Atrial Fibrillation
Steve McGlynn
Specialist Principal Pharmacist (Cardiology),
Greater Glasgow and Clyde
Honorary Clinical Lecture,
University of Strathclyde
Some types of arrhythmia


Supraventricular
 Sinus Nodal
 Sinus bradycardia
 Sinus tachycardia
 Sinus arrhythmia
 Atrial
 Atrial tachycardia
 Atrial flutter
 Atrial fibrillation
 AV Nodal
 AVNSVT
 Heart blocks
 Junctional
Ventricular
 Escape rhythms
 Ventricular tachycardia
 Ventricular fibrillation
Atrial fibrillation
 A heart rhythm disorder (arrhythmia). It usually
involves a rapid heart rate, in which the upper heart
chambers (atria) are stimulated to contract in a very
disorganized and abnormal manner.
 A type of supraventricular tachyarrhythmia
 The most common arrhythmia
Aetiology
 Rheumatic heart disease
 Coronary heart disease
(MI)
 Hypertension
 Myopericarditis
 Hypertrophic
cardiomyopathy
 Cardiac surgery




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
Thyrotoxicosis
Infection
Alcohol abuse
Pulmonary embolism
Caffeine
Exercise
 Lone AF
NHS QIS Clinical Standards Audit 2010:
AF PREVALENCE IN SCOTLAND
NHS QIS Clinical Standards April 2010 - Heart Disease
Population with AF
Submitted Practices
Population
Numerator
Denominator
1,512
112,292
1.3%
483
29,581
1.6%
Fife
1,357
96,989
1.4%
Forth Valley
2,064
142,264
1.5%
Greater Glasgow & Clyde
9,625
673,305
1.4%
790
60,598
1.4%
Lanarkshire
1,700
129,339
1.3%
Lothian
1,354
98,918
1.3%
Orkney
69
4,189
1.4%
Shetland
138
9,849
1.6%
Tayside
237
12,617
1.4%
Western Isles
141
6,893
1.9%
19,470
1,376,834
1.4%
NHS Board Residence (HB)
Ayrshire & Arran
Dumfries & Galloway
Highland
SCOTLAND
Percentage (%)
Classification
 New / Recent onset
 < 48 hours
 Paroxysmal
 variable duration
 self terminating
 Persistent
 Non-self terminating
 Cardiovertable
 Permanent
 Non-self terminating
 Non-cardiovertable
Symptoms / Signs
 Breathlessness /
dyspnoea
 Palpitations
 Syncope / dizziness
 Chest discomfort
 Stroke / TIA
 6 x risk of CVA
 2 x risk of death
 18 x risk of CVA if
rheumatic heart disease
 Irregularly irregular pulse
 Atrial rate
 300-600bpm
 Ventricular rate depends
on degree of AV block
 120-160bpm
 Peripheral rate
slower (pulse deficit)
Investigations
 Electrocardiogram (ECG)
 All patients
 May need ambulatory monitoring
 Transthoracic echocardiogram (TTE)
 Establish baseline
 Identify structural heart disease
 Risk stratification for anti-thrombotic therapy
 Transoesophogeal echocardiography (TOE)
 Further valve assessment
 If TTE inconclusive / difficult
Normal Sinus Rhythm
‘Fast’ AF
‘Slow’ AF
Investigations
 Electrocardiogram (ECG)
 All patients
 May need ambulatory monitoring
 Transthoracic echocardiogram (TTE)
 Baseline
 Structural heart disease
 Risk stratification for anti-thrombotic therapy
 Transoesophogeal echocardiography (TOE)
 Further valve assessment
 TTE inconclusive / difficult
Diagnosis
 Based on:
 ECG
 Presentation
 Response to treatment
Treatment objectives
 Rhythm / rate control
 Stroke prevention
Treatment strategies
 New / Recent onset
 Cardioversion
 Rhythm control
 Paroxysmal
 Rate control or
cardioversion during
paroxysm
 Rhythm control if
needed
 Persistent
 Cardioversion
 Rhythm control
 Peri-cardioversion
thromboprophylaxis
 Permanent
 Rate control
 Thromboprophylaxis
Pharmacological Options

Class Ic Anti-arrhythmics
 Flecainide / Propafenone
 Rhythm control
 May also be pro-arrhythmic

Class II Anti-arrhythmics

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Beta-blockers
Mainly rate control
Control rate during exercise and at rest
Generally first choice
Choice depends on co-morbidities

Class III Anti-arryhthmics





Amiodarone / Dronedarone
Mainly rhythm control
May be pro-arrhythmic
Concerns over toxicity
Class IV Anti-arryhthmics
 Calcium channel blockers (verapamil / diltiazem only)
 Rate control only
 Alternative to beta-blockers if no heart failure

