• Confirm the diagnosis of atrial fibrillation (AF) by performing electrocardiography.
• Determine the type of AF (paroxysmal, persistent, or permanent) based on the person's history or, if paroxysmal AF is suspected, by organizing 24-hour ambulatory electrocardiography.
• Determine whether admission to hospital or referral to a cardiologist is required (such as for people with paroxysmal AF, or persistent AF where rhythm control is the preferred treatment).
• If referral is not required, assess the person's risk of stroke to determine appropriate antithrombotic treatment and consider starting rate control treatment.
• Regularly review people with established AF to measure their pulse rate and blood pressure, reassess their risk of stroke, and exclude complications of AF and drug treatment.

• Admit (or refer) for urgent assessment and intervention if the person has any of the following:
• A rapid pulse (greater than 150 beats per minute) and/or low blood pressure (systolic blood pressure less than 90 mmHg).
• Loss of consciousness, severe dizziness, ongoing chest pain, or increasing breathlessness.
• A complication of atrial fibrillation (AF), such as stroke, transient ischaemic attack, or acute heart failure.
• Refer people with new-onset AF to a specialist in cardiology if:
• The person is young (for example less than 50 years of age).
• Paroxysmal AF is suspected.
• Rhythm control is the preferred treatment, or there is uncertainty regarding this (see Rate or rhythm control).
• Drug treatments for rate control or antithrombotic treatment that can be used in primary care are contraindicated.
• The person is found to have valve disease or left ventricular systolic dysfunction on echocardiography.
• Wolff–Parkinson–White syndrome or a prolonged QT interval is suspected on the electrocardiogram.
• Heart rate is difficult to control, or the person continues to have symptoms despite rate-control treatment (see Management after starting rate-control treatment).

The National Institute for Health and Clinical Excellence (NICE) makes no specific recommendations regarding referring people with atrial fibrillation (AF) from primary to secondary care. The following recommendations are inferred from the NICE guidance [NICE, 2006] or are based on expert opinion [NHS Scotland, 2005].

Admission

• Most people presenting with AF are not haemodynamically compromised. If the person is compromised, admission to hospital is needed for urgent intervention to prevent further deterioration.
• NICE states that the following people in AF are those at highest risk from haemodynamic instability:
• People with a ventricular rate greater than 150 beats per minute.
• Those with ongoing chest pain.
• After reviewing the evidence (three small studies), NICE concluded that rate-control drugs (such as beta-blockers and rate-limiting calcium-channel blockers) and pharmacological and electrical cardioversion are effective treatment options for the management of people presenting with haemodynamic instability.
• Usually, electrical cardioversion is the treatment of choice for people with haemodynamic instability, and amiodarone is only used when there is an unacceptable delay to cardioversion.

Referral

• Type of AF
• It may be difficult to categorize AF. For example, different types of AF are not mutually exclusive, and the person may have episodes of paroxysmal AF and occasional persistent AF. Specialist input may be needed to categorize the person on their most frequent presentation [Fuster et al, 2006a].
• Paroxysmal AF
• Paroxysmal AF requires antiarrhythmic drugs that are not usually started in primary care (such as amiodarone or sotalol).
• Advice given in the British National Formulary is that class I and III drugs (such as flecainide) should usually only be started by a specialist [BNF 57, 2009].
• Deciding between rhythm or rate control
• Some people with persistent AF will satisfy criteria for both rate and rhythm control (for example, older than 65 years of age but also symptomatic); therefore, specialists may consider additional investigations (echocardiography) and take into account the person's comorbidities before deciding on the most appropriate treatment.
• Failed primary care treatment, electrocardiogram abnormality, or cardiac dysfunction
• If the person with AF has persistent symptoms despite maximum treatment given in primary care, a specialist may consider the use of drugs that are not routinely started in primary care (such as amiodarone or sotalol).
• In addition to drug treatment, a specialist may consider further interventions depending on the person's age, severity of symptoms, type of AF, and presence of cardiac dysfunction (for example such interventions as pulmonary vein isolation, pacemaker therapy, arrhythmia surgery, catheter ablation, or use of atrial defibrillators).

