Atrial Fibrillation Cardiovascular ISCEE 26 th October 2010.

Atrial Fibrillation

Cardiovascular ISCEE

26th October 2010

How might AF present in GP?

People with an irregular pulse +/-BreathlessnessPalpitationsChest discomfortSyncope/dizzinessReduced exercise tolerance, malaise or

polyuriaA potential complication of AF such as

stroke, TIA or heart failure

Absence of an abnormal pulse makes a diagnosis of AF unlikely

But its presence does not reliably indicate AF.

Suspect paroxysmal AF if symptoms are episodic and last less than 48 hours.

What do we need to do with them?

ECG to confirm diagnosis

If paroxysmal AF suspected and 12-lead ECG is normal then arrange ambulatory electrocardiography

Bloods

CXR

TFTs – exclude hyperthyroidism

FBC – exclude anaemia

U&Es, Bone Profile, Glucose – exclude electrolyte disturbances which may precipitate AF

LFTs and clotting screen – assess suitability for warfarin

CXR – exclude lung abnormality such as lung cancer, also to detect heart failure

Which ones need to be referred?

Urgently

Patients with:Pulse > 150 bpm and/or low BP (systolic less than

90 mmHg)Loss of consciousness, severe dizziness, ongoing

chest pain or increasing breathlessnessA complication of AF – stroke, TIA, acute HF

Which ones need to be referred?

Outpatients

New onset AF +Young patient (age less than 50 yrs)Suspected paroxysmal AFConcurrent valve diseaseLV systolic dysfunction on echoWolff-Parkinson-White syndrome or a prolonged QT

interval is suspected on the ECGHeart rate is difficult to controlPerson continues to have symptoms despite rate

control treatment

Rhythm vs Rate Rhythm control preferred

treatment for paroxysmal AF and in people with persistent AF with any of the following: Symptomatic < 65 yrs of age First presentation with

lone AF AF secondary to a

treated or corrected precipitant (eg infection)

Congestive heart failure

Rate controlled preferred treatment for permanent AF and in people with persistent AF and any of the following: > 65 yrs age Coronary artery disease Contraindications to

antiarrhythmic drugs Unsuitable for

cardioversion

GP ManagementRate control can be started in primary care

Beta-blockers, rate-limiting Ca-channel blockers, digoxin)

But rhythm control should only be done under specialist supervision Amiodarone, fleicanide, sotalol

Start rate-control anyway if the person does not need admission but Resting pulse >/= 90 bpm Heart rate is fast on exertion, resulting in limited

exercise tolerance

Initial Rate Control Treatment

Beta-blocker or rate limiting Ca-channel blocker (diltiazem or verapamil) unless this is contraindicated

Choice between the 2 groups depends on current medication and co-morbidities

Diltiazem preferred to verapamil because verapamil has a greater negative inotropic effect and interacts with digoxin

Digoxin suitable for older sedentary people in whom rate control is not needed during exercise

Subsequent ManagementReview within 1 week – is the patient tolerating

the drug? Review symptoms, heart rate, BP.

If drug not tolerated, prescribe an alternative. If symptoms not controlled, either increase dose or consider combination treatment.

To control symptoms during normal activities only, use beta-blocker/Ca-blocker with digoxin.

To control symptoms normal activities AND during exercise, use Ca-blocker with digoxin.

Subsequent Management

Do not use a beta-blocker and Ca-blocker to control AF in primary care

If symptoms are not controlled by beta-blocker plus digoxin OR Ca-blocker plus digoxin refer to cardiology

Antithrombotic TreatmentEveryone with AF (paroxysmal, persistent,

permanent) should be offered antithrombotic treatment to reduce their risk of stroke

Offer either aspirin or warfarin without delay after confirming a diagnosis of AF

Choice should be based on person’s risk of stroke

Assess bleeding risk, likelihood of compliance with treatment and preferred options Low risk of stroke – aspirin Moderate risk of stroke – either aspirin or warfarin High risk of stroke – warfarin

Assessing Bleeding RiskFactors that increase risk of bleeding

Age > 75yrsUse of antiplatelet drugsUse of NSAIDsPolypharmacyUncontrolled hypertensionHx of bleeding (bleeding peptic ulcer, cerebral

haemorrhage)Hx of previous poorly controlled anticoagulation

therapy

Assessing Stroke RiskHigh risk

Previous ischaemic stroke / TIA or thromboembolic event

> 75yrs age with risk factors (hypertension, diabetes, coronary artery disease, peripheral artery disease)

Clinical evidence of valve disease or heart failure Impaired LV function on echo

Moderate risk > 65yrs age without risk factors < 75yrs age with risk factors

Low risk < 65yrs age without risk factors

CHADS2Congestive heart failure = 1

Hypertension (or treated hypertension) = 1

Age older than 75 years = 1

Diabetes mellitus = 1

previous Stroke or TIA = 2

Treat with aspirin if total score is 0 or 1

Use warfarin if score is 2 or more

ReferencesNICE 2006 ‘Atrial Fibrillation’

Clinical Knowledge Summaries: ‘Atrial Fibrillation’