A silent killer is stalking many families across Australia, taking victims with little notice while driving a black-hole in the country’s health budget. But a simple pulse check may be enough to detect this harmful and costly condition.
Every year, as many as three million people across the world will have a stroke attributable to abnormal heartbeats called atrial fibrillation. This is equivalent to one person every ten seconds.
Atrial fibrillation is the most common abnormal heartbeat that affects almost 400,000 Australians, and it can produce potentially lethal clots that are responsible for one in six strokes.
Stroke is usually rapid in onset and devastating for individuals and their families. It often leaves the sufferer with physical disability and impairment. In Australia, it’s the second biggest cause of death after heart disease.
The National Stroke Foundation estimates that approximately 53,000 people are affected by stroke each year, at the cost of A$1.3bn. But beyond the financial impact is the direct effect on the workforce and communities, hard-hit with the loss of productivity and loved ones.
But many strokes can be prevented if symptoms are recognised and help for getting the appropriate treatment is sought.
What is atrial fibrillation?
Atrial fibrillation occurs when chaotic and disorganised electrical activity replaces the regular pace of the heart in the upper chambers (atria). This stops the atria from beating in a regular rhythm and the heart’s efficiency to pump blood is reduced. This can cause clotting (stasis) of the blood in the upper chambers of the heart.
When the heart does provide an effective pump of blood again, the clot may be passed from the heart via the blood vessels to the brain causing a stroke.
The risk of stroke is thought to be five or six times greater in patients with atrial fibrillation compared to those with a normal heart rhythm. In addition, the burden from atrial fibrillation is set to increase at least threefold by 2050 as the population ages and cardiovascular disease remains common.
Risk factors and causes
Atrial fibrillation is more prevalent in the elderly, male Caucasian population. Well-established risk factors include heart failure, disease of the heart valves, heart attacks, high blood pressure, diabetes and sleep apnoea.
Lifestyle factors including smoking, excessive alcohol intake and caffeine consumption, combined with obesity and elevated stress levels increase risk. There’s also a growing body of evidence suggesting that avoiding consuming energy drinks, with their high levels of caffeine, and excessive sport can reduce an individual’s risk.
Signs and symptoms
The signs and symptoms of atrial fibrillation vary and it’s often very difficult to diagnose because of its silent nature and vague set of symptoms. The symptoms may include palpitations, shortness of breath (dysponea), chest pains, low blood pressure (hypotension), reduced ability to participate in exercise, fatigue, general malaise, dizziness and light-headedness, panic attacks, fainting (syncope) and a tendency to produce lots of urine (polyuria).
Having a health professional manually check your pulse remains one of the quickest and most reliable ways of checking for irregularity of your heart rate and rhythm. If an irregular heartbeat is suspected, an ECG can be performed to trace the heartbeat and assist clinicians in diagnosis.
Treatments
There are many treatments available for atrial fibrillation to reduce the risk of stroke. These include defibrillation (electrical cardioversion) or invasive procedures such as catheter ablation (when a series of thin, flexible wires are put into a blood vessel in and guided into your heart through that blood vessel to restore order to the electrical pathways in the heart), blood thinning medications and medications to correct the rhythm and rate of the heart.
Current advances in therapies include newer blood thinning medications and implantable devices.
More information:
Experiencing palpitations, feeling faint or short of breath? Talk to your doctor.
Stroke is an emergency. If you think you’re having a stroke, call 000
Atrial Fibrillation Association
National Stroke Foundation, Australia
See more Explainer articles on The Conversation.
Paul Rogers
Manager
Thanks for the article.
Regarding risk factors, I'm not aware that any large prospective studies like the Nurses Health Study or EPIC have found any increased risk of stroke associated with caffeine/coffee/tea consumption. In fact, several studies suggest a lower risk of stroke in women coffee drinkers up to at least 3 cups/day.
In another study, male smokers who drank the most coffee (>8 cups/day) had lower (ischemic) stroke risk than those who consumed the least.
Very high doses may have some effect on AF, but I would be interested in the evidence if it exists for stroke risk.
Athletes, especially very fit endurance athletes, do suffer from heart beat irregularities, some possibly AF, but physical activity protects against stroke in most large cohort studies, and I know of no data that athletes are at higher stroke risk than non-athletes or the sedentary.
Seamus Gardiner
Citizen
Paul,
I agree I query the strenuous exercise related risk to AF. I found the study but could not access the paper so am blind to the quality of the study but I wouldn't draw too many conclusions from it. I take your point, Paul, that physical exercise is regarded as a cardio protective factor rather than a risk... How would one define 'strenuous exercise' I wonder? How many bpm for how long?
Patricia/Caleb can you elaborate on this? Can I expect to have a higher risk of AF after being an amateur athlete all my adult life?
Paul Rogers
Manager
Sean, from experience I know that marathoners get missed beats and PVCs, at rest, but in my case never during running (that I noticed) -- and several stress echos found no abnormalities.
A cardiologist I spoke to recently suggested that AF in athletes was of no greater incidence than in the general population, which is not say that it does not occur. Arrhythmias in highly-trained endurance athletes seem somewhat common and whether they are benign or not is for the cardiologists to diagnose. Eg…
Read moreCaleb Ferguson
Lecturer (Faculty of Health) & PhD Candidate (Centre for Cardiovascular & Chronic Care ) at University of Technology, Sydney
Hi Paul & Sean,
Many thanks for your comments; it's really nice to see such conversation.
I think it is important to differentiate between risk factors for developing AF and risk factors for stroke. However, having a persistent cardiac arrhythmia would significantly increase one’s risk of stroke.
There is a growing body of evidence that supports excessive caffeine intake (particularly excessive consumption of highly caffeinated energy drinks) as a risk factor for the development of cardiac…
Read moreSeamus Gardiner
Citizen
Caleb, thanks for taking the time to reply. It's an interesting topic. I'm certainly used to seeing fit patients with paroxysmal arrhythmias, the evidence for sustained AF in endurance athletes is new to me.
I'll look further (for my own interest mainly) but the questions I'm interested to uncover are age of onset, pathophysiology, risk and association with duration and type of exercise. Thanks for the links.
As for caffeine, an interesting exercise is to have a couple of double shot coffees and attach yourself to a monitor... the PVCs and runs of tachyarrythmias are wondrous to behold!
Paul Rogers
Manager
Caleb, thanks for the Schoonderwoerd study. It certainly seems to confirm that AF is higher in endurance athletes.
The next thing would be to explore whether this actually increases stroke risk, or if the developmental cardiovascular changes in such athletes produces a different stroke risk profile.
Cheers.