• An electrocardiogram should already have been done to confirm the diagnosis of atrial fibrillation. An electrocardiogram may also indicate a possible underlying cause (such as old myocardial infarction, left ventricular hypertrophy, or a pre-excitation syndrome).
• Do the following tests:
• Thyroid function tests (to exclude hyperthyroidism).
• Full blood count (to exclude anaemia).
• Blood urea and electrolytes, calcium, and glucose measurement (to exclude electrolyte disturbances, which may precipitate atrial fibrillation).
• Liver function tests and a clotting screen (to assess suitability for warfarin).
• Chest radiography (to assess a suspected lung abnormality, such as lung cancer; this test may also help to detect heart failure).
• For people not being referred to a cardiologist, consider organizing transthoracic echocardiography if:
• There is a high risk or a suspicion of underlying heart disease (for example signs of heart failure or a cardiac murmur).
• Information on cardiac structure or function is needed to make a decision about starting antithrombotic treatment.
• Most decisions about starting antithrombotic treatment should be based on clinical judgement. Do not routinely organize echocardiography solely for risk stratification if the person meets the clinical criteria to start warfarin.

These recommendations are based on the National Institute for Health and Clinical Excellence (NICE) guideline Atrial fibrillation: National clinical guideline for management in primary and secondary care [National Collaborating Centre for Chronic Conditions, 2006] and published expert opinion [MeReC, 2002; NHS Scotland, 2005; Fuster et al, 2006a; ICSI, 2008].

• NICE does not give specific recommendations on when to refer for echocardiography in those people who present to primary care with atrial fibrillation (AF).
• After reviewing good-quality evidence (29 studies) on the ability of echocardiographic findings to predict outcomes in AF (such as recurrence of AF after cardioversion, stroke, or vascular death), NICE gave general advice on which people should undergo echocardiography.
• NICE states that the decision to start appropriate antithrombotic treatment can be made clinically. However, the risk may be unclear in some people (such as those with suspected left ventricular dysfunction without overt heart failure), in which case echocardiography may be useful in refining their risk for stroke.

• Rate control can be started in primary care, but rhythm control should only be started following specialist assessment.
• Rate control is the preferred treatment for permanent atrial fibrillation (AF) and in people with persistent AF and any of the following:
• More than 65 years of age.
• With coronary artery disease.
• With contraindications to antiarrhythmic drugs.
• Unsuitable for cardioversion.
• Rhythm control is the preferred treatment for paroxysmal AF and in people with persistent AF and any of the following:
• Symptomatic.
• 65 years of age or less.
• Presenting for the first time with lone AF.
• Presenting with AF secondary to a treated or corrected precipitant (such as infection).
• With congestive heart failure.
• If there is uncertainty about which option is best (for example the person may be older than 65 years of age with lone AF), seek specialist advice.

• Rate control involves the use of drugs to slow the ventricular heart rate, in an attempt to minimize symptoms and associated morbidity of atrial fibrillation (AF). Rate control will not stop the atria from fibrillating.
• Rhythm control involves the use of drugs to maintain normal sinus rhythm once AF has terminated (spontaneously or after electrical or pharmacological cardioversion). Rhythm control is often needed long term to help prevent recurrence of AF.
• Cardioversion is unsuitable for people with:
• Contraindications to anticoagulation.
• Structural heart disease (for example a large left atrium greater than 5.5 cm or mitral stenosis) that makes it unlikely that sinus rhythm would be maintained following successful cardioversion. 
• A long duration of AF (usually greater than 12 months).
• A history of multiple failed attempts at cardioversion and/or relapses, even with concomitant use of antiarrhythmic drugs or non-pharmacological approaches.
• An ongoing but reversible cause of AF, until the precipitant has been effectively treated (such as thyrotoxicosis).

These recommendations are based on the National Institute for Health and Clinical Excellence (NICE) guideline Atrial fibrillation: national clinical guideline for management in primary and secondary care [National Collaborating Centre for Chronic Conditions, 2006].

• After reviewing the evidence (five randomized controlled trials and one meta-analysis) comparing rate control with rhythm control on different outcomes, NICE concluded that overall there is no difference between rhythm control and rate control in terms of mortality or quality of life.
• NICE states that rate control is the preferred treatment in people with permanent AF (as by definition rhythm control has been tried and failed, or is not an option), and in people with persistent AF who are older than 65 years of age, have evidence of coronary heart disease, or have no evidence of heart failure, as there is some evidence that rate control may be superior in these groups.
• In one study, there was a significant difference in favour of rate control in terms of all-cause mortality in people older than 65 years of age and in people with coronary artery disease.
• In three studies, rhythm control compared with rate control resulted in a higher rate of adverse effects and hospital admissions and a higher incidence of arrhythmias in people with recurrent AF.
• In one study, rhythm control was associated with a lower incidence of all-cause mortality in people with heart failure.
• However, CKS found a subsequent prospective, open-labelled trial (n = 1376) with 2 years of follow-up which suggests that in people with AF and symptoms of heart failure, rhythm control and rate control may result in similar cardiovascular outcomes [Roy et al, 2008].

