Transcript Atrial Fibrillation - NHS Education for Scotland

Atrial Fibrillation
Steve McGlynn
Specialist Principal Pharmacist (Cardiology),
Greater Glasgow and Clyde
Honorary Clinical Lecture,
University of Strathclyde
Some types of arrhythmia
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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
Incidence / Prevalence
 1.7 / 1000 patients / year
 3 / 1000 patients / year
(>60 years)
 0.4 - 1% (overall)
 2 – 4% (>60 years)
 >8% (>80 years)
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
Atrial Flutter
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
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Class Ic Anti-arrhythmics
 Flecainide / Propafenone
 Rhythm control
 May also be pro-arrhythmic
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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
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Class III Anti-arryhthmics
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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
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Digoxin
 Rate control only
 Does not control rate during exercise
 Third choice unless others contra-indicated
Acute AF
Treatment will depend on:
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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?
*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?
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
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)
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 (unlicensed for AF as of June 2011)
 Dabigatran (Direct thrombin inhibitor)
 Rivaroxiban (Factor Xa inhibitor)
 Apixaban (Factor Xa inhibitor)
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Fixed doses
No monitoring
At least as effective as warfarin
Safer than warfarin?
Much more expensive (even allowing for INR costs)
Place in therapy not clear yet
Conclusions
 AF is a common condition.
 Patients may be unaware of its presence and are
therefore at risk of a stroke
 Alternative treatment strategies exist to control
symptoms
 Alternative treatment strategies exist to reduce the
risk of stroke
 Patient education and choice are central to
improving the likelihood of treatment success