Diagnosis of heart failure involves a clinical examination for signs and symptoms followed by laboratory and imaging studies. Some of the steps in the diagnosis of heart failure include:

• Clinical examination for signs and symptoms including dyspnea or shortness of breath, edema in the ankles or feet or legs, cough, collection of fluids in the abdomen (ascites) and enlarged liver.

• Laboratory tests include blood tests such as:

  • Routine blood tests to check haemoglobin, full blood count and electrolytes levels, for example
  • Renal or kidney function tests including blood urea, blood creatinine and 24-hour urine output
  • Liver function tests including blood bilirubin and liver enzymes such as AST (aspartate transaminase) and ALT (alanine transaminase)
  • Thyroid function tests
  • C-reactive protein to detect infection
  • Blood cholesterol and lipid profile
  • Blood sugar to check for diabetes or its control
  • A raised B-type natriuretic peptide (BNP) is a specific test for heart failure
  • Markers for heart attack such as cardiac troponin T may be checked

• Electrocardiography may be performed to check for ischemic heart disease, myocardial infarction, arrhythmias or heart rhythm abnormalities.

• Imaging studies include tests such as:

  • Echocardiography - This helps confirm a diagnosis of heart failure. In this test, a device is used to look at the amount of blood entering the heart during diastole and the amount leaving the heart during systole. The device can detect valve and blood flow alterations. Stroke volume (SV), end diastolic volume (EDV), systolic volume and the SV in proportion to the EDV (also called ejection fraction, EF) is determined. A normal EF is between 50% and 70% but in heart failure, this is reduced.
  • Trans-oesophageal echocardiography - This is a form of echocardiography which involves an ultrasound probe being placed in the food pipe or the esophagus where it can detect heart abnormalities.
  • Chest X-rays are used to detect enlargement of the heart.
  • Angiography - This is used to determine the presence of coronary heart disease.