• Rate-control treatments (beta-blockers, rate-limiting calcium-channel blockers, and digoxin) can be started in primary care, but rhythm-control treatments (such as amiodarone, flecainide, and sotalol) should only be started on specialist advice.
• Consider starting a rate-control drug if the person does not require admission, regardless of whether they are to be managed in primary care or have been referred to a specialist for consideration of rhythm control, if:
• The resting heart rate is 90 beats per minute or more, or
• The heart rate is fast on exertion, resulting in limited exercise tolerance.

Heart rate control

• The National Institute for Health and Clinical Excellence (NICE) recommends that resting heart rate should be controlled to less than 90 beats per minute, and that heart rate on exercise should be controlled to less than 110 beats per minute in people who are inactive or 200 beats per minute minus their age in active people [NICE, 2006].
• A consensus statement from the Royal College of Physicians of Edinburgh suggests a target resting heart rate of less than 90 beats per minute and less than 180 beats per minute during exercise [RCGP, 1999].
• An international guideline states that criteria for rate control vary with age and suggests that ventricular rate should be controlled between 60–80 beats per minute at rest and between 90–115 beats per minute during moderate exercise [Fuster et al, 2006b].
• In clinical practice, the target heart rate during exercise may need to be adjusted depending on the level of exercise the person can manage. For example, a rate of 170 beats per minute is inadequate rate control if the person has only walked up the corridor.

These recommendations are based on the National Institute for Health and Clinical Excellence (NICE) guideline Atrial fibrillation: national clinical guideline for management in primary and secondary care [National Collaborating Centre for Chronic Conditions, 2006].

• The aim of rate control is to minimize symptoms associated with excessive heart rate (such as breathlessness) and prevent tachycardia-associated cardiomyopathy [Fuster et al, 2006b].
• Adequate rate control has not been well studied with respect to quality of life, or symptoms or development of cardiomyopathy, and no standard method for assessment of rate control has been established to guide management.
• CKS has outlined the suggested rate control targets from several guideline groups [RCGP, 1999; Fuster et al, 2006a; National Collaborating Centre for Chronic Conditions, 2006].

• Offer a beta-blocker or rate-limiting calcium-channel blocker (diltiazem or verapamil), unless this is contraindicated.
• The choice between beta-blocker and calcium-channel blocker will depend on the person's current medication and comorbidities.
• Diltiazem (off-licensed use for atrial fibrillation) is preferred to verapamil because verapamil has a greater negative inotropic effect on the heart and interacts with digoxin.
• For further information, see the prescribing sections on beta-blockers and calcium-channel blockers.
• If the person has a sedentary lifestyle, digoxin is an alternative option.
• Digoxin is only adequate for older, sedentary people in whom rate control is not needed during exercise.
• For further information, see the prescribing section on digoxin.

These recommendations are based on the National Institute for Health and Clinical Excellence (NICE) guideline Atrial fibrillation: national clinical guideline for management in primary and secondary care [National Collaborating Centre for Chronic Conditions, 2006].

After reviewing 12 small randomized or serial crossover trials comparing beta-blockers and calcium-channel blockers for atrial fibrillation (AF), NICE concluded that:

• Both calcium-channel blockers and beta-blockers are more effective than digoxin in controlling heart rate at high levels of physical exertion, but there is no difference during normal daily activities.
• There is no significant difference between calcium-channel blockers and beta-blockers in terms of heart rate control.

Beta-blockers versus calcium-channel blockers

• One crossover study found no difference between diltiazem and atenolol in terms of heart rate over 24 hours or during exercise.
• A second crossover study found no difference between verapamil and atenolol in heart rate at rest or after exercise.

Calcium-channel blockers versus digoxin

• Seven studies found no difference in heart rate between verapamil or diltiazem and digoxin, either at rest or during normal daily activity.
• Seven studies found that verapamil or diltiazem resulted in a lower heart rate during exercise compared with digoxin.

