Heart failure is a complex clinical syndrome, with diagnosis based on typical symptoms, signs and supportive investigations. Investigations may include an electrocardiogram and chest x-ray, but echocardiography is the definitive test. Plasma B-type natriuretic peptide levels may also be useful in diagnosis among patients with breathlessness, particularly as a rule-out test.Mainstay therapy for heart failure comprises lifestyle modification, pharmacotherapy and referral to a multidisciplinary heart failure program.Drug therapies focused on blockade of key activated neurohormonal systems are well established in systolic heart failure. First-line pharmacotherapy consists of angiotensin-converting enzyme (ACE) inhibitors (or angiotensin receptor blockers if the patient is intolerant to ACE inhibitors) and β-blockers. These medications should be commenced at a low dose and slowly up-titrated to the maximal tolerated dose. In selected patients, device-based therapies are a useful adjunct in systolic heart failure. The most common of these are implantable cardioverter defibrillators and cardiac resynchronisation therapy. Most patients will receive both, as the indications overlap. Multidisciplinary approaches, including involvement of the patient's general practitioner, are strongly recommended.