Atrial Fibrillation: The silent disease responsible for one third of strokes in Portugal

Article by Professor João Pedro Marto, Neurologist at ULS Lisboa Ocidental and member of the Portuguese Stroke Society.

The heart can sometimes present changes in its electrical activity, causing what we call arrhythmia . The most common and clinically relevant is atrial fibrillation (AF) .

In this condition, the heart beats irregularly and uncoordinatedly, especially in the atria (the upper chambers of the heart), which stop contracting effectively. This encourages the formation of clots inside the heart, which can be released into the circulation and cause an artery to become blocked. The most serious consequence is an ischemic stroke , caused by the interruption of blood flow to part of the brain.

AF is a common disease: it affects around 2.5% of the Portuguese population over 40 years of age and more than 6% over 60 years of age . This arrhythmia increases the risk of ischemic stroke by five times and is responsible for around a third of strokes in Portugal . Furthermore, strokes associated with AF are usually more severe , with a higher risk of permanent disability or death.

AF is also associated with other serious complications, such as heart failure and dementia .

Among the main risk factors for the development of AF are: aging , high blood pressure , diabetes , obesity , sleep apnea , heart disease , smoking and excessive alcohol consumption , among others.

In many cases, AF is asymptomatic . When it does occur, it can cause palpitations (a sensation of a fast or irregular heartbeat), dizziness , tiredness or even fainting . Diagnosis requires an electrocardiogram (ECG) or Holter-ECG (continuous recording over 24 hours).

After diagnosis, in most cases, anticoagulants are recommended to reduce the risk of stroke. There are also medications and minimally invasive procedures that help control symptoms and prevent complications.

Adopting a healthy lifestyle and controlling vascular risk factors are essential to prevent the onset of AF. If you experience symptoms, seek medical evaluation. If you are prescribed an anticoagulant, do not stop taking it without medical advice.