The signs and symptoms of heart failure are common and notoriously non-specific (table 1). Some 10–20% of patients who are admitted via the emergency department who are eventually diagnosed as having acute heart failure may have initial treatment for an alternative diagnosis, for example chronic obstructive airway disease.1,2
Misdiagnosis and underdiagnosis are also common in the community; as many as 16% of patients over the age of 65 presenting with breathlessness to their general practitioner (GP) may have undiagnosed heart failure as the cause.3 The prevalence of systolic dysfunction (left ventricular ejection fraction [LVEF] <50%) in patients over 45 years of age may be as high as 6%; much higher than the current estimated heart failure prevalence of 1-2% in the UK.4
The heart failure syndrome is a broad spectrum ranging from those presenting in extremis to the emergency department to patients presenting to their GPs with symptoms for many months.
Acute heart failure generally refers to patients presenting as emergencies to hospital, usually with either pulmonary oedema or with gross fluid retention. Such patients are often presenting for the first time, but may be patients having an exacerbation of their previously stable heart failure; sometimes described as ‘decompensated’ heart failure. They have acutely abnormal haemodynamics.
In contrast, most patients with chronic heart failure have been treated medically and will usually have few, if any, symptoms or signs at rest. The term ‘congestive’ heart failure, often used to describe patients in this condition (particularly in North America), is inappropriate: patients with treated heart failure should not be congested.3,4
The diagnosis of heart failure requires the combination of symptoms suggestive of the condition, appropriate abnormalities on imaging and raised serum natriuretic peptides (see below).