Screening for Atrial Fibrillation

The prevalence of atrial fibrillation (AF) in the general population is 2–4 %.

The prevalence of AF increases with age. AF affects

2 % of individuals aged <65 years
9 % of individuals aged >65 years

Prevalence of atrial fibrillation and age
AF prevalence	Age
2 %	<65 years
9 %	>65 years

The aim of screening is to diagnose AF at a stage when AF is asymptomatic, or when the patient has non-specific symptoms: weakness, fatigue, vertigo, etc.

AF begins as paroxysmal episodes that are triggered by atrial arrhythmias originating from the region of the pulmonary vein ostia. These initial AF paroxysms terminate spontaneously within 24 h, and in 30–50 % of patients they are asymptomatic or present with non-specific symptoms: weakness, fatigue, vertigo, etc.

10 % of patients have silent AF, which carries the highest risk of thromboembolism (particularly stroke). These patients are unaware that they have AF and therefore do not receive anticoagulation therapy according to the CHA₂DS₂-VA score.

In clinical practice, the terms asymptomatic and silent AF are often confused:

Asymptomatic AF: the patient has diagnosed AF and has no symptoms.
Silent AF: the patient has undiagnosed AF and has no symptoms.

Illustration of atrial fibrillation screening using wearable devices, single-lead ECGs, and ambulatory monitoring systems.

Silent atrial fibrillation
10 % of patients have silent AF. Patients have no symptoms and are unaware that they have AF.
30–50 % of patients in the early stage of AF during paroxysms are asymptomatic or have non-specific symptoms (weakness, fatigue, vertigo).

For AF screening, any device that records the electrical activity of the heart based on the voltmeter principle and displays this activity as an ECG tracing is recommended:

Smart devices with ECG (ECG watches, blood pressure monitors with ECG, ECG cards)
12-lead ECG
ECG Holter monitoring
Implantable loop recorder

A major advantage of smart devices with ECG is that patients carry them at all times (ECG watches). The patient can therefore record an ECG during symptoms (palpitations, etc.), which may occur, for example, once per month.

When AF is detected using smart devices with ECG, the patient must immediately contact a physician for comprehensive evaluation and initiation of anticoagulation therapy according to the CHA₂DS₂-VA score.

Screening for atrial fibrillation and devices

Class

For AF screening, any device capable of recording an ECG is recommended:

Smart device with ECG (ECG watches, blood pressure monitors with ECG, ECG cards)
12-lead ECG
ECG Holter monitoring
Implantable loop recorder

For AF screening, devices that do not record an ECG may be considered:

Pulse palpation
Pulse detection during blood pressure measurement with a device that does not record an ECG tracing
Pulse detection based on photoplethysmography (PPG)

Smart watches
Smart bands
Oximeter

IIb

The diagnosis of atrial fibrillation based on ECG must be confirmed by a physician in an outpatient setting, or online via a trusted platform, e.g. www.ECGsmart.com

Investigations or devices that do not record an ECG should not be used for AF screening:

Pulse palpation
Pulse detection during blood pressure measurement with a device that does not record an ECG tracing
Pulse detection based on photoplethysmography (PPG)

Smart watches
Smart bands
Oximeter

Photoplethysmography (PPG) is pulse measurement using light. The device continuously emits light (most commonly green), which is reflected from the pulsating artery. The device then detects the reflected light and determines the pulse rate. Devices that measure pulse based on PPG include smart watches, bands, or an oximeter.

The main limitation of atrial fibrillation screening is that the patient may not experience an AF episode at the time the ECG is recorded. The most effective AF screening method would be implantation of a loop recorder; however, this is not routinely performed because it is an invasive procedure associated with risks (infection, haematoma) and would be financially demanding.

Implantation of a loop recorder is indicated in patients after ESUS (Embolic Stroke of Undetermined Source).

Diagram of atrial fibrillation screening in asymptomatic patients over 40 years of age using regular ECG examinations.

Screening for atrial fibrillation in asymptomatic patients (>40 years)	Class
It is recommended to record an ECG using a smart device with ECG (ECG watch, blood pressure monitor with ECG, ECG card) once every 3 months.	I
It is recommended to record an ECG at every preventive medical examination.	I

Diagram of atrial fibrillation screening in asymptomatic patients over 65 years using regular ECG monitoring.

Screening for atrial fibrillation in asymptomatic patients (>65 years)	Class
It is recommended to record an ECG using a smart device with ECG (ECG watch, blood pressure monitor with ECG, ECG card) once per month.	I
It is recommended to record an ECG at the physician’s office once per year.	I

Diagram of atrial fibrillation diagnosis in symptomatic patients using ECG recording during symptoms or Holter monitoring.

Screening for atrial fibrillation in symptomatic patients	Class
During symptoms (specific or non-specific), it is recommended to immediately record an ECG using a smart device with ECG (ECG watch, blood pressure monitor with ECG, ECG card).	I
ECG Holter monitoring is recommended: 24-hour or 7-day (preferably).	I

Diagram of atrial fibrillation detection in post-ESUS patients using an implanted ILR recorder and ECG recordings during symptoms.

Screening for atrial fibrillation in patients after ESUS (Embolic Stroke of Undetermined Source)	Class
Implantation of a loop recorder is recommended.	I
During symptoms (specific or non-specific), it is recommended to immediately record an ECG using a smart device with ECG (ECG watch, blood pressure monitor with ECG, ECG card).	I
ECG Holter monitoring (24-hour or 7-day, preferably) may be considered.	IIa