Beta-blockers versus digoxin

• Three studies found no difference in average heart rate between digoxin and beta-blockers while at rest or during normal daily activity.
• Atenolol and labetalol controlled heart rate during exercise more effectively than digoxin.
• One study found that atenolol significantly reduced heart rate compared with digoxin both at rest and after exercise.

• Within 1 week, check whether the person is tolerating the drug and review symptoms, heart rate, and blood pressure.
• If the person cannot tolerate the drug, prescribe an alternative (see Initial drug treatment for rate control).
• If the person's symptoms and/or heart rate are not controlled:
• If they are not taking the maximum drug dose, consider increasing the dose to control symptoms, or
• If they are taking the maximum drug dose, consider combining drug treatments.
• To control symptoms during normal activities only, use a beta-blocker or calcium-channel blocker (diltiazem or verapamil) with digoxin.
• To control symptoms during normal activities and during exercise, use a calcium-channel blocker (diltiazem or verapamil) with digoxin. If the person is already taking a beta-blocker, it may be more practical to add in digoxin first, and if symptoms are still not controlled, then switch the beta-blocker with a calcium-channel blocker.
• Do not use a combination of a beta-blocker and a rate-limiting calcium-channel blocker to control atrial fibrillation in primary care.
• If symptoms are not controlled with a beta-blocker plus digoxin or a calcium-channel blocker plus digoxin, refer to a specialist in cardiology.
• For detailed prescribing information, see the prescribing sections on beta-blockers, calcium-channel blockers, and digoxin.

Heart rate control

• The National Institute for Health and Clinical Excellence (NICE) recommends that resting heart rate should be controlled to less than 90 beats per minute, and that heart rate on exercise should be controlled to less than 110 beats per minute in people who are inactive or 200 beats per minute minus their age in active people [NICE, 2006].
• A consensus statement from the Royal College of Physicians of Edinburgh suggests a target resting heart rate of less than 90 beats per minute and less than 180 beats per minute during exercise [RCGP, 1999].
• An international guideline states that criteria for rate control vary with age and suggests that ventricular rate should be controlled between 60–80 beats per minute at rest and between 90–115 beats per minute during moderate exercise [Fuster et al, 2006b].
• In clinical practice, the target heart rate during exercise may need to be adjusted depending on the level of exercise the person can manage. For example, a rate of 170 beats per minute is inadequate rate control if the person has only walked up the corridor.

These recommendations are based on the National Institute for Health and Clinical Excellence (NICE) guideline Atrial fibrillation: national clinical guideline for management in primary and secondary care [National Collaborating Centre for Chronic Conditions, 2006]. Rate control is not always achieved with a single drug, and combination drug treatment may be required.

Beta-blocker with digoxin versus beta-blocker alone

• One crossover study with 12 participants found that atenolol used in combination with digoxin resulted in a lower heart rate over 24 hours than that achieved with atenolol alone [Farshi et al, 1999]. This study found no statistically significant difference in heart rate during periods of exercise.

Calcium-channel blocker with digoxin versus calcium-channel blocker alone

• Four crossover studies (with about 15 participants in each study) found that diltiazem or verapamil used in combination with digoxin was more effective in controlling heart rate over 24 hours, as well as during periods of exercise, than either diltiazem or verapamil alone.

Combination of beta-blocker and calcium-channel blocker

• NICE does not recommend the use of a beta-blocker and rate-limiting calcium-channel blocker for atrial fibrillation in primary care owing to the increased risk of bradycardia with this combination.

Referral

• If digoxin with a beta-blocker, or digoxin with a calcium-channel blocker, is ineffective or not tolerated, a specialist may consider the use of amiodarone, or diltiazem with a beta-blocker, to control atrial fibrillation. Alternatively, a non-pharmacological approach (mainly atrioventricular node ablation coupled with pacing) might be considered.

• All people with atrial fibrillation (whether paroxysmal, persistent, or permanent) should be offered antithrombotic treatment to reduce their risk of stroke.
• Offer either aspirin or warfarin, without delay, after confirming a diagnosis of atrial fibrillation.
• The choice of either aspirin or warfarin should be based on the person's risk of stroke — see Which antithrombotic treatment.

These recommendations are based on the National Institute for Health and Clinical Excellence (NICE) guideline Atrial fibrillation: national clinical guideline for management in primary and secondary care [National Collaborating Centre for Chronic Conditions, 2006].

