19. Investigation and Management of Heart Failure Flashcards
What is used to classify heart failure?
NYHA classification (New York Heart Association)
What is NYHA class I?
Asymptomatic, no limitation of physical activity
- ordinary physical activity does not cause undue fatigue, palpitation, dyspnoea or anginal pain
What is NYHA class II?
- Slight limitation of physical activity
- Ordinary physical activity results in symptoms (fatigue, palpitations, dyspnoea, angina)
- No symptoms at rest
What is NYHA class III?
- Marked limitation of physical activity
- Less than ordinary physical activity results in symptoms
- No symptoms at rest
What is NYHA class IIII?
- Inability to carry out any physical activity without symptoms
- May have symptoms at rest
- Discomfort increases with any degree of physical activity
What are the different types of heart failure?
- Left ventricular systolic dysfunction (HFrEF)
- Heart failure with a preserved ejection fraction (HFpEF)
- Valvular / structural (e.g. VSD) heart failure
- Right ventricular failure
- High output cardiac failure
List the key questions asked during an investigation into a suspected heart failure patient
- Does the patient have heart failure?
- History and clinical examination?
- Differential diagnosis? - What sort of heart failure does the patient
- Left ventricular systolic dysfunction
- Heart failure with a preserved ejection fraction
- Valvular / structural (e.g. VSD) heart failure
- Right ventricular failure
- High output cardiac failure - What is causing heart failure?
- Ischaemic heart disease? Hypertension? Viral?
What is ABCDE for heart failure?
Airway, Breathing, Circulation, Disability, Exposure
What is given for symptomatic treatment of heart failure?
Furosemide
How does furosemide work?
It is a loop diuretic:
- it inhibits the Na/K/CL transporter at the ascending loop of henle
Also has venodilatory effects
What is included in prognostic treatment of heart failure? LVSD only
– Cardiac rehabilitation / community heart failure team
– ACE/ARB
– Beta blocker
– MRA (spironolactone)
– Sacubitril valsartan
– ICD / Biventricular pacemaker
– (Ivabradine, hydralazine / nitrate, i.v. Iron, CABG)
What should be measured with IV furosemide use?
- HR, BP, RR, pO2%, CXR
- Fluid balance, hourly urine output
- Daily weights (aim for 1kg weight loss per day)
List 7 investigations for heart failure
- Full blood count
- Electrolytes and renal function
- Brain Natriuretic Peptide (BNP)
- ECG
- CXR
- Coronary angiography
- Echocardiogram
How can FBC used to investigate heart failure?
A FBC can be used to check for anaemia as the symptoms of anaemia are similar to heart failure.
As well as this anaemia (of chronic disease) is prevalent in those with heart failure and can worsen heart failure as it puts further strain on the heart to meet the body’s demands.
How can electrolytes and renal function be used to investigate heart failure?
Chronic kidney failure causes fluid overload as the kidney is unstable to properly remove fluid from the body.
Renal function deteriorates in heart failure.
Fluid overload can cause the symptoms of heart failure.
The measurement of Na/K levels can be beneficial when determining medication for patients.
How can brain natriuretic peptides (BNP)/ NTpro-BNP be used to investigate heart failure?
These peptides are hormones released in response to
atrial/ventricular stretch due to fluid overload.
It is produced to try and reduce BP by increasing sodium loss and therefore increasing water loss.
An elevated BNP suggests heart failure while a normal BNP with breathlessness usually excludes heart failure.
How does AF affect BNP levels?
Atrial fibrillation can triple BNP / NTpro-BNP
WHat are the effects of BNP?
↑ Natriuresis
↑ Diuresis
↑ vasodilation
↓ RAAS activity
What blood tests would be carried out?
Main:
• FBC
- Patients with heart failure are often anaemic
- Anaemia might explain symptoms
• U&Es
- Renal function often deteriorates in heart failure
- Na / K levels important for medications
• NTpro-BNP
Others: • LFTs - May be elevated due to hepatic congestion • Clotting - Important if considering anticoagulation • Thyroid function, vitamin D level - Alternative explanation for symptoms • CRP - Look for infection / inflamation
How can an ECG be used to investigate heart failure?
An ECG can be used to measure electrical activity in the heart.
An abnormal ECG with a raised BNP provides evidence for heart failure.
What are the features of heart failure in a CXR?
- Cardiomegaly
- Upper lobe diversion
- Fluid in the fissure
- Pleural effusions (bilateral blunting of the costofrenic angles)
- Kerley B lines (pulmonary oedema)
An enlarged heart can be seen on a chest x-ray as an increased cardiothoracic ratio (ratio of maximal horizontal cardiac diameter to maximal horizontal thoracic diameter on a chest X-ray). This can indicate left sided heart failure.
