Controlling Risk Factor of Stroke: Atrial Fibrillation

Atrial fibrillation (AF) is a common type of abnormal heart rhythm. In Singapore, 1.5 percent of the population aged 55 years and above have AF. The risk of AF increases with age from 0.1 percent in patients under 55 years old to 10 percent in patients who are 80 years old and above. AF increases the risk of stroke by 5 times.

What is Atrial Fibrillation (AF)?

The heart pumps blood throughout the body. In normal heart function, the four chambers of the heart beat in a coordinated way to ensure consistent blood flow. However during AF, one or both of the upper heart chambers beat irregularly and disrupts the rhythm, which affects blood flow.

How does AF increase the risk of stroke?

When your heart beats irregularly, blood does not flow smoothly through the heart chambers. This can cause blood to pool and form dangerous clots. These clots can break away and travel through your bloodstream to the brain, where they block blood vessels and cause a stroke. 

What are the signs and symptoms?

Some people do not experience any symptoms and are unaware of their AF condition until discovered during a medical examination. 

Those who do have symptoms may experience the following: 

• Fast or irregular (skipped or extra) heartbeat
• Breathlessness
• Chest pain or fatigue
• Dizziness or lightheadedness

What are the Risk Factors for AF?

Common risk factors of Atrial Fibrillation are:

• High blood pressure
• Ischaemic heart disease
• Heart valve abnormalities
• Abnormalities of the heart’s pumping function
• Sick Sinus Syndrome (a type of heart rhythm disorder)
• Diabetes
• Hyperthyroidism
• Overweight and obesity
• Sleep apnea and other sleep problems
• Lifestyle risk such as heavy alcohol intake and smoking 

How is it diagnosed? 

Atrial Fibrillation is usually diagnosed with an electrocardiogram (ECG), which records your heart’s electrical activity. For more detailed assessment, doctors may use prolonged heart monitoring devices such as Holter monitors that track your heart rhythm over 24-48 hours or longer.   

Fitness trackers, smartwatches, and home blood pressure monitors may not accurately detect AF. If you suspect you have an abnormal heart rhythm, consult your healthcare professional for proper testing and diagnosis. 

How is AF treated? 

The aim of treatment is to control the condition and prevent complications. Controlling AF may involve:

• Treating your heart rhythm to make it more regular
• Treating your heart rate to slow it down

Stroke Prevention

Besides treatment for AF, you may also be started on anticoagulants (blood-thinning medications), which help reduce the risk of getting a stroke. Your doctor will discuss with you regarding the use of anticoagulants.

Anticoagulants

Common anticoagulants that are used for stroke prevention relating to AF includes warfarin and the direct oral anticoagulants (DOACs) such as apixaban, edoxaban, rivaroxaban and dabigatran. 

What do I need to know about anticoagulants?

Medication

• Take your medicine daily and follow the dosing instructions.
• You should receive detailed counselling before taking anticoagulation medication.

Reduce risk of bleeding

Anticoagulants can make you bleed longer than normal and bruise more easily. To stay safe, avoid activities that could cause injuries or bleeding. 

Consult your healthcare professionals for advice

• Before taking any new medications, supplements and/or traditional medicines. These products can interfere with your anticoagulants, making them either too strong (increased bleeding risk) or too weak (reduced protection against clots).
• Before any dental or medical procedures, your doctor needs to determine if you should temporarily stop your anticoagulants to prevent any excessive bleeding during the procedure.

Seek medical attention

1. If you have uncontrolled bleeding, or
2. If you experience the following signs of bleeding:

• Persistent nausea, stomach upset, or vomiting blood or other material that looks like coffee grounds
• Excessive menstrual bleeding or bleeding between menstrual periods
• Dark red or brown urine
• Bloody or dark-coloured stool
• Multiple, unexplained bruises

How else can I prevent stroke?

There are other things that you can do to reduce the risk of getting a stroke, such as: 

For more information on how to better manage your stroke recovery journey, visit Stroke E-Resources.

StrokeHub Video: 

Atrial Fibrillation (Extended Version) https://youtu.be/YLMqeLYR1Sw

Atrial Fibrillation https://youtu.be/LPMFZr_qh5Q