Atrial Fibrillation

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Atrial Fibrillation

• Maggie Kelly

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Atrial FibrillationWhat will be covering today

• Prevalence
• Signs Symptoms
• Diagnosis
• Possible causes
• Anti-coagulation
• Treatments
• Management

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Introduction

• Atrial Fibrillation is the commonest arrhythmia
• Many patients have few symptoms and it is
  sometimes regarded as a fairly trivial
  unimportant disorder
• A/F affects 1 of the total population
• Rising to 4 in over 65 years old and increasing
  to aprox 10 of people over 75 years old
• Locally 5000 patients gt 55 with AF
• Each GP 40 pts with AF

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Effects of A/F

• It accounts for 1/3 of all admissions for
  arrhythmias
• There is a loss of atrial systolic function
• Congestive Cardiac Failure can be precipitated by
  A/F
• All cardiovascular death risk is in increased for
  patients with A/F
• 2.0 x higher for men with A/F
• 2.7 x higher for women with A/F
• It absorbs 1 of the NHS budget

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Stroke and A/F

• Untreated A/F increases the risk of stroke by a
  factor of 5.
• The incidence of stroke with patients with A/F is
  5 per year
• Stroke risk is increased by-
• x 16 patients have A/F mitral stenosis
• x 3.5 if previous thrombolic event
• x 1.7 for those with diabetes
• x 2.5 for patients with LVSD

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What is Atrial Fibrillation

• Atrial Fibrillation (AF) is a supraventricular
  tachyarrhythmia (an abnormal rapid, chaotic heart
  beat arising in the atria) characterized by
  uncoordinated atrial activation with consequent
  deterioration of atrial mechanical function.
• In effect, the atria quiver and fail to perform
  their pumping function of filling the ventricles.
  The lack of atrial pumping action and the
  resultant pooling of blood presents opportunities
  for the formation of thrombi leading to embolic
  stroke.
• AF also affects the pumping rhythm of the
  ventricles by increasing heartbeat and thus
  lowering pumping efficiency.

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ATRIAL FIBRILLATIONpathophysiology

• Defined by the absence of coordinated atrial
  systole
• Results from multiple re-entry electrical waves
  that move randomly about the atria
• Enhanced automaticity in left atria -gt electrical
  remodeling with shortening of the atrial
  refractory period -gt atrial fibrillation

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Normal ECG Sinus Rhythm
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Atrial fibrillation

• This ECG shows a heart in atrial fibrillation The
  most obvious difference is the absence of the P
  wave. Leads I, II, and III show the classical
  appearance of AF, the "undulating baseline". The
  tracing never really "sits still". The distance
  between each QRS complex in the rhythm strip
  illustrates that the heart rhythm is irregular.
  There is no pattern to the irregularity, so the
  rhythm of AF is called "irregularly irregular".

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Atrial Flutter

• This ECG illustrated a heart in atrial flutter.
  This has very distinct appearance. The "flutter
  waves" that we expect to see in atrial flutter
  are noticeable throughout the ECG, but are very
  easy to see in the rhythm strip. The rhythm is
  still regular, although this is not always the
  case.

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Classification of Atrial Fibrillation

• Treatments management differ according to type
  symptoms.
• Paroxysmal.
• Intermittent episodes of A/F /or Atrial Flutter.
• Chronic
• Persistent. Sustained A/F indicates the
  potential for restoration of Sinus Rhythm.
• Permanent. Return to S/R is not possible.

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Three Phases of Management

• Search for the underlying cause
• Control arrhythmia and reduce thromboembolic risk
  
• Rate or Rhythm control. Consider cardioversion
  to sinus rhythm if appropriate. Chemically or
  electrically.

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Common Causes

• Ischaemic heart disease
• Hypertension
• Rheumatic non rheumatic valve disease. Mitral
  valve disease especially stenosis.
• Myocardial Infarction
• Thyrotoxicosis
• Excess Alcohol

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Signs Symptoms

• Shortness of breath on exercise or at rest
• Dizziness
• Tiredness
• Palpitations
• Can be very frightening for the patient
• Embolic episode
• Chest pain
• Falls
• Or no symptoms at all

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Importance of Treatment

• To relieve symptoms of
• Heart failure
• Hypotension
• Chest Pain
• Relieve of anxiety

• Medically
• To improve overall cardiac function
• To improve exercise tolerance
• To reduce the risk of thromboembolism and stroke

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Investigations

• 12 Lead ECG
• Is it A/F?
• Patient History
• Is it Paroxysmal?
• 24 Hour Tape
• Echocardiograph
• Exercise Test
• Bloods

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ATRIAL FIBRILLATIONTherapeutic Approaches

