Written by epgonline.org - Last updated 29 May 2018
Congestive heart failure in simple terms is failure of the heart as a pump. Prevalence is rising, as it tends to affect people later in life and is also most commonly a result of ischaemic heart disease; this trend is likely to continue as the population becomes proportionally older, and survival with established heart disease improves. Epidemiological evidence is variable depending on what criteria and method of diagnosis are used; in the western world, estimates of around 8% in the over-75 group for symptomatic disease are consistent, while echocardiogram studies have shown reduced cardiac function in over 15% of people aged 65 and above.
Congestive heart failure can be separated into diastolic and systolic dysfunction, which reflects whether it is a reduced ejection fraction or a filling defect that results in increased venous congestion. It is this venous congestion in the pulmonary and systemic circulation that results in oedema, causing dyspnoea, swollen peripheries and ascites. Inadequate perfusion pressures lead to activation of the renin-angiotensin-aldosterone system, resulting in fluid and sodium retention and vasoconstriction. These are detrimental in the long-term, worsening congestion further, and placing increased strain on the heart.
The most common symptoms are dyspnoea and fatigue – both of which result from pulmonary oedema. Orthopnoea and paroxysmal nocturnal dyspnoea are symptomatic variations that may allow clearer discrimination between oedema and other causes of dyspnoea. Other symptoms include angina, peripheral oedema and ascites. The most discriminating clinical signs are the presence of a third heart sound, creating a ‘gallop’ rhythm, and an elevated jugular venous pressure.
Diagnosis can be accomplished via echocardiography, while biomarkers such as NT-proBNP can also help to provide information. More discriminating tests such as cardiac catheterisation can give detailed information on the pressures – but are rarely used in practice. Other tests that provide useful background are serum electrolytes, chest x-ray and ECG.
Accurate prognosis is difficult to estimate, as different patient selection and diagnostic criteria have resulted in variable outcomes from studies. In general, the prognosis is poor, with 5-year survival rates frequently found to be less than 50%, a significant proportion of mortality is due to sudden-cardiac death.
Optimal early medical management will usually be with ACE-inhibitors, angiotensin-II blockers and beta-blockers, while there is a role for positive ionotropes in acute and advanced disease. More radical treatment for end-stage disease can include implantable defibrillators, ventricular assist devices and eventually transplantation.
More information on heart failure can be found in the acute and advanced heart failure knowledge centre, providing detailed discussion of the background of the condition.