
- BNP - if raised, indicates myocardial damage, supports diagnosis
What are 3 potential findings on the chest x-ray in acute heart failure?
- pulmonary venous congestion
- interstitial oedema
- cardiomegaly
What are 2 things that can be identified using echo in acute heart failure?
- Pericardial effusion
- Cardiac tamponade
What are 8 management options in acute heart failure?
- Oxygen
- IV loop diuretics
- Opiates
- Vasodilators
- Inotropic agents
- CPAP
- Ultrafiltration
- Mechanical circulatory assistance: e.g. intra-aortic balloon counterpulsation or ventricular assist devices
