Atrial fibrillation (AF), not to be confused with atrial flutter, is the term used to describe an irregular or abnormal heart rate. While AF and atrial flutter are similar, AF has more serious health implications such as an increased risk of having a stroke or a blood clot (thrombosis). 

    The resting heart rate of someone without AF is usually between 60 and 100 beats per minute1 but this number is usually over 100 beats per minute in AF. 

    It is usually the result of an underlying condition such as hypertension (high blood pressure) or having an overactive thyroid but may develop for no known reason. In this circumstance, the person is said to have ‘lone atrial fibrillation’. AF can affect people at any age but is rare in children and is more common in the elderly populatio