Acute Heart Failure
Rapid onset or worsening of heart failure symptoms requiring urgent medical intervention. May present as de novo acute HF or acute decompensation of chronic HF.
Key Facts
- Presentation: acute dyspnoea, orthopnoea, pink frothy sputum, bilateral crepitations, elevated JVP
- Immediate management: sit upright, IV furosemide 40-80mg, oxygen if SpO₂ <94%, GTN infusion if SBP >90 mmHg
- Do NOT give morphine routinely (NICE NG106) - associated with increased mortality in acute HF
- NT-proBNP: aids diagnosis; >300 pg/mL supportive (with clinical context)
- CPAP/NIV: consider if respiratory distress persists despite initial treatment (3CPO trial)
- Cardiogenic shock: inotropes (dobutamine 2.5-10mcg/kg/min), consider IABP/Impella
- In-hospital mortality: ~5-10%; 1-year mortality post-discharge: ~25-30%
- Before discharge: ensure optimisation of HF medications; arrange follow-up within 2 weeks
Overview
Key Facts
Acute heart failure (AHF) is the rapid onset or worsening of signs and symptoms of heart failure. It may present as a first episode (de novo) or more commonly as an acute decompensation of chronic heart failure (ADCHF). It is a medical emergency requiring urgent assessment and treatment.
Epidemiology
- ~80,000 admissions per year in England
- Accounts for ~5% of all emergency medical admissions
- Mean age at presentation: ~75 years
- In-hospital mortality: ~5-10%
- 30-day readmission rate: ~25%
- 1-year mortality post-discharge: ~25-30%
Aetiology
Precipitants of acute decompensation:
- Acute coronary syndrome
- Arrhythmia (especially new-onset AF with rapid ventricular rate)
- Medication non-adherence or dietary indiscretion
- Infection/sepsis
- Uncontrolled hypertension
- Acute valvular dysfunction (MR, AR)
- Pulmonary embolism
- Renal failure
- Anaemia
- Thyrotoxicosis
Pathophysiology
- Acute increase in LV filling pressures → pulmonary congestion → pulmonary oedema
- Neurohormonal activation (RAAS, SNS) causes vasoconstriction and fluid retention
- Forward failure: reduced cardiac output → hypoperfusion
- Backward failure: elevated filling pressures → congestion
- Acute pulmonary oedema: fluid transudation into alveoli impairs gas exchange
Clinical Presentation
Acute Pulmonary Oedema
- Severe dyspnoea, orthopnoea, paroxysmal nocturnal dyspnoea
- Pink frothy sputum
- Bilateral fine crepitations
- Tachypnoea, tachycardia
- Elevated JVP
- Third heart sound (S3)
- Hypoxia
Cardiogenic Shock
- Hypotension (SBP <90 mmHg)
- Cold, clammy peripheries
- Oliguria (<0.5 mL/kg/h)
- Confusion, altered consciousness
- Elevated lactate
Right Heart Failure Predominant
- Peripheral oedema
- Elevated JVP
- Hepatomegaly, ascites
- Right-sided pleural effusion
Red Flags
- SBP <90 mmHg (cardiogenic shock)
- SpO₂ <90% despite high-flow oxygen
- Respiratory rate >25/min
- Altered consciousness
- Concurrent acute MI
Differential Diagnosis
| Diagnosis | Key Features | Investigation |
|---|---|---|
| Acute exacerbation of COPD | Smoking history, wheeze, hyperinflation | Spirometry, CXR, ABG |
| Pneumonia | Fever, productive cough, consolidation on CXR | CXR, blood cultures, CRP |
| Pulmonary embolism | Pleuritic pain, DVT risk factors, acute RV strain | CTPA, D-dimer |
| ARDS | Bilateral infiltrates, risk factor (sepsis, trauma), PaO₂/FiO₂ <300 | Berlin criteria |
| Acute asthma | Wheeze, atopy history, PEFR reduced | PEFR, CXR |
| Cardiac tamponade | Beck triad (hypotension, muffled HS, elevated JVP), pulsus paradoxus | Echo |
| Nephrotic syndrome | Heavy proteinuria, hypoalbuminaemia | ACR, albumin |
Diagnosis / Investigation
Bedside
- ECG: ischaemia, arrhythmia, LVH
- Observations: HR, BP, SpO₂, RR, urine output