• Anticoagulation
• Antiarrhythmic suppression
• Control of ventricular response
• Pharmacotherapy
• Catheter modification/ablation of AV node
• Curative procedures
• Surgery (maze)
• Catheter ablation

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Persistent ATRIAL FIBRILLATIONtreatment options

• Rate or Rhythm Control
• The management for A/F is either to attempt to
  control ventricular rate.
• Or
• To restore and maintain Sinus Rhythm

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Rhythm Control

• For patients with recent onset.
• Options are
• Ablation implantation of a pacemaker
• Surgery
• Cardioversion
• Elective DC cardioversion or Drug therapy
  (pharmalogical)

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Monitoring

• Will require regular INRs
• INR should be between 2 to 4
• Potassium levels 4 mmol ( hypo hyperkloemia
  precipitate heart rhythms)
• Signs of LVF
• Will require monitoring/treatment of underlying
  cause
• If patients are to undergo elective DC
  cardioversion they will require INRs and K done
  every 7 to 10 days for six weeks prior to
  procedure

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AFTER SUCCESSFUL CARDIOVERSION

• MUST CONTINUE
• ANTICOAGULATION FOR AT LEAST 12 WEEKS

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Permanent ATRIAL FIBRILLATIONMedical Rate
Control treatment options

• In patients with permanent AF, who need treatment
  for ventricular rate control
• Beta blockers or rate limiting calcium
  antagonists should be the preferred initial
  mono-therapy in all patients
• Digoxin should only be considered as mono-therapy
  in predominately sedentary patients
• Aim of heart rate control is
• Minimise symptoms associated with fast HR
• Prevent tachycardia associated cardiomyopathy

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RATE CONTROL

• Pharmacological
• DIGOXIN
• SOTOLOL
• VERAPAMIL OR DILTIAZEM
• AMIODARONE
• Continue adequate anti-coagulation

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Rate Control

• Rate control strategies with traditional drugs
  such as Digoxin, calcium channel blockers beta
  blockers are as good as, or even better, than
  rhythm control by pharmacological or electrical
  methods

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Monitoring

• Will require regular INRs
• between 2 to 4
• Potassium levels 4 mmol ( hypo hyperkloemia
  precipitate heart rhythms)
• Signs of LVF
• Will require monitoring/treatment of underlying
  cause
• Digoxin levels

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Paroxysmal ATRIAL FIBRILLATIONtreatment options

• Patients with paroxysmal AF can be highly
  symptomatic
• Three main aims of treatment for paroxysmal AF
  are to
• suppress paroxysms of AF and maintain sinus
  rhythm
• control heart rate during paroxysms of AF
• prevent complications
• In patients experiencing infrequent, or mild
  symptoms may not require any drug treatment but
  consider daily 75 mg aspirin

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Paroxysmal ATRIAL FIBRILLATIONtreatment options

• Beta blockers should be initial therapy in
  patients experiencing symptomatic paroxysms
• Patients with PAF no structural heart disease
  may be considered for treatment with either
  Flecainide, Propafenone or Sotalol
• Patients with PAF CVD may be considered for
  Sotalol if symptoms persist on beta blockers,
  Amiodarone or referral for non-pharmacological
  intervention
• All patients should be stratified in respect of
  their thromboembolic risk and treated accordingly

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Paroxysmal ATRIAL FIBRILLATIONnon-pharmacological
treatment

• All patients should be considered for referral
  if
• anti-arrhythmic therapy is ineffective
• therapy side-effects intolerable
• ablation preferred treatment (WPW)
• Pulmonary vein isolation (PVI) for, usually
  younger, patients, resistant to pharmacotherapy
• AVN ablation pacing improves symptom burden and
  exercise tolerance, although require long term
  pacing and thromboprophylaxis
• Surgery (MAZE procedure) may still be performed
  in patients with PAF undergoing concomitant (e.g.
  MV) surgery

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ATRIAL FIBRILLATIONStroke and thromboembolic
riskstratification

• AF is an independent risk factor for stroke
  thromboembolic events
• Risk increases with age, HTN, vascular disease
  (especially occlusive CVA/TIA), DM, valvular
  heart disease LVSD
• This allows for relatively easy risk
  stratification based on clinical criteria alone
• Benefits of thromboprophylaxis in AF are well
  established, especially Warfarin in high or
  moderate risk patients

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Future

• A/F is likely to become more of a challenge for
  primary secondary care clinicians
• Rate Control is likely to become the main
  therapeutic goal in older patients
• Therapeutic advances with oral anti-coagulation
  will facilitate community based management of
  patients with A/F

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Heart Improvement Atrial Fibrillation in Primary
Care National Priority Project NICE
Implementation Guidelines June 2006
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Any Questions

• Thank you