Causes of heart failure

A major goal of the management of heart failure is to identify likely causes so that specific therapies can be used to improve outcomes. Often the cause of heart failure is apparent from clinical assessment, including electrocardiogram (ECG) and chest X-ray. Other investigations (noninvasive and invasive) may be required for diagnosis and assessment of severity and prognosis. Consider the following in all patients with heart failure:

• High blood pressure (BP) may be the principal underlying cause of heart failure and requires aggressive treatment to lower systemic vascular resistance and left ventricular afterload; see Hypertension and blood pressure reduction for information on management of BP.
• Coronary artery disease may require revascularisation and drug therapy.
• Patients with diabetes mellitus often have associated comorbidities such as elevated BP, kidney disease and coronary artery disease, and may also develop a cardiomyopathy unrelated to coronary artery disease.
• Arrhythmias may both precipitate heart failure or result in left ventricular dysfunction (eg atrial fibrillation with a rapid ventricular response, frequent ventricular ectopy).
• Excess alcohol intake can cause heart failure that may respond to thiamine supplementation. In patients with alcoholic cardiomyopathy, abstinence may improve left ventricular function. For management of alcohol dependence, see Overview of disorders of alcohol use.
• Use of recreational stimulant drugs (eg cocaine, amfetamines) may be suggested by unexplained left ventricular dysfunction, especially if associated with elevated BP.
• Certain cardiomyopathies can be prevented by or respond to specific therapies (eg disease-specific therapies for cardiac amyloidosis, venesection for haemochromatosis, iron chelation therapy for thalassaemia, echocardiographic monitoring and dose adjustment of chemotherapy associated with cardiotoxicity).
• Valvular heart disease may require interventional treatment (eg aortic valve replacement for severe aortic stenosis, mitral valve repair or replacement for severe mitral regurgitation, balloon valvuloplasty or valve replacement for severe mitral stenosis).
• Hyperthyroidism may cause heart failure, particularly in association with atrial fibrillation with rapid ventricular response. A high level of clinical suspicion of hyperthyroidism is necessary, particularly in older patients. For management, see Hyperthyroidism.
• Chronic lung disease should be managed to alleviate cor pulmonale.
• Pulmonary embolism may present with isolated right ventricular failure, requiring specific treatment and investigation for causes; see Venous thromboembolism: treatment.
• Pericardial effusion may require urgent pericardial aspiration if cardiac tamponade is present.

Less common causes of heart failure include inherited cardiomyopathies (including dilated and hypertrophic cardiomyopathy), constrictive pericarditis, other metabolic causes (eg hypothyroidism, phaeochromocytoma), heavy metal toxicity (eg cobalt), radiation therapy, nutritional deficiencies, myocarditis and infiltrative cardiomyopathies.