How can an echocardiogram be used to investigate heart failure?
This device can be used to measure the ejection fraction to help determine the type of heart failure.
It can also assess the valve and ventricular function to help determine the causative factor.
How can coronary angiography be used to investigate heart failure?
This technique allows for the imaging of coronary arteries and can then be used to determine if they’re blocked by an atherosclerotic plaque.
If there’s blockage of the coronary artery, it’ll cause a reduction in the delivery of oxygen to the myocardium. This outs a strain on the heart.
What are the key history questions?
- Recent viral illness
- Anabolic steroids
- Alcohol
- Smoking
- Family history
How can acute heart failure be treated?
Acute heart failure an be managed in hospital using the following methods:
- Deliver oxygen
- First line use of the IV loop diuretic, Furosemide
- Heparin to reduce the risk of venous clots forming or to prevent propagation of those that have already formed.
- Ventilator support if needed
- IV nitrates
How can chronic heart failure be treated?
- To treat chronic heart failure it’s very important to treat the original cause.
For example a heart transplant or a mechanical assist device (valve disorders). Pacemakers can be used for arrhythmias and implanted defibrillators can also be employed.
- Use of non-pharmacological management
Reduce salt intake, increase aerobic exercise, reduce alcohol intake - Pharmacological therapy
This is mainly for symptomatic improvement and can be used to delay the progression of heart failure
The aim of this form of therapy is to reduce the after-load and increase the cardiac output.
Give 5 examples of pharmacological treatments that can be used to treat chronic heart failure, describe their function
- ACE inhibitors
These prevent the action of the ACE enzymes in the conversion of angiotensin I to angiotensin II.
This prevents the formation of aldosterone and prevents vasoconstriction associated with angiotensin II. - Angiotensin receptor blockers
These block the activation of AT1 receptors preventing the activation of angiotensin II. - Beta- blockers
These are competitive antagonists that block adrenergic receptor sites meaning that noradrenaline and adrenaline can’t bind and activate.
They can be used to cause a reduction in blood pressure. - Spironolactone
It’s a loop diuretic and works to treat fluid retention and the build up of oedema. - Diuretics
Diuretics are drugs that cause diuresis which is an increased production of urine. This reduces the volume of blood in circulation.
How does Sacubitril valsartan work?
Augments the actions of BNP:
- vaslsartan is a angiotensin II receptor (type I) blocker (prevents vasodilation and aldosterone action)
- sacubitril inhibits enzyme that degrades ANP/BNP
What is the compensatory response in heart failure?
Early compensatory mechanism to improve CO:
- Increase cardiac contractility
- Arterial and venous vasoconstriction
- Tachycardia
- RAAS
Why is the compensatory response damaging?
- Vasocontriction and fluid retension by RAAS leads to increased wall stress leading to hypertrophy
- Increased wall stress and increases contractility and heart rate leads to increase in oxygen demand which cannot be met so contractility decreases
- Continuous sympathetic activation has direct cardiotoxic effects leading to myocyte damage
What is the long term effect of the compensatory response on β1-adrenergic receptors in the heart?
- β-adrenergic receptors are down-regulated / uncoupled
- Noradrenaline:
• Induces cardiac hypertrophy / myocyte apoptosis and necrosis via α receptors
• Induce up-regulation of the RAAS - Reduction in heart rate variability (reduced paraSNS and increased SNS)
What are the physiological effects of Beta Blockers?
- Reduce heart rate (cardiac beta receptor)
- Reduce BP (…..reduce cardiac output)
1+2 => Reduced myocardial oxygen demand - Reduce mobilisation of glycogen
- Negate unwanted effects of catecholamines
What is the main management for heart failure with preserved ejection fraction?
Control BP, limited evidence spironolactone
What is the management of HFrEF for NYHA I?
- risk factor reduction, patient and family education
- treat comorbidities (hypertension, diabetes, CAD, dyslipidaemia)
- Use ACEi or ARBs
What is the management of HFrEF for NYHA II-III?
- ACEi, ARBs, beta blockers, diuretics (if fluid overload)
- mineralcorticoid receptor antagonist
- cardiac rehabilitation
- evaluate iron deficiency
- cardiac re-synchronisation therapy and/or ICD
- Sacubitril valsartan
What is the management of HFrEF for NYHA III- IV?
- implantable monitoring device
- assess biomarkers, evaluate risk
What is the management of HFrEF for NYHA IV?
- palliative care
- transplant
- end of life discussions
