Atrial fibrillation: why do doctors talk about stroke, and what does treatment look like?

On AFib Matters, the website for patients created by the European Society of Cardiology (ESC) and EHRA, the rhythm in fibrillation is described in English as “irregularly irregular”, that is, completely irregular: even more disordered than ordinary unevenness. Episodes may come and go, especially in the attack-like (paroxysmal) form, and sometimes they are seriously troubling.

Feeling your pulse may raise a suspicion of irregularity, but it cannot reliably confirm it, especially when the heart is beating fast. According to the review of the 2024 ESC/EACTS guideline (Rienstra and co-authors, Europace 2024), the diagnosis is made with a 12-lead ECG or a single-lead recording of at least 30 seconds, in which the atrial waves (P) do not repeat and the R–R intervals are irregular.

The 2024 ESC/EACTS guideline builds treatment on the AF-CARE system. Its four parts:

• C — managing coexisting diseases and risk factors;
• A — preventing stroke and thromboembolism;
• R — reducing symptoms by controlling heart rate and rhythm;
• E — evaluation and regular review of treatment.

Thromboembolism means problems caused by a blood clot traveling with the bloodstream and blocking a vessel; stroke is one of them. That is why this direction is set apart. This does not mean that everyone will have a stroke: the risk differs from person to person, which is why it needs to be assessed.

The risk is assessed with the CHA₂DS₂-VA score. The doctor calculates the score based on information about your health. According to the 2024 ESC/EACTS guideline, an anticoagulant is recommended if the score is 2 or higher, and its use is considered if the score is 1. Anticoagulants are medicines that affect blood clotting, often called “blood thinners”.

The guideline says the following about the choice of medicine:

• Direct oral anticoagulants (DOACs: apixaban, dabigatran, edoxaban, rivaroxaban) are preferred over vitamin K antagonists. The exception is a mechanical heart valve or moderate to severe mitral stenosis.
• Antiplatelet medicines (for example, aspirin) on their own are not indicated for stroke prevention in AF. Adding them to an anticoagulant for the purpose of stroke prevention is not recommended either.
• The risk of bleeding is assessed too. If HAS-BLED is 3 or higher, check-ups should be done early and often, but this by itself is not a reason to give up the anticoagulant.

Only the doctor prescribes the specific medicine and its dose.

According to the 2024 ESC/EACTS guideline, the need for an anticoagulant depends on the risk of stroke. Whether the heart is in fibrillation or in normal sinus rhythm at the moment does not determine it. Rhythm control does not remove this need either. Even after AF ablation, the anticoagulant is continued for at least 2 months, regardless of the risk. Only the doctor decides on changing your medicine plan.

Treatment depends on how the fibrillation behaves: the first-diagnosed, attack-like (paroxysmal), persistent or permanent form. The guideline recommends that the doctor and the patient make decisions together, that a multidisciplinary team supports this, and that the patient and their family are given explanations.

There are two ways to reduce symptoms:

• Rate control: beta-blockers, digoxin or (if the left ventricular ejection fraction, LVEF, is above 40 %) diltiazem or verapamil.
• Rhythm control: cardioversion (a procedure aimed at restoring the rhythm), antiarrhythmic medicines, catheter or surgical ablation. The main goal is to reduce symptoms and improve quality of life.

Catheter ablation is considered one of the first-line options for suitable patients with paroxysmal AF, but not every patient has ablation. In the “C” part of AF-CARE, high blood pressure, heart failure, diabetes, obesity, pauses in breathing during sleep, low physical activity and heavy alcohol use are assessed and managed.

According to AFib Matters, fast and troubling episodes, as well as episodes with shortness of breath, dizziness, fainting or chest pain, need a prompt medical examination. Bring a symptom diary to the appointment: duration, triggers and accompanying symptoms. For diagnosing the rhythm, the most important thing is an ECG recording made during symptoms.