Professor Christian Hamilton-Craig and Dr Karen Phillips
Atrial fibrillation, or “AF”, is the most common heart rhythm disorder in our community, particularly affecting people over the age of 50.
It is a rhythm disturbance in the top chambers of the heart which causes the heart to beat in an irregular fashion. AF is not just a heart rhythm problem, however.It is often an indicator of other heart or health problems such as high blood pressure, obesity and sleep apnoea which may need to be checked out and addressed.
AF is not a heart attack (heart muscle damage from a blockage of a heart artery). AF can have serious long-term effects on the pumping function of the heart, however.
The other serious problem with AF is that it significantly increases the risk of stroke, particularly as people age. When the heart rate is irregular, then tiny clots can form inside the atria; these clots can travel in the blood stream to the brain causing stroke through lack of blood supply to an area of the brain.
AF is one of the leading causes of stroke in the world, in addition to high blood pressure and smoking
Some people with AF may experience palpitations, breathlessness and tiredness, while other people have no symptoms at all.
AF can generally be detected from its irregular pulse.
Checking your pulse by feeling it at the wrist, checking it with an AF app on a smartphone, and /or having a heart rhythm tracing (ECG) with your doctor can help diagnose AF.
Sometimes AF can come and go spontaneously (paroxysmal AF), whereas for other people the AF can be continuously present unless the rhythm is reverted to normal with medication or an electrical zap from direct current cardioversion (performed in hospital under anaesthetic).
Treatment for AF depends on how long it has been present, any associated symptoms or heart problems, and the underlying cause of the rhythm problem. The goals of treatment are to either reset the heart rhythm to normal or to control the heart rate. This prevents the heart from racing and prevents the formation of blood clots that can lead to stroke.
Strokes caused by AF can cause lifelong disability. It can be prevented by taking blood thinning medication if the risk of stroke is estimated to be sufficiently high. The risk of stroke can be estimated by adding up a CHA2DS2-VASc score, which gives a score from one to nine based on the presence of risk factors such as congestive heart failure, hypertension, age > 65, or >75 (2 points), diabetes, previous stroke/TIA (2 points), female gender if over age 65, and vascular disease. Very low risk patients with a score of 0 should not need anticoagulation (blood thinners), but those with a score of >1 should have long- term anticoagulation to prevent stroke.
In the past, warfarin was used as the main blood thinner for AF but this medication was often tricky to use as it required regular blood tests and dose adjustment.
Fortunately, newer anticoagulant medications (Direct Oral Anti-coagulants or DOACs) are easy to take, and have been shown to be equally as effective as warfarin with lower bleeding risk and no blood tests. Three different DOACs are available in Australia, Xarelto (rivaroxaban), Eliquis (apixaban), and Pradaxa (dabigatran). There are different pros and cons to each of the medications and your doctor would usually advise on the recommended medication or discuss the options with you. Patients that are not suitable for anticoagulant medications may be offered a left atrial appendage occluder implant, which is like a plug inserted keyhole into the heart (using a wire through a vein) to reduce the risk of stroke.
Most people who have AF with symptoms or in association with weakened heart function may be suitable for ablation. This is another keyhole procedure using wires to access the heart (through the veins in the leg). Ablation uses heat (radiofrequency) or cold (cryoablation) to treat the abnormal electrical impulses which cause AF at their source inside the heart and helps restore normal rhythm. Ablation is a specialist technique performed by experienced heart rhythm cardiologists (also called cardiac electrophysiologists) and may sometimes require more than one procedure to be successful. But evidence is increasing that early ablation leads to improved long term heart health and longevity, and clinical practice is slowly shifting towards up-front ablation sooner for suitable patients with new AF.
Recently more people in the community are wearing devices which monitor heart rate such as Apple Watch, other smartwatches or Fitbits. These devices can sometimes indicate an irregular heart rate which may be AF. This is useful information which you should share with your GP. Early detection of AF in the community may lead to better stroke prevention through early treatment of AF.
Stroke prevention has become a focus of the Australian national health targets, and early detection of AF is a key strategy for stroke prevention. If you are over the age of 65 ask your doctor to check your pulse at your next check up.
If you have a family history of either AF or stroke, if you have had AF in the past, or your wearable device has noticed an irregular pulse, please contact your doctor or your local cardiologist for a more detailed check up with an ECG (rhythm tracing) and an cchocardiogram (ultrasound of the heart).
When it comes to early detection of AF, a stitch in time will definitely save nine.
Healthy Hearts: each month Prof Christian Hamilton-Craig, local cardiologist living in Noosa Shire, talks about important issues for maintaining your heart health.
This column has been co-authored with Dr Karen Philips from the Brisbane AF Clinic brisbaneafclinic.com