Antithrombotic treatment for all people with atrial fibrillation (AF)

• AF is an independent risk factor of stroke; the annual risk for stroke is five to six times higher in people with AF than in people in sinus rhythm.
• Strokes that occur in association with AF are more likely to result in greater mortality, morbidity, and disability and longer hospital stays than strokes that occur in people without AF.
• Good evidence indicates that antithrombotic treatment reduces the risk of stroke in all people with AF.

Starting antithrombotic treatment after a diagnosis of AF

• Provided that the person has no contraindications to antithrombotic treatment (such as uncontrolled hypertension), NICE states that treatment should be started as soon as possible after a diagnosis of AF to minimize the risk of stroke.
• Stroke risk stratification can be easily performed in primary care on the basis of clinical criteria; therefore, a primary healthcare professional should not delay antithrombotic treatment by waiting for a cardiology opinion.

Antithrombotic treatment compared with placebo or no treatment

• After reviewing the evidence, NICE concluded that treatment with warfarin or an antiplatelet drug is more effective than placebo or no treatment in the prevention of cardioembolic stroke in people with AF.
• Two systematic reviews found evidence that aspirin was associated with a statistically non-significant reduction in stroke risk. However, a statistically significant risk reduction in a combined outcome of stroke, myocardial infarction, or vascular death was seen.
• Three systematic reviews found evidence that compared with placebo, warfarin significantly reduced the risk of stroke by two-thirds in people with AF. Compared with placebo, warfarin was associated with an increased risk of extracranial bleeding, but there was no increased incidence of intracranial bleeding.

• Treatment decisions should be made on an individual basis; the person's bleeding risk, likelihood of compliance with treatment, and preferred options should always be fully assessed before starting treatment.
• Offer people with atrial fibrillation (AF):
• At low risk of stroke — aspirin.
• At high risk of stroke — warfarin.
• At moderate risk of stroke — either aspirin or warfarin.
• If uncertain about stroke risk, start aspirin whilst awaiting specialist assessment.
• CKS do not recommend the use of clopidogrel or a combination of aspirin and clopidogrel for AF in primary care.
• Risk factors have a cumulative effect on stroke risk; this should be considered when discussing treatment options. For example, if the person is in the moderate stroke risk category but has more than one risk factor for stroke (that is, more than one of hypertension, diabetes, coronary artery disease, or peripheral artery disease), there may be a stronger case for choosing warfarin over aspirin.
• For detailed information on the use of aspirin and warfarin in AF, including contraindications, starting doses and titration, monitoring, and adverse effects, see the CKS topics on Antiplatelet treatment and Anticoagulation - oral.

• The National Institute for Health and Clinical Excellence does not state that a formal bleeding risk assessment is necessary before starting antithrombotic treatment, but it provides a list of risk factors that increase the risk of bleeding with warfarin:
• More than 75 years of age.
• Use of antiplatelet drugs (such as aspirin or clopidogrel).
• Use of nonsteroidal anti-inflammatory drugs.
• Use of multiple other drugs (polypharmacy).
• Uncontrolled hypertension.
• History of bleeding (for example bleeding peptic ulcer or cerebral haemorrhage).
• History of previously poorly controlled anticoagulation therapy.
• For more information on starting warfarin, see the CKS topic on Anticoagulation - oral.

These recommendations are based on the National Institute for Health and Clinical Excellence (NICE) guideline Atrial fibrillation: national clinical guideline for management in primary and secondary care [National Collaborating Centre for Chronic Conditions, 2006].

Warfarin versus aspirin

• Good evidence indicates that warfarin is more effective than aspirin for preventing stroke or vascular events in people with atrial fibrillation (AF) but is associated with a higher risk of intracranial and extracranial bleeding.
• For people without prior stroke or transient ischaemic attack (TIA), a Cochrane systematic review (eight randomized controlled trials [RCTs]) found that warfarin reduced the risk of stroke and other major vascular events in people with AF by about one-third compared with antiplatelets [Aguilar et al, 2007].
• For people who have had a stroke or TIA, a Cochrane systematic review (two RCTs) found that warfarin reduced the risk of stroke by a half, and the risk of any vascular event by one-third, compared with antiplatelets [Saxena and Koudstaal, 2004b].
• For people 75 years of age or older, an open-label RCT (973 participants) found that warfarin (target international normalized ratio 2.0–3.0) reduced the risk of stroke by half and the risk of vascular events by two-thirds, compared with aspirin 75 mg daily [Mant et al, 2007b].

