Relevance of the aetiology of heart failure to drug therapy.

The phrase 'heart failure' is used as a shorthand by medical practitioners to describe a wide variety of medical conditions ranging from acute heart failure with pulmonary oedema to terminal chronic heart failure. The medical treatment of these entities varies widely and is dependent on an understanding of the haemodynamics, pathophysiology and aetiology of the conditions, and on the pharmacology of the drugs selected. Important distinctions should be made between systolic and diastolic, acute and chronic, and extracellular and cellular heart failure. Drugs often used for treatment include diuretics, angiotensin-converting enzyme (ACE) inhibitors, nitrates and digoxin. Pure positive inotropic drugs are of value in the treatment of circulatory collapse, post-operatively and in terminal heart failure. Drugs with a mild positive inotropic effect which also possess other properties such as systemic vasodilation, renal vasodilation and alteration of diastolic function may be of wider value in the treatment of mild to moderate chronic heart failure but that prediction awaits proof from controlled clinical trials.