Atrial fibrillation is the most common persistent heart-rhythm disorder, in which the atria contract chaotically and do not pump blood as they should. Because of this the pulse becomes irregular and blood stagnates in the atria.
The main danger of the arrhythmia is the formation of clots and stroke; it is detected with an ECG. It is one of the key cardiovascular problems with age.
What happens to the heart
Normally the electrical impulse is born in the sinus node and passes through the heart in an orderly way. In fibrillation the atria “quiver” at a rate of 350–600 per minute, and only some impulses reach the ventricles — the rhythm becomes irregular and often rapid.
The arrhythmia can be paroxysmal, persistent and permanent. Its likelihood rises with age and with hypertension, obesity, diabetes, thyroid disease and sleep apnea.
Why it is dangerous: stroke and heart failure
Because blood stagnates in the left atrium, clots form and travel with the bloodstream to the brain — this is how a cardioembolic stroke develops. Atrial fibrillation is one of the leading causes of severe strokes, which is why many patients are prescribed anticoagulants (“blood-thinning” drugs).
A constantly rapid and inefficient rhythm weakens the heart over time and can lead to heart failure and reduced exercise tolerance.
Symptoms and diagnosis
Typical are palpitations and skipped beats, shortness of breath, weakness and fatigue, dizziness, chest discomfort. Often the arrhythmia is asymptomatic and found by chance — which is why an irregular pulse is a reason for an ECG.
The diagnosis is made on the ECG; for rare episodes, 24-hour Holter monitoring or wearable devices are used. In addition, the heart’s structure is assessed on echocardiography and thyroid function is checked.
What you can do
Treatment addresses two tasks: preventing clots (anticoagulants based on individual risk) and controlling the rhythm or rate (drugs, cardioversion, catheter ablation). Managing blood pressure, weight, alcohol and sleep apnea reduces the number of episodes. The approach is set by a doctor — self-treatment is dangerous.
Calculate using this marker
Calculators where Atrial fibrillation is used directly:
Frequently asked questions
Is atrial fibrillation dangerous?
The episode itself rarely threatens life directly, but the arrhythmia sharply raises stroke risk and weakens the heart over time. So it must not be ignored: assessment of clotting risk and follow-up with a cardiologist are needed.
Can atrial fibrillation be cured?
In some patients catheter ablation restores a normal rhythm for a long time, especially in the early stages. But there is no universal “pill”: often the goal is to control the rate and prevent clots rather than eliminate the arrhythmia entirely.