In primary care, if heart failure is suspected, the GP will request a blood test for natriuretic peptide (usually NT-pro BNP). This is released when the heart muscle is stretched. If the level is raised this does not necessarily mean that the patient has heart failure but it does support this as a differential diagnosis and the patient is then referred for an echocardiogram – an ultrasound scan of the heart – that will give a more definitive diagnosis. Since very high levels of NT-pro BNP carry a poor prognosis, patients are triaged for assessment depending on the levels.

Echocardiogram (ECG)

An ECG is the gold standard tool for the assessment and diagnosis of heart failure. The results of the scan will give a detailed assessment of dimensions of the heart’s chambers, assess valvular function and determine if systolic or diastolic dysfunction is present. Importantly, it is used to estimate the ejection fraction (the proportion of blood ejected from the heart with each heartbeat), which will determine both diagnosis and treatment pathway.

Remember that the term heart failure is a broad one and that the ECG will provide the detail needed to confirm the diagnosis as either:

• Heart failure with reduced ejection fraction (HFrEF) where there is a problem with the pumping ability of the heart resulting in a reduction in the volume of the blood expelled each time the heart pumps. The ejection fraction
  is less than 40 per cent
• Heart failure with preserved ejection fraction (HFpEF), which can be harder to diagnose. The problem is more commonly associated with reduced cardiac output as the heart vessels do not relax properly and the ejection fraction is preserved (50 per cent or more), even though other markers of heart failure are present. The incidence of HFpEF occurs in around 50 per cent of heart failure cases.