Clopidogrel alone

• NICE do not recommend the use of clopidogrel in AF. Clopidogrel is not licenced for AF and there is no trial evidence to support its use. However, a number of CKS expert reviewers do state that they would use clopidogrel as an alternative treatment option in people with a true aspirin allergy.

Combining antithrombotic treatment

• NICE states that if warfarin is offered, aspirin should not be taken concomitantly to prevent stroke, as it provides no additional benefit and may increase the risk of bleeding.
• CKS does not recommend the use of aspirin plus clopidogrel in primary care to reduce the risk of stroke in AF.
• There is evidence that warfarin significantly reduces the risk of stroke, myocardial infarction, and vascular events compared with clopidogrel plus aspirin [Connolly et al, 2006]. Warfarin did not increase the risk of bleeding compared with clopidogrel plus aspirin.
• A recently published trial found evidence that combined treatment with clopidogrel plus aspirin reduces the risk of major vascular events compared with aspirin alone [ACTIVE Investigators et al, 2009]. However, this trial also found evidence that combined treatment with clopidogrel plus aspirin was associated with a two-fold increased risk of major bleeding.

• Assess the person's risk of stroke using the following criteria:
• High risk of stroke
• Previous ischaemic stroke/transient ischaemic attack or thromboembolic event.
• 75 years of age or more with risk factors (hypertension, diabetes, coronary artery disease, peripheral artery disease).
• Clinical evidence of valve disease or heart failure, or impaired left ventricular function on echocardiography.
• Moderate risk of stroke
• 65 years of age or more without risk factors.
• Less than 75 years of age with risk factors.
• Low risk of stroke
• Less than 65 years of age without risk factors.
• The CHADS₂ tool can also be used to calculate the risk of stroke (see clarification for more details).
• Risk factors have a cumulative effect on stroke risk; this should be considered when discussing treatment options (see Which antithrombotic treatment).
• If uncertain about the person's risk of stroke, consider referral to a cardiologist.

• Another method of stroke risk stratification is the CHADS₂ criteria. The acronym CHADS₂ is derived from individual stroke risk factors. Adding together the points allocated to each risk factor yields the total CHADS₂ score:
• Congestive heart failure = 1.
• Hypertension (or treated hypertension) = 1.
• Age older than 75 years = 1.
• Diabetes mellitus = 1.
• Previous stroke or transient ischaemic attack = 2.
• The following treatment is recommended:
• Aspirin if the total score is 0 (low risk) or 1 (moderate risk).
• Warfarin (if there are no contraindications) if the total score is 2 or more.

These recommendations are based on the National Institute for Health and Clinical Excellence (NICE) guideline Atrial fibrillation: national clinical guideline for management in primary and secondary care [National Collaborating Centre for Chronic Conditions, 2006].

• On the basis of cohort studies, the Scottish Intercollegiate Guidelines Network published guidance showing the risk of stroke in people with atrial fibrillation (AF) considered to be at low, moderate, and high risk. For more information, see the antithrombotic therapy section in the SIGN guidance [SIGN, 1999].

Risk factors for stroke

• A systematic review (search date October 2005, seven studies) suggests that prior stroke or transient ischaemic attack (TIA), advancing age, hypertension, and diabetes are independent risk factors for stroke in people with AF [Stroke Risk in Atrial Fibrillation Working Group, 2007].
• Absolute stroke rates were in the range 6–9% per year for prior stroke or TIA, 1.5% to 3% per year for history of hypertension, 1.5–3% per year for age more than 75 years, and 2.0–3.5% per year for diabetes.
• In the systematic review, evidence for heart failure and coronary artery disease as independent risk factors for stroke is inconclusive. However, NICE includes heart failure and vascular disease as independent risk factors for stroke on the basis that left ventricular dysfunction is associated with an increased risk of stroke. Atherosclerotic vascular disease is also a risk factor for stroke, with a poor prognosis when associated with AF [Goto et al, 2008].

CHADS₂ for stroke risk

• The CHADS₂ score was designed to provide a simple approach to assessing stroke risk in primary care. The score was validated by a study on people 65–95 years of age with nonrheumatic AF who were not prescribed warfarin [Gage et al, 2004].
• The CHADS₂ criteria have been assessed against risk factors refined to form the NICE criteria, and both were found to be similar for predicting event rates in a cohort prospectively followed up for stroke and vascular events [Lip et al, 2006].

