ABSTRACT
Heart failure is a clinical syndrome arising as a consequence of the body’s response to a heart that is unable to provide a physiologically appropriate output under normal loading conditions. It can occur as the result of any abnormality of the structure or function of the heart.1 Until the 1980s, understanding of heart failure was based on a haemodynamic model, exemplified by Paul Wood’s 1950 definition: ‘A state in which the heart fails to maintain an adequate circu lation for the needs of the body despite a satisfactory filling pressure.’2 Recognition that many cases involved increased peripheral vasoconstriction and reduced cardiac
Cardiac failure is a clinical syndrome comprising a triad of breathlessness, fatigue and fluid retention. These symptoms can be the result of any disorder, genetic or acquired, affecting the structure or function of the heart in a manner that impairs its ability to act as an efficient pump. Heart failure is not a stand-alone diagnosis – identification of the aetiology and how the body has responded to the cardiac dysfunction is key to providing optimal management of the individual patient. The syndrome can develop relatively suddenly (acute de-novo heart failure), or can be present for many months or years (chronic heart failure). Acute decompensation of the chronic syndrome is not infrequent, particularly where compliance with treatment is poor, monitoring is sub-standard, or with intercurrent illness. The syndrome is characterized by cardiac dysfunction, consequent haemodynamic changes attempting to maintain circulatory homeostasis, changes in breathing pattern, sodium and fluid retention through renal and neurohormonal mechanisms, changes in muscle blood flow, and immune activation. In suspected heart failure, the physician should remember that identification of the syndrome is based on history and examination combined with appropriate investigations; a normal resting electrocardiogram should raise doubt regarding the validity of the diagnosis; plasma natriuretic peptide levels can help to establish the diagnosis; and echocardiography should be used to image the heart for quantifiable determination of cardiac structure and function. Where heart failure is confirmed, management consists of lifestyle measures and the introduction and optimization of medications such as diuretics, inhibitors of the renin-angiotensin-aldosterone axis, and selected -blockers. For patients fulfilling certain criteria, implantable defibrillators or cardiac resynchronization therapy can also decrease mortality and, in the latter case, improve symptoms. Despite improvements in our understanding of the pathophysiology, and a wider range of therapeutic options, heart failure remains a serious condition, with considerable morbidity and mortality. A condition largely of the elderly, its prevalence is set to rise as the population ages. Optimal management requires close monitoring of the syndrome, multiple medications and increasingly some form of implantable electrical device therapy. Communication between the patient and all professionals involved in their care is essential in optimizing the outcome.
