Atrial Fibrillation / Flutter

This guideline applies to adults over 18 years of age.

Introduction

Atrial fibrillation (AF) is defined as:

Paroxysmal- less than 7 days

Persistent- between 7 and 30 days

Permanent

Most patients diagnosed with AF can be managed in the community.

Red flag Features

Haemodynamic instability

Pulmonary oedema

Chest pain

Syncope

Key Features of Assessment

Symptoms

• Shortness of breath

• Chest pain

• Symptomatic hypotension

• Symptoms of underlying causes, e.g. fever

• Syncope

• Peripheral oedema

May be asymptomatic

Establish extent of symptoms, including duration and frequency.

If symptoms started less than 48 hours ago and also have red flag symptoms, they may be suitable for cardioversion.

Causes

• Infection

• Dehydration

• Surgery – cardiac or other major surgery

• Cardiac, e.g. myocardial infarction, hypertension or valvular heart disease, ischaemic or non-ischaemic cardiomyopathy

• Respiratory, e.g. acute exacerbation of COPD, sleep apnoea, pulmonary embolism, pneumonia

• Excessive alcohol intake

• Thyrotoxicosis

• Obesity

Examination

• apical and radial pulse.

• BP- standing and lying.

• signs of heart, thyroid, and lung disease.

• signs of dehydration.

• temperature.

Investigations

ECG

Blood tests: FBC, U&Es, LFT, HbA1c, TFTs, Lipids, Bone profile, CRP

Clotting screen – INR and APTT if starting on warfarin (not required for direct oral anticoagulants)

CXR to exclude lung pathology or heart failure.

Community ECHO if appropriate (click here for ECHO guidelines)

All patients with Atrial Fibrillation should have an echocardiogram to exclude structural abnormalities unless:

there has been a previous study and there is no suspicion of change (eg. no new murmurs, no change in clinical status out of keeping with new rhythm and rate)

the presence of structural heart disease will not alter management (eg. elderly patients +/- those with multiple comorbidities who are asymptomatic or who may be best managed in the community and would not wish or are not suitable for invasive management /surgery).

If an Echo is not mentioned in the referral letter, it will be assumed that one has not been requested and therefore Cardiology may request one.

Consider 24 hour tape:

Patients with on-going symptoms despite adequate heart rate at rest/short walk

Symptoms suggestive of additional bradyarrythmia

Patient activity diary is vital to correlate rates with exertion undertaken in addition to symptoms. Remember asymptomatic pauses < 2.8secs daytime and < 4 secs nightime are generally acceptable.

Management

Atrial Fibrillation

Manage modifiable risks:

Alcohol, caffeine, stress, thyroid/lung disease, anaemia, infection

Electrolyte imbalance- particularly low potassium

Optimal heart failure treatment management

Use of medication which increases risk of bleeding, including NSAIDS, SSRI and SNRIs

Stroke risk and anticoagulation therapy decision

Assess stroke risk using the CHA₂DS₂-VASc scoring tool.

Do not use in patients with mitral stenosis or hypertrophic cardiomyopathy as detection of AF in both these groups requires oral anticoagulation therapy, regardless of CHA₂DS₂-VASc.

Be aware that direct oral anticoagulants (DOAC) are not licensed for use in patients with rheumatic heart valve disease, metallic heart valve, or ventricular assist device.

Assess the risk of major bleeding using the ORBIT score calculator:

Use the stroke risk and bleeding risk to determine the need for anticoagulation treatment:

• If low risk, i.e. CHA2DS2-VASc score 0 for men or 1 for women, do not start anticoagulation or aspirin.

• If moderate to high risk, i.e. CHA2DS2-VASc score of 1 or higher in men, or 2 or higher in women, take bleeding risk into account and offer oral anticoagulation.

Direct oral anticoagulants (DOAC) are considered first line unless the patient has rheumatic heart valve disease, metallic heart valve, or ventricular assist device. If intolerant of DOAC or meets the exclusion criteria for DOAC, use warfarin. DOACs including Apixaban, Dabigatran, Edoxaban and Rivaroxaban are suitable options.

Treatment of Atrial Fibrillation

Rate Control

Beta blockers as first line agent eg Bisoprolol 1.25-2.5mg once daily, titrate to achieve resting heart rate of 80-90bpm.

