Atrial fibrillation (AF) is a disturbance of the electrical system of the heart. It is the most common of a number of disorders referred to as ‘arrhythmias’ or ‘dysrhythmias’, in which the heart beats with an abnormal rhythm, and does not pump blood regularly or work as efficiently as it should (Verma & Wong 2019; NHFA 2016).
AF can vary in severity, from occasional episodes of electrical disturbance, to a chronic condition that can result in impairment of how the heart works, leading to poorer quality of life and a risk of stroke and/or heart failure.
Symptoms and causes
Often, people with AF do not know that they have it, and they do not experience any symptoms. Others may experience an irregular pulse, heart palpitations (‘fluttering’), fatigue, weakness, discomfort, shortness of breath or dizziness.
The risk of developing AF is substantially higher in elderly individuals. Common causes of AF include long-term high blood pressure, coronary heart disease and valvular heart disease. Other risks for AF include obesity, having a thyroid condition, diabetes, chronic kidney disease, obstructive sleep apnoea, and smoking or consuming alcohol excessively. For some people, there is no apparent cause.
Stroke and heart failure risk
AF greatly increases the risk of stroke and strokes associated with AF are more severe, with a risk of death twice that of other stroke causes. An individual’s risk may be even higher if their AF is associated with previous heart disease or with other chronic diseases (NHFA 2016). Primary care plays a key role in identifying AF, assessing the risk of stroke and commencing anticoagulant drug treatment when the benefits outweigh the risks.
Heart failure occurs more commonly than stroke in patients with AF (Odutayo et al. 2016). AF can lead to heart failure, and heart failure puts patients at greater risk for AF. AF and heart failure share risk factors, and patients who have both have more severe symptoms, and are at greater risk of mortality (Anter et al. 2009).
Treatment for AF includes medications to control heart rate, and to thin the blood to prevent clotting and reduce the risk of having a stroke (AIHW 2017). Medication and lifestyle changes also help to manage common risk factors for cardiovascular disease (CVD).
People with prolonged or severe AF may undergo cardioversion. Electrical cardioversion is a hospital procedure which delivers a small electric shock to the heart to restore and maintain normal rhythm. Pharmacological cardioversion uses medicines to achieve the same purpose. After cardioversion, long-term medicines are often prescribed to help prevent AF from reoccurring.
Certain patients with AF benefit from ablation—this is a hospital procedure which inactivates small areas of tissue in the heart responsible for the abnormal electrical signals associated with AF.
The social, economic and public health impact of AF in Australia is growing. This can be attributed to a number of factors, including population ageing, changes in risk factor prevalence, better detection and improved CVD survival rates.
Clinical advances over recent decades have improved our understanding of the evolving impact of AF, leading to increased surveillance and improved diagnosis and treatment.
For more information on AF burden of disease and expenditure, see the Impact chapter.