Digoxin
 Rate control only
 Does not control rate during exercise
 Third choice unless others contra-indicated
Acute AF
Treatment will depend on:




History of AF
Time to presentation (<> 24 hours)
Co-morbidities (CHD, CHF/LVSD etc)
Likelihood of success (History)
 Rate Vs. Rhythm control
 Rhythm control not feasible or safe
 Beta-blocker
 Verapamil
 Digoxin (CHF)
 Rhythm control if possible and safe
 DC cardioversion (if possible)
 Amiodarone (CHD or CHF/LVSD)
 Flecainide (Paroxysmal AF)
Paroxymal AF
 Rhythm control*
 Antithrombotic therapy as
per risk assessment
 Beta-blocker
 Aspirin 75-300mg
 Class 1c agent or sotalol
 warfarin to INR 2-3
 If CHD - sotalol
 See later
 If LVD: Amiodarone
 Dronedarone?
 Not if heart failure
*May be “Pill in the pocket”
Persistent AF
 Rhythm control
 Beta blocker
 No structural heart
disease: Class 1c* or
sotalol
 Structural heart
disease: amiodarone
 Rate control
 As for permanent AF
* not if CHD present
 Antithrombotic therapy as
per risk assessment
 Pre-cardioversion
thromboprophylaxis of at
least 3 weeks
 If rate control, as for
permanent AF
Permanent AF
 Beta blocker or
 Antithrombotic therapy as per
risk assessment
 Calcium channel blocker
and/or
 Aspirin 75-300mg
 Digoxin
 Warfarin to INR 2-3
 See later
 Amiodarone?
 Option if poor rate
control on above
 Dronedarone?
 Increased mortality
Stroke prevention
(non-rheumatic AF)
Stroke Risk Assessment
(CHADS2)

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C
H
A
D
S
Chronic Heart Failure (1 point)
Hypertension (1 point)
Age > 75 years (1 point)
Diabetes (1 point)
Stroke, TIA or systemic embolisation (2 points)
 Score < 2: low risk, aspirin* or anticoagulant
 Score ≥ 2: high risk, anticoagulant indicated
*Evidence for aspirin is weak
Stroke Risk Assessment
(CHA2DS2VASc)
 Alternative to CHADS2

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C
H
A
D
S
V
A
Sc
Chronic Heart Failure (1 point)
Hypertension (1 point)
Age > 75 years (2 points)
Diabetes (1 point)
Stroke, TIA or systemic embolisation (2 points)
vascular disease (1 point)
Age 65-74 years (1 point)
Sex category (1 point if female)
 Score ≥2 = High risk – anticoagulate unless
contraindicated
Bleeding Risk Assessment
(HAS-BLED)
 1 point each for:



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


Hypertension
Abnormal renal/liver function (1 for each)
Stroke
Bleeding history or predisposition
Labile INR
Elderly (age over 65)
Drugs*/alcohol** concomitantly (1 for each)
*Drugs that increase bleeding, e.g. aspirin
** Alcohol excess
Anticoagulants

Warfarin remains standard anticoagulant at present

3 new oral anticoagulants

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Dabigatran (Direct thrombin inhibitor)
 Licensed by MHRA
 Approved by SMC
Rivaroxiban (Factor Xa inhibitor)
 Licensed by MHRA
Apixaban (Factor Xa inhibitor)
Fixed doses
No monitoring
At least as effective as warfarin
Safer than warfarin?
Dabigatran capsules not stable outside of original blister
Very difficult to reverse effect unlike warfarin
Much more expensive (even allowing for INR costs)
Place in therapy not clear yet
Dabigatran Consensus
NHS in Healthcare Improvement Scotland Working Group:
National consensus on dabigatran
The consensus statement states that:

on balance of risks and benefits, warfarin remains the anticoagulant of
clinical choice for moderate or high risk atrial fibrillation patients (CHA2DS2VASc ≥ 2) with good INR control, and

clinicians should consider prescribing dabigatran in patients with:

poor INR control (less than 60% of time in INR range) despite evidence that
they are complying, or

allergy to or intolerable side effects from coumarin anticoagulants.

http://www.healthcareimprovementscotland.org/default.aspx?page=13900
Conclusions
 AF is a common condition.
 Patients may be unaware of its presence and are
therefore at risk of a stroke
 Effective treatment strategies exist to control
symptoms
 Effective treatment strategies exist to reduce the
risk of stroke
 Patient education and choice are central to
improving the likelihood of treatment success