What are the recommended investigations for a patient with new-onset atrial fibrillation?

For a patient presenting with new-onset atrial fibrillation (AF), the recommended investigations include several key steps to diagnose the condition, assess risks, and identify underlying causes NICE NG196.

Initial Diagnosis:

• Initially, perform manual pulse palpation to check for an irregular pulse if AF is suspected NICE NG196.


• If an irregular pulse is detected, a 12-lead electrocardiogram (ECG) should be performed to confirm the diagnosis of AF NICE NG196.

Further Diagnostic Investigations for Paroxysmal AF:

• If paroxysmal AF is suspected but undetected by a 12-lead ECG, use a 24-hour ambulatory ECG monitor if asymptomatic episodes are suspected or symptomatic episodes are less than 24 hours apart NICE NG196.


• If symptomatic episodes are more than 24 hours apart, an ambulatory ECG monitor, event recorder, or other ECG technology should be used for a period appropriate to detect AF NICE NG196.

Assessment of Stroke and Bleeding Risks:

• Assess stroke risk using the CHA2DS2-VASc score NICE NG196.


• Assess bleeding risk using the ORBIT bleeding risk score, as evidence shows it has higher accuracy in predicting absolute bleeding risk NICE NG196.


• Monitor and support modification of bleeding risk factors, including uncontrolled hypertension, poor control of international normalised ratio (INR) in patients on vitamin K antagonists, concurrent medication (such as antiplatelets, selective serotonin reuptake inhibitors [SSRIs], and non-steroidal anti-inflammatory drugs [NSAIDs]), harmful alcohol consumption, and reversible causes of anaemia NICE NG196.

Assessment of Cardiac Function and Underlying Heart Disease:

• Perform transthoracic echocardiography (TTE) in people with AF for whom a baseline echocardiogram is important for long-term management, or if a rhythm-control strategy (including cardioversion) is being considered NICE NG196.


• TTE is also indicated if there is a high risk or suspicion of underlying structural or functional heart disease (such as heart failure or a heart murmur) that would influence subsequent management, or if refinement of clinical risk stratification for antithrombotic therapy is needed NICE NG196.


• It is important not to routinely perform TTE solely for further stroke risk stratification if the need for anticoagulation therapy has already been agreed based on appropriate clinical criteria NICE NG196.

Consideration of Underlying Causes:

• Consider investigating for acute, potentially reversible triggers or intercurrent illnesses, such as pneumonia or thyrotoxicosis, as these can cause new-onset AF NICE CKS.