• Check for ongoing symptoms (at rest or with exercise) and assess heart rate.
• If the person is taking rate-control treatment and has persistent symptoms or a fast heart rate, consider increasing the drug dose (if they are not taking the maximum dose), combining drug treatments (if this has not already been done), or referring to a cardiologist.
• If the person is taking rhythm-control treatment and has recurring or persistent symptoms, refer back to a cardiologist for further assessment (for example for development of persistent atrial fibrillation [AF] or failed rhythm-control treatment).
• Assess stroke and cardiovascular disease (CVD) risk.
• If the person is not taking warfarin, reassess risk of stroke if they develop diabetes, hypertension, or cardiovascular disease, or when they reach 65 and 75 years of age.
• If the person is taking warfarin, reassess risk of bleeding (such as risk of falling).
• For information on how to assess CVD risk, see the CKS topic on CVD risk assessment and management.
• Check for complications of AF and assess blood pressure.
• Identify and manage existing heart failure or hypertension — see the CKS topics on Heart failure - chronic and Hypertension - not diabetic.
• Review the person's medication.
• Check compliance, and identify and manage drug interactions and complications (such as dyspepsia with aspirin).
• Give advice on known drug interactions and which drugs should be avoided with aspirin or warfarin (see Prescribing information).
• Provide information on AF.
• Provide written information (if this has not already been given).
• Explain when to seek further medical advice (such as worsening symptoms).
• For more information on patient education and support groups, see www.atrialfibrillation.org.uk.

Heart rate control

• The National Institute for Health and Clinical Excellence recommends that resting heart rate should be controlled to less than 90 beats per minute, and that heart rate on exercise should be controlled to less than 110 beats per minute in people who are inactive or 200 beats per minute minus their age in active people [NICE, 2006].
• A consensus statement from the Royal College of Physicians of Edinburgh suggests a target resting heart rate of less than 90 beats per minute and less than 180 beats per minute during exercise [RCGP, 1999].
• An international guideline states that criteria for rate control vary with age and suggests that ventricular rate should be controlled between 60 and 80 beats per minute at rest and between 90 and 115 beats per minute during moderate exercise [Fuster et al, 2006b].
• In clinical practice, the target heart rate during exercise may need to be adjusted depending on the level of exercise the person can manage. For example, a rate of 170 beats per minute is inadequate rate control if the person has only walked up the corridor.

• These recommendations are based in part on the National Institute for Health and Clinical Excellence (NICE) guideline Atrial fibrillation: national clinical guideline for management in primary and secondary care [National Collaborating Centre for Chronic Conditions, 2006], the Institute for Clinical Systems Improvement health care guideline Atrial fibrillation [ICSI, 2008], and a guideline produced jointly by US and European specialist groups [Fuster et al, 2006a].

• Refer all people with paroxysmal atrial fibrillation (AF) to a cardiologist for management.
• While the person is waiting to see a specialist:
• Start either aspirin or warfarin (if they are not contraindicated), to reduce the person's risk of stroke.
• The choice of antithrombotic treatment should be based on the person's risk of stroke and not on the frequency or duration of paroxysms of AF.
• For further information, see Which antithrombotic treatment.
• If the person is having frequent, symptomatic paroxysms but does not require admission, consider starting a beta-blocker (unless this is contraindicated).
• Seek advice if uncertain whether to start drug treatment.
• For further information, see the prescribing section on beta-blockers.
• If a specialist initiates rhythm-control treatment, initial follow up and drug monitoring will be carried out by the specialist. However, primary healthcare professionals will be involved in the longer-term follow up (for example, monitoring of drugs and identifying complications of AF).

These recommendations are based on the National Institute for Health and Clinical Excellence (NICE) guideline Atrial fibrillation: national clinical guideline for management in primary and secondary care [National Collaborating Centre for Chronic Conditions, 2006].

• The aims of treating paroxysmal atrial fibrillation (AF) are to prevent paroxysms of AF and maintain sinus rhythm, to control heart rate during paroxysms of AF, and to prevent complications (such as stroke).
• Drugs used to manage paroxysmal AF (such as amiodarone or sotalol) are not usually started in primary care; therefore, referral to a cardiologist is necessary.

