Introduction
Acute heart failure (AHF) is life-threatening emergency. AHF is a term used to describe the sudden onset or worsening of the symptoms of heart failure. Thus it may present with or without a background history of pre-existing heart failure. AHF without a past history of heart failure is called de-novo AHF. Decompensated AHF is more common (66-75%) and presents with a background history of HF.
Epidemiology
- Incidence: 200.00 cases per 100,000 person-years
- Peak incidence: 70+ years
- Sex ratio: 1:1
| Condition | Relative incidence |
|---|---|
| Acute exacerbation of COPD | 3.75 |
| Acute heart failure | 1 |
| <1 | 1-5 | 6+ | 16+ | 30+ | 40+ | 50+ | 60+ | 70+ | 80+ |
Aetiology
AHF is usually caused by a reduced cardiac output that results from a functional or structural abnormality.
De-novo heart failure is caused by and increased cardiac filling pressures and myocardial dysfunction usually as a result of ischaemia. This causes reduced cardiac output and therefore hypoperfusion. This, in turn can cause pulmonary oedema. Other less common causes of de-novo AHF are:
Decompensated heart failure accounts for most cases of AHF. The most common precipitating causes of acute AHF are:
There is generally a history of pre-existing cardiomyopathy. It usually presents with signs of fluid congestion, weight gain, orthopnoea and breathlessness.
De-novo heart failure is caused by and increased cardiac filling pressures and myocardial dysfunction usually as a result of ischaemia. This causes reduced cardiac output and therefore hypoperfusion. This, in turn can cause pulmonary oedema. Other less common causes of de-novo AHF are:
- Viral myopathy
- Toxins
- Valve dysfunction
Decompensated heart failure accounts for most cases of AHF. The most common precipitating causes of acute AHF are:
- Acute coronary syndrome
- Hypertensive crisis: e.g. bilateral renal artery stenosis
- Acute arrhythmia
- Valvular disease
There is generally a history of pre-existing cardiomyopathy. It usually presents with signs of fluid congestion, weight gain, orthopnoea and breathlessness.
Clinical features
Generally speaking, the signs and symptoms of AHF are as follows:
Sometimes the presentation will be that of the underlying cause (e.g: chest pain, viral infection)
Over 90% of patients with AHF have a normal or increased blood pressure (mmHg).
| Symptoms | Signs |
| Breathlessness | Cyanosis |
| Reduced exercise tolerance | Tachycardia |
| Oedema | Elevated jugular venous pressure |
| Faitgue | Displaced apex beat |
| Chest signs: classically bibasal crackles but may also cause a wheeze | |
| S3-heart sound |
Sometimes the presentation will be that of the underlying cause (e.g: chest pain, viral infection)
Over 90% of patients with AHF have a normal or increased blood pressure (mmHg).
Investigations
The diagnostic workup for patients with AHF includes:
- Blood tests – this is to look for any underlying abnormality such as anaemia, abnormal electrolytes or infection.
- Chest X-ray – findings include pulmonary venous congestion, interstitial oedema and cardiomegaly
- Echocardiogram – this will identify pericardial effusion and cardiac tamponade
- B-type natriuretic peptide – raised levels (>100mg/litre) indicate myocardial damage and are supportive of the diagnosis.
Management
Management options in acute heart failure include:
Consideration should be given to discontinuing beta-blockers in the short-term.
- oxygen
- diuretics
- opiates
- vasodilators
- inotropic agents
- CPAP
- ultrafiltration
- mechanical circulatory assistance: e.g. intra-aortic balloon counterpulsation or ventricular assist devices
Consideration should be given to discontinuing beta-blockers in the short-term.