Atrial fibrillation: just a quivering heartbeat away from stroke — quote from the Heart and Stroke Foundation of Canada

Atrial fibrillation, also called AF or A-fib, is an abnormal heart rhythm. It is relatively common, affecting 2.5 million American adults. Most people who develop A-fib are over 65 years of age.

In atrial fibrillation, part of the heart (the upper chambers or atria) does not work correctly because of abnormal electrical activity.

This means that blood is not forcefully moved out of these chambers. The blood that remains in the atria becomes “sluggish”, which allows blood clots to form. With that comes a risk of stroke.

Atrial fibrillation causes

A-fib increases in frequency with ageing and typically occurs in people who have underlying heart disease.

Almost any cardiac disease can increase A-fib risk, but the most common causes are high blood pressure, heart attack, cardiac failure, valve disease or after a heart surgery. Non-cardiac causes include diabetes, overactive thyroid, lung disease, and alcohol.

Binge drinkers can develop A-fib that is usually transient, over weekends or holidays when alcohol intake is excessive — holiday heart syndrome.

In addition, stimulants like caffeine can precipitate A-fib episodes.

Sleep apnoea, a condition where patients stop breathing for prolonged periods of time while sleeping, can cause A-fib. Some people with A-fib have no apparent cause, but likely a genetic predisposition; they are usually under 65 years of age.

Atrial fibrillation symptoms

Some people have no symptoms at all while others have a variety of symptoms: palpitations, difficulty breathing at rest or with exertion, lightheadedness, fainting, fatigue, and chest discomfort.

A serious complication associated with A-fib is stroke. If a blood clot forms in the left atrium because of sluggish blood flow, a piece of it, called “embolus”, can break off and enter the blood circulation, blocking a small blood vessel. If this happens in the brain, a stroke can occur. The embolus may also travel to other organs. Without preventive treatment (eg blood thinners), stroke occurs in 1.3 per cent per year of people with A-fib aged 50-59 years, and increases gradually to seven per cent per year for people 80-89 years old.

Atrial fibrillation diagnosis

A-fib is diagnosed with an electrocardiogram (ECG or rhythm tracing) or a heart monitor. A cardiac ultrasound may be performed to look for heart weakness or valve problems. Blood work, sleep study and lung function tests may be used to look for thyroid problems, sleep apnoea or lung disease, respectively.

Atrial fibrillation treatment

Electrical cardioversion: Involves the use of an electrical shock delivered by paddles placed on the chest, to “reset” the heart rhythm.

Rhythm control: A strategy in which efforts to restore and maintain a normal heart rhythm (sinus rhythm) are carried out. After successful conversion to a normal rhythm, only 20-30 per cent of people are still in sinus rhythm after one year without antiarrhythmic drug therapy. This can be increased to 50-60 per cent by the addition of an antiarrhythmic drug. The advantages to rhythm control include improved cardiac function and, for some people, reduced symptoms. Rhythm control is more likely to reduce A-fib frequency than eliminate it entirely. Thus, many people treated with antiarrhythmic medications continue blood thinners, indefinitely.

Rate control: People who are treated with rate control continue to have A-fib. However, the person uses a medication (not antiarrhythmics) to slow heart rate and dampen symptoms.

Radiofrequency ablation: A procedure that can sometimes cure A-fib. The technique, however, is still evolving, and there is a small but real risk of serious complications, even with experienced doctors.

Surgery: A consideration for some AF patients, especially those undergoing heart surgery for other reasons.

Treatment to prevent clots

Anticoagulant drugs: Blood thinners can reduce the risk of having a stroke by 70 per cent. Warfarin has been used for many years. Its dosing requires monitoring with periodic blood tests. Pradaxa, Eliquis, Xarelto, and Savaysa (or Lixiana) are newer anticoagulants that work as well as Warfarin and are as safe but do not require periodic blood tests. Antiplatelet drugs: Aspirin and Plavix are the least effective treatment for stroke prevention and should only be used if blood thinners are contraindicated.

Joe Yammine is a cardiologist at Bermuda Hospitals Board. He trained at the State University of New York, Brown University and Brigham and Women’s Hospital. He holds five American Board certifications. He was in academic practice between 2007 and 2014, when he joined BHB. During his career in the US, he was awarded multiple teaching and patients’ care recognition awards. Disclaimer: the information herein is not intended as medical advice nor as a substitute for professional medical opinion. Always seek the advice of your physician. You should never delay seeking medical advice, disregard medical advice or discontinue treatment because of any information in this article