Atrial fibrillation (AF) is a condition where the heart beats irregularly or rapidly. While AF itself is not dangerous, it’s important to diagnose and treat it because it increases the risk of other conditions, such as heart failure and stroke.
In AF, blood circulates in the heart in an abnormal way, so there is a tendency for clots to develop. These clots can break off and travel to all areas of the body in the bloodstream. If a clot blocks the brain artery, this can cause a stroke.
Symptoms of AF include an irregular pulse, heart palpitations or a ‘fluttering’ heartbeat, dizziness, tiredness and weakness. However, people often have no symptoms at all or only experience symptoms some of the time.
AF is very common, with nearly two in every 100 people in New Zealand currently living with the condition – more than 80,000 Kiwis.1 AF becomes even more common with age.
AF can occur in both men and women, and can occur at any age, though it is more common in those over 75 years of age. The most common causes of AF are ageing, having long-term high blood pressure or coronary heart disease, although the cause is not always known.
AF occurs more commonly at a younger age in Mäori and Pacific peoples than in other New Zealanders.
Over the age of 40, you have a 1 in 4 lifetime risk of AF. As you get older, your risk of developing AF increases. About 7 per cent of people over 65 have AF, and this increases to 10 per cent over the age of 75.2 At this stage, screening for the condition becomes even more important due to the increased risk of an associated stroke.
The risk of stroke is present even when AF is only experienced some of the time. One in every three strokes is linked to AF, and AF-linked strokes are more severe than other strokes. The risk is also higher if you have high blood pressure or diabetes, have had a previous stroke, or if you have heart failure or other conditions that might predispose you to stroke.
Screening for AF
To screen for AF, your doctor may do some tests including feeling your pulse or taking an electrocardiogram. Once AF is diagnosed, medication can be prescribed to successfully manage the condition or help stop clots forming inside the heart.
Your pulse can indicate how well your heart is working, how fast it beats, and its rhythm and strength. Keeping a record will help you notice if there is anything different or unusual with your results.
A normal pulse, or resting heart rate, ranges from 60 to 100 beats per minute. Your pulse should beat steadily and regularly. A pause or extra beat now and then is normal, but if you notice frequent skipped or extra beats, speak to your doctor. Also speak to your doctor if your pulse is consistently outside the normal range, as this may indicate an underlying problem.
What is HRI doing?
HRI is tackling the widespread problem of AF from a broad range of research angles. Our Heart Rhythm and Stroke Prevention Group is currently investigating further strategies to screen for AF, amongst other related projects.
- Tomlin AM; Atrial fibrillation in New Zealand primary care: Prevalence, risk factors for stroke and the management of thromboembolic risk. Eur J Prev Cardiol. 2017 Feb;24(3):311-319.
- Atrial Fibrillation Association Australia. Atrial Fibrillation (AF) Patient Information. 2013.