Acute Heart Failure
NICE guidelines [CG187] Acute heart failure: diagnosis and management. Last updated: Nov 2021.
Background Information
Definition
There are 2 main types of acute heart failure:
- De novo acute heart failure: sudden onset of heart failure in someone with no history or diagnosis of heart failure
- Acute decompensated chronic heart failure: acute worsening of symptoms in someone with established chronic heart failure
Aetiology
De Novo Acute Heart Failure
- Acute coronary syndrome – most common and important
- Acute valvular disease
- Acute myocarditis
- Arrhyhtmias
Acute Decompensated Chronic Heart Failure
- Acute infections (e.g. respiratory tract infection, UTI)
- Non-adherence with medication / dietary restrictions
- Atrial fibrillation and other arrhythmias
- Acute coronary syndrome
- Uncontrolled hypertension
- Anaemia
Complications
Main complications are:
- Haemodynamic instability (can cause cardiogenic shock)
- Pulmonary congestion
- End-organ hypoperfusion
Diagnosis
Clinical Features
Symptoms
Pulmonary and systemic congestion are the main presenting features:
- Pulmonary congestion (from left ventricular failure)
- Sudden onset dyspnoea and orthopnoea
- Cough +/- pink frothy sputum
- Systemic congestion (from right ventricular failure)
- Peripheral oedema
- Weight gain
Examination Findings
Pulmonary and systemic congestion are the main presenting features:
- Pulmonary congestion (from left ventricular failure)
- Bi-basal crackles
- Cardiac wheeze
- S3 gallop rhythm
- Systemic congestion (from right ventricular failure)
- Raised JVP
- Peripheral oedema
- Ascites
- Congestive hepatopathy
Investigation and Diagnosis
Diagnostic Tests
Initial diagnostic test: chest X-ray
- A combination of typical clinical features and chest X-ray findings is usually sufficient to diagnose acute heart failure and initiate treatment
Measure serum BNP or NT-proBNP level to rule out heart failure
- Heart failure is unlikely if: BNP < 100 ng/L or NT-proBNP < 300 ng/L
- Many other conditions (e.g. CKD, COPD, pulmonary embolism) would raise BNP / NT-proBNP; therefore it is only useful to rule out heart failure, but not to help diagnose heart failure
Confirmatory test: trans-thoracic echocardiogram
- If de novo acute heart failure → perform within 48 hours of admission
Typical chest X-ray findings in heart failure are (ABCDE):
- A: Alveolar oedema (perihilar bat wing opacities – from fluid accumulation in alveolar spaces)
- B: Kerley B lines (short horizontal lines at peripheral lung margins – from interstitial oedema)
- C: Cardiomegaly (>50% of thoracic width) (NB heart size can ONLY be assessed in a PA chest X-ray)
- D: Dilated upper lobe vessels (↑ left atrial pressure → redistribution of blood to upper lobes)
- E: Pleural effusion (typically bilateral transudative effusion)
Work Up
A standard heart failure workup includes:
- Chest X-ray
- ECG
- Blood tests (FBC, LFT, U&E, TFT, lipid profile, HbA1c)
- Urinalysis
- Peak flow or spirometry
Management
Initial Management
1st line: IV loop diuretic (furosemide 40-120mg / bumetanide 1-3mg) – to relieve congestive symptoms
Add-on therapy:
- IV nitrates if there is:
- Concomitant myocardial ischaemia, or
- Severe hypertension, or
- Aortic or mitral regurgitation
- Ventilatory support
- CPAP can be used in severe cardiogenic pulmonary oedema
- Endotracheal intubation and mechanical ventilation – last resort
- If cardiogenic shock → consider inotropes (e.g. dobutamine) or vasopressors (e.g. noradrenaline, adrenaline)
Do not routinely discontinue long-term heart failure medications, unless there are clear contraindications:
- Beta blocker should be stopped if HR <50 bpm / shock / 2nd or 3rd degree AV block
- ACE inhibitors should only be stopped if there is AKI / shock