Overview
Acute heart failure is either new-onset heart failure in people without a history of cardiac dysfunction, or an acute decompensation (worsening) of chronic heart failure. Acute heart failure should be suspected in any patient with a sudden onset of breathlessness, ankle swelling, fatigue, and reduced exercise tolerance.
During acute heart failure, patients have volume overload with pulmonary and/or systemic oedema (congestion). This gives rise to the signs and symptoms seen.
It may be helpful to read Heart Failure: An Overview to help with remembering and making sense of this chapter.
Epidemiology
- Acute heart failure makes up around 5% of all adult emergency hospital admissions
- Mean age of onset is 78 years
- Affects men more in all ages except 85 years or older, where women predominate
Causes
- Acute coronary syndrome
- Hypertensive emergencies
- Arrhythmia
- Chest trauma
- Pulmonary embolism
- Infection e.g. myocarditis
- Cardiac tamponade
- Myocarditis
- Causes of high-output heart failure (e.g. anaemia, sepsis, thyrotoxicosis)
Risk Factors
- History of heart failure
- History of cardiovascular disease
- Hypertension
- Older age
- Diabetes mellitus
- Family history of cardiovascular disease
- Family history of cardiomyopathy
- Excess alcohol consumption
- Smoking
- History of arrhythmia
- History of sarcoidosis or haemochromatosis
- History of chemotherapy
- Some drugs NSAIDs, corticosteroids, rate-limiting calcium channel blockers (diltiazem or verapamil)
- Valvular heart disease
Presentation
The two main features of acute heart failure are breathlessness and ankle swelling. Features of pulmonary oedema are predominant and most urgent:
- Breathlessness
- Orthopnoea
- Paroxysmal nocturnal dyspnoea
- Fatigue
- Tachycardia
- Tachypnoea
- S3 heart sound
- Crackles and wheezes on auscultation
- Hypotension – if cardiogenic shock occurs, most patients have normal or high blood pressures
- Cyanosis
Other features include:
- Elevated jugular venous pressure
- Displaced apex beat
- Peripheral oedema
- Cough productive of frothy white/pink sputum
Investigations
In general, investigations should be taken at the same time as starting management of acute heart failure, as it is a medical emergency.
If haemodynamically unstable/respiratory failure
- Immediate ECG:
- May show arrhythmia or changes in wave morphology and/or duration
- Immediate bedside echocardiography:
- Shows ventricular dysfunction and may identify the underlying cause
If haemodynamically stable
- ECG:
- May show arrhythmia or changes in wave morphology and/or duration
- Chest x-ray – may show:
- Pulmonary congestion
- Pulmonary oedema
- Pleural effusion
- Cardiomegaly
- Blood tests:
- NT-proBNP blood test
- Elevated
- Troponin:
- May be elevated
- Full blood count:
- May identify anaemia
- May identify leukocytosis suggesting infection
- Urea and electrolytes (U&Es):
- As a baseline and may identify renal failure
- Liver function tests (LFTs):
- To screen for liver pathology which can worsen heart failure or to screen for liver pathology due to heart failure
- Thyroid function tests (TFTs):
- To screen for hypo- or hyperthyroidism
- C-reactive protein:
- Non-specific marker of inflammation, may be elevated
- D-dimer:
- If pulmonary embolism suspected
- NT-proBNP blood test
- Echocardiography:
- This assesses the systolic and diastolic function of the ventricles
Management
All patients
If the patient is already taking regular medications for heart failure, these should be continued. Beta-blockers should only be stopped if any of the following apply:
- The patient’s heart rate is <50 bpm
- The patient has a 2nd/3rd-degree heart block
- The patient is in cardiogenic shock
Further management of acute heart failure depends on if the patient is haemodynamically stable or not.
Haemodynamically stable
- Treat underlying cause
- Sit the patient up
- IV loop diuretic if there are signs and symptoms of congestion e.g. furosemide
- If concomitant myocardial ischaemia, aortic/mitral regurgitation: vasodilators e.g. IV GTN/isosorbide dinitrate
- Vasodilators can cause hypotension, so they’re used with caution or avoided
- They are not routinely given to people with acute heart failure
- If loop diuretic is insufficient and there are still signs and symptoms of congestion, consider an aldosterone antagonist e.g. spironolactone or eplerenone
- Oxygen only if saturations are <90%
- Consider CPAP if respiratory failure occurs (severe dyspnoea with or without acidaemia)
- Consider invasive ventilation if respiratory failure occurs or there is reduced consciousness/physical exhaustion
Haemodynamically unstable or in shock
- Identify and treat the underlying cause
- Request critical care
- Vasoactive drugs – given in a specialist setting:
- Inotropes (e.g. dobutamine):
- If there is severe left ventricular dysfunction with potentially reversible cardiogenic shock
- Vasopressors (e.g. noradrenaline):
- Generally used if there is an insufficient response to inotropes and evidence of end-organ hypoperfusion
- Inotropes (e.g. dobutamine):
- Oxygen only if saturations are <90%
- Consider CPAP if respiratory failure occurs (severe dyspnoea with or without acidaemia)
- Consider invasive ventilation if respiratory failure occurs or there is reduced consciousness/physical exhaustion
Monitoring
- During diuretic therapy, U&Es, weight, and urine output should be closely monitored
- After discharge, follow-up from the specialist heart failure time should take place within 2 weeks
- Once patients have stable heart failure, they should be encouraged to have regular exercise and be enrolled in a multidisciplinary care management programme
Patient Advice
- Patients should take measures to prevent further episodes:
- Restricting fluid and salt intake
- Reducing alcohol intake
- Continuing medication as prescribed
- Regularly checking weight
- Patients should be safety-netted on when to seek medical help
Complications
- Arrhythmia due to acute heart failure itself or inotropes
- Hypotension due to IV nitrates
- Acute kidney injury due to diuretics
- Electrolyte imbalances due to diuretics
- Worsening myocardial ischaemia due to inotropes
Prognosis
- The mortality rate of acute heart failure is around 11%
- Factors associated with a worse prognosis are older age, male sex, ischaemic heart disease, previous heart failure, hypotension, renal dysfunction, anaemia, elevated troponin, elevated NT-proBNP, and other comorbidities (e.g. cancer)