Cardioselective beta blockers are usually tolerated in patients with COPD.

If there are definite contraindications to a B-Blocker try rate slowing calcium channel antagonist in absence of heart failure/normal heart structure on echo.

Diltiazem – the usual starting dose is 60 mg 3 times a day (60 mg twice a day in elderly people). Maintenance doses range from 60 mg to 180 mg 3 times a day.

Verapamil – the usual starting dose is 40 mg 3 times a day. The recommended maximum dose is 120 mg 3 times a day.

Once on an established dose of diltiazem or verapamil, consider switching to a once a day slow-release preparation.

Digoxin – used as monotherapy only in sedentary patients with non-paroxysmal AF who are intolerant or have contraindications to beta blockers or calcium channel blockers. If inadequate ventricular rate control, digoxin can be used as add-on therapy to beta blocker or calcium channel blocker.

Oral loading dose – 1 mg digoxin in divided doses over 24 hours.

Maintenance dose – 125 to 250 microgram once a day, or as per individual requirements. Maintenance dosing at 6.00 pm allows levels to be taken in the morning.

If an elderly patient, use loading dose of 750 microgram digoxin in divided doses over 24 hours. Maintenance dose – 62.5 to 125 microgram once a day.

Digoxin is excreted by the kidneys therefore use with caution in those with renal failure.

Rhythm Control Therapy

• For most patients there is no clear prognostic benefit from rhythm control as opposed to rate control strategy (presuming adequate rate control) and anticoagulant therapy.

The patient should be included in the discussion regarding management strategy and be aware that if at high risk of stroke lifelong oral anticoagulation may be recommended even if sinus rhythm is restored.

Patients with heart failure may benefit from maintenance of sinus rhythm but overall there is no clear prognostic benefit from rhythm control, assuming adequate rate control.

Cardioversion can control rhythm but has a high recurrence rate of around 50% at 12 months and may have complications.

Other antiarrhythmics are only recommended for use in the community if advised by Cardiologist due to significant side effects.

If patients revert to sinus rhythm during treatment patients are manage as for paroxysmal atrial fibrillation.

Manage paroxysmal atrial fibrillation

• Treat each episode and any reversible causes above.

• Calculate the CHA2DS2-VASc score and offer oral anticoagulation.

• If necessary, start rate controlling agents (beta blocker first line).

If ongoing symptoms, refer to Cardiology for ablation or other treatments, especially if few co morbidities.

Only consider "pill in the pocket" anti arrhythmics, e.g. flecainide acetate following Cardiology review due to potentially serious side effects.

Manage risk factors: weight loss, hypertension, diabetes, treat sleep apnoea.

Advise other lifestyle management, e.g. alcohol reduction, exercise, and smoking cessation.

Referral

Consider admission if:

New onset Atrial fibrillation/flutter within the last 48 hours associated with haemodynamic instability(e.g. pulse of >150 and/or systolic BP < 90mmHg)

Atrial Fibrillation/flutter associated with syncope, chest pain, heart failure and/or shortness of breath

New onset AF/flutter within the last 48 hours in patients who are haemodynamically stable where cardioversion is being considered, please discuss with the Acute GP service.

The majority of patients diagnosed with atrial fibrillation can be managed in the community.

Consider referral for rate control strategy if:

On-going symptoms or inadequate rate control despite community medical management (aim for resting pulse <110bpm, or < 80bpm in those who remain symptomatic)

The patient has structural heart disease

Symptomatic confirmed bradyarrhythmia or asymptomatic daytime pauses > 2.8 secs or nocturnal > 4secs

Consider referral for rhythm control strategy if:

On-going limiting symptoms despite adequate rate control

Patients who are younger (generally < 65years)

Patients have had either self-limiting or a corrected trigger e.g. infection, throtoxicosis, PE, Surgery but have persistent AF

The patient has heart failure caused or worsened by AF.

The ECG in sinus rhythm suggests an electrophysiological disorder e.g. short PR interval/delta wave.

Considering Amiodarone

Considering “pill in pocket” anti-arrhythmic medications (eg Flecanide).

Investigations required for referral

ECG confirming rhythm and rate.