- ABG: hypoxia, type 1 respiratory failure, metabolic acidosis (if shock)
Bloods
- NT-proBNP (or BNP): >300 pg/mL supportive; also prognostic
- Troponin: exclude ACS as precipitant
- U&Es: renal function, electrolytes
- FBC: anaemia, infection
- LFTs: hepatic congestion
- CRP: infection screen
- Lactate: tissue perfusion
- TFTs: thyroid dysfunction
Imaging
- Chest X-ray: upper lobe venous distension, bilateral alveolar shadowing, Kerley B lines, cardiomegaly, pleural effusions
- Echocardiography: urgent - assess LV/RV function, valvular abnormalities, pericardial effusion
- Lung ultrasound: B-lines (interstitial oedema) - increasingly used at bedside
Special Tests
- Coronary angiography: if ACS precipitant
- Pulmonary artery catheterisation: in refractory shock (rarely needed)
Management
Non-pharmacological
- Sit patient upright (reduces venous return and work of breathing)
- High-flow oxygen if SpO₂ <94%
- Continuous monitoring: ECG, SpO₂, BP, urine output
- Fluid restriction: 1.5L/day
- Daily weights
Pharmacological
Acute management (wet and warm - congested, adequate perfusion):
- IV furosemide 40-80mg bolus (or double usual oral dose if already on furosemide); repeat/increase as needed
- If poor response: furosemide infusion 5-40mg/hour or add metolazone 2.5-10mg OD (sequential nephron blockade)
- GTN infusion 1-10mg/hour: if SBP >90 mmHg (reduces preload and afterload)
- Do NOT routinely give morphine (NICE NG106 - increased ICU admission and mortality)
- CPAP/BiPAP: if persistent respiratory distress despite initial treatment (improves oxygenation and work of breathing)
Cardiogenic shock (wet and cold):
- Dobutamine 2.5-10 mcg/kg/min (inotrope)
- Noradrenaline if significant hypotension (vasopressor)
- Milrinone: phosphodiesterase inhibitor (inodilator)
- Levosimendan: calcium sensitiser (limited UK availability)
- Consider mechanical circulatory support: IABP, Impella, VA-ECMO
Before discharge:
- Initiate/optimise HFrEF quadruple therapy before discharge where possible
- SGLT2 inhibitor can be started in hospital (EMPULSE trial)
- Arrange specialist heart failure follow-up within 2 weeks of discharge
- Cardiac rehabilitation referral
- Medication reconciliation and patient education
Surgical/Interventional
- PCI/CABG if ACS precipitant
- Valve surgery/intervention if acute valvular cause
- Mechanical circulatory support for refractory cardiogenic shock
- Ultrafiltration for diuretic-resistant fluid overload
Referral Criteria
- All patients: specialist heart failure team review during admission
- Cardiogenic shock: intensive care and/or advanced HF centre
- Refractory to medical therapy: consider transplant assessment
Prognosis
- In-hospital mortality: ~5-10%
- 30-day mortality: ~10-15%
- 1-year mortality post-discharge: ~25-30%
- 30-day readmission rate: ~25%
- Prognosis worse with: cardiogenic shock, ACS trigger, low SBP at admission, high BNP, renal dysfunction
- De novo AHF generally has better prognosis than ADCHF
- Each hospitalisation for HF is associated with progressive decline and worsened outcomes
Other Relevant Information
Clinical Profiles in Acute Heart Failure
| Profile | Congestion | Perfusion | Management |
|---|---|---|---|
| Warm and wet | Yes | Adequate | Diuretics ± vasodilators |
| Cold and wet | Yes | Poor | Inotropes + diuretics |
| Cold and dry | No | Poor | Fluids cautiously ± inotropes |
| Warm and dry | No | Adequate | Adjust oral therapy |
CXR Signs of Heart Failure (ABCDE)
| Letter | Feature |
|---|---|
| A | Alveolar oedema (bat-wing shadowing) |
| B | Kerley B lines (interstitial oedema) |
| C | Cardiomegaly (CTR >50%) |
| D | Diversion of blood to upper lobes |
| E | Effusion (pleural) |