Symptom classification in atrial fibrillation

What it is and when to use it

The EHRA (European Heart Rhythm Association) symptom scale, in its modified version (mEHRA), classifies the intensity of atrial fibrillation-related symptoms and their impact on the patient's daily activity. It does not estimate thromboembolic or bleeding risk; rather, it standardizes symptom burden to guide rhythm-control decisions and monitor treatment response. It is the symptom-quantification tool recommended by the ESC atrial fibrillation guideline and is embedded within the structured approach to AF management.

How to interpret it

The score assigns one of four classes. EHRA 1: no symptoms. EHRA 2a: mild symptoms, normal daily activity not affected. EHRA 2b: moderate symptoms, normal daily activity not affected but the patient is troubled by symptoms. EHRA 3: severe symptoms, normal daily activity affected. EHRA 4: disabling symptoms, normal daily activity discontinued. The key distinction between 2a and 2b is whether symptoms trouble the patient; between 2b and 3, whether they objectively affect activity. A class of 2b or higher generally supports a rhythm-control strategy.

Limitations and when not to use it

The scale has been validated in adult patients with atrial fibrillation and measures only symptoms attributable to AF (palpitations, dyspnea, fatigue, dizziness, chest pain). It is a subjective, interview-dependent assessment, not an objective instrument. A frequent error is attributing to AF symptoms actually caused by comorbidities (heart failure, pulmonary disease, anemia). It does not assess stroke or bleeding risk and does not replace CHA₂DS₂-VASc or HAS-BLED, nor does it by itself guide the decision to anticoagulate.

Frequently asked questions

What is the difference between EHRA 2a and 2b?

In both, normal daily activity is preserved, but in 2a symptoms are mild and not bothersome, whereas in 2b they are moderate and the patient is troubled by them.

Is the EHRA scale used to decide on anticoagulation?

No. The EHRA scale only quantifies symptoms; the decision to anticoagulate is based on stroke risk measured with CHA₂DS₂-VASc.

What is the modified mEHRA version?

It is the current version that splits class 2 into 2a and 2b based on whether symptoms trouble the patient, and it is the one recommended by the ESC guideline.