Diagnosing paroxysmal Atrial Fibrillation

It’s a duty doctor morning and you flick through the list of people waiting. You see Stella has requested a call to discuss palpitations. She’s a 76-year-old lady with hypertension who attended A&E yesterday. The discharge summary says she has had a feeling that her heart is fluttering in her chest around once per week for the last month. She went to A&E yesterday because the fluttering went on for two hours and she felt breathless, but by the time she was seen the feeling had passed and her ECG was normal. The A&E registrar has suggested you organise a 24-hour tape and ‘consider’ a Cardiology referral to assess for possible paroxysmal atrial fibrillation (AF). Thanks! 

Diagnosing AF can be challenging. Palpitations are a common symptom, but these are often intermittent and access to extended monitoring is not always easy in primary care. What options are there to detect suspected paroxysmal AF? 

The latest NICE AF guideline encourages clinicians to use a 12-lead ECG to diagnose AF where possible. For people with suspected paroxysmal AF, NICE suggest we should use a type of extended monitor most likely to capture an episode. So, if people are having daily palpitations a 24-hour holter monitor is a good option, but for people with episodes once every few days a different type of monitor, such as a 5-day R-test, may be more appropriate, usually via referral to secondary care. 

Palpitations that occur less than weekly may be particularly difficult to detect. Helpfully, in January 2022, NICE released a new technology appraisal of the AliveCor Kardia device. This device links to people’s smartphones or tablets and can record a rhythm strip ECG. NICE now support the use of AliveCor for detecting paroxysmal AF and it may be particularly useful for those people with infrequent symptoms. Access through the NHS is currently limited, but an increasing number of Clinical Commissioning Groups and Primary Care Networks have been providing devices to reduce referrals so you may well see them in practice soon. Alternatively, An AliveCor Kardia costs around £100 so some patients may be willing to purchase their own or a practice could invest in one to loan to patients. NICE have not yet approved any other wearable devices, such as the AppleWatch, for AF detection. Stella is happy to buy an AliveCor Kardia and you agree she will try to capture an episode of the palpitations on the device. 

A month later you review the results together which confirms Stella has paroxysmal AF. You calculate her CHA₂DS₂VASc score, which is 4 (2 points for age, one sex and a history of hypertension) and she is at low bleeding risk so you discuss starting a direct oral anticoagulant. Remember that if we detect AF, guidelines suggest we still assess their stroke risk based on the CHA₂DS₂VASc score and use this to determine whether we offer anticoagulation and not symptom burden or how the AF was picked up.