Antithrombotic treatment

• Controlling the symptoms of paroxysmal AF does not necessarily mean abolition of the AF (asymptomatic episodes may still occur). Evidence indicates that people with paroxysmal AF are at the same risk of stroke as people with persistent or permanent AF and should be assessed in the same way as people with persistent AF.
• After reviewing limited evidence (subgroup analyses of two meta-analyses), NICE concluded that the efficacy of antithrombotic treatment in reducing the risk of ischaemic stroke is similar in people with paroxysmal AF and non-paroxysmal AF. The incidence of major bleeding was also similar between both groups.
• One meta-analysis (six randomized trials, 4052 participants) found that in people treated with aspirin, the incidence of stroke was similar in people with paroxysmal AF and non-paroxysmal AF [van Walraven et al, 2002].
• One meta-analysis (29 trials, 28,044 participants) found warfarin to be associated with a reduced incidence of ischaemic stroke compared with aspirin (1.5% compared to 4.7% respectively, p < 0.05) in people with AF [Hart et al, 2007]. These results were similar for people with paroxysmal AF and non-paroxysmal AF.

Rhythm-control treatment

• NICE recommends starting treatment with a standard beta-blocker to control frequent paroxysms of AF, especially if paroxysms are associated with symptoms. Therefore, starting a beta-blocker in primary care will help reduce the number of paroxysms, help with symptoms, and possibly maintain sinus rhythm while awaiting specialist assessment.

Follow up

• The specialist will usually follow up the person to assess whether they are still continuing to have paroxysms of AF and determine whether further treatment is necessary.

Persistent atrial fibrillation (AF)

• Cardioversion is performed as part of a rhythm-control strategy in people with persistent AF and, if successful, will restore sinus rhythm.
• Cardioversion can be carried out either with the use of drugs (pharmacological cardioversion) or electrical shock (electrical cardioversion).
• Not all attempts at cardioversion are successful, and at 1 year after cardioversion, approximately 50% of people will be back in AF.

Paroxysmal AF

• If the person has infrequent paroxysms and few symptoms, the specialist may offer:
• A no-drug treatment strategy, or
• A pill-in-the-pocket strategy (self-administration of an antiarrhythmic drug if an episode of AF occurs).
• If the person has symptomatic paroxysms, a standard beta-blocker (such as atenolol) will usually be offered first-line:
• If a standard beta-blocker does not adequately control paroxysms, sotalol may be used, or if there is no structural heart disease or coronary artery disease, a class Ic antiarrhythmic drug (such as flecainide or propafenone) may be tried.
• If none of these are effective, the specialist may use amiodarone, or refer for non-pharmacological intervention (such as surgical ablation and pacemaker).

Failed treatment, lone AF, or an electrophysiological disorder causing AF

• In people in whom pharmacological treatment has failed, those with lone AF, and those with evidence of an underlying electrophysiological disorder (for example, Wolff–Parkinson–White syndrome), a specialist may consider such interventions as pulmonary vein isolation, pacemaker therapy, arrhythmia surgery, catheter ablation, or atrial defibrillators [Fuster et al, 2006b; ICSI, 2008].

[National Collaborating Centre for Chronic Conditions, 2006]

• Advise the person that it is their responsibility to inform the Driver and Vehicle Licensing Agency (DVLA) of any condition that may affect their ability to drive.
• The DVLA's medical rules regarding atrial fibrillation are:
• For group 1 entitlement (cars, motorcycles):
• Driving must cease if the arrhythmia has caused or is likely to cause incapacity.
• Driving may be permitted when the underlying cause has been identified and controlled for at least 4 weeks
• The DVLA need not be notified unless there are distracting or disabling symptoms.
• For group 2 entitlement (lorries, buses):
• Disqualified from driving if the arrhythmia has caused or is likely to cause incapacity.
• Driving may be permitted when the arrhythmia is controlled for at least 3 months; the left ventricular ejection fraction is equal to or greater than 0.4; there is no other disqualifying condition.
• The person should check with their insurer that they are still covered for driving.
• The latest information from the DVLA regarding medical fitness to drive can be obtained at www.dvla.gov.uk/medical/ataglance.

• This information on medical rules is from the Driver and Vehicle Licensing Agency's guidance for medical practitioners, At a glance guide to the current medical standards of fitness to drive [DVLA, 2010].

In depth

• Advise the person that there are no flying restrictions provided they have stable atrial fibrillation which has not recently worsened or become more symptomatic.

• These recommendations are based on the British Heart Foundation Factfile: Fitness to fly for passengers with cardiovascular disease, which is based on the British Cardiovascular Society Working Group's expert guidance [BHF, 2010].

In depth