6.06 Atrial Fibrillation

October 16, 2018

In this episode we look at the common problem of Atrial Fibrillation (the irregularly irregular heart arrhythmia).

 

Presented by: Dr Jo Preston,  Dr Iain Wilkinson

Faculty: Dr Dan Thomas, Pam Trangmar

Broadcast Date:  16th October 2018

pdf of Sip of MDTea here

Click here for a link to the CPD log for series 6 and we’ll automatically email you a copy for your records.

 

 

 

 


 

Social Media

Iain:

Jo:

Top 10 books about growing old – The Guardian

 


Learning Objectives

Knowledge:

To understand what AF is and be able to explain this to a patient

To know why AF is a risk factor for strokes and how to reduce this risk

 

Skills:

To be able to detect AF by taking the pulse of a patient

To know when to refer a patient for further investigation

 

Attitudes:

To understand that anyone who has contact with a patient might detect AF


Show Notes 

pdf here

Definitions:

 

Atrial fibrillation is a heart condition that causes an irregular and often abnormally fast heart rate.

NHS.uk

 

Practical Definition:

 

Its disordered electrical activity in the atrium which leads to too many electrical impulses trying to get through the AV node. The AV node cuts many out but the result is an irregular ventricular heart beat.

Leads to an irregularly irregular pulse.

Key Points from Discussion

1.     Introduction

This is the most common tachyarrhythmia in older people

  • 0.5% age 50-59
  • 9% age 80-89
  • Risk of AF doubles with each decade of life
    • in 2010 – this was 20 million men and 12 million women.
    • 1 in 4 middle aged adults will develop AF
  • Increases Heart failure 5x
  • Cardiovascular events and all cause mortality 2x
  • CKD 1.6%
  • ⅓ patients who have a stroke have a diagnosis of AF made before, during or immediately after the stroke

Despite good progress in the management of patients with atrial fibrillation (AF), this arrhythmia remains one of the major causes of stroke, heart failure, sudden death, and cardiovascular morbidity in the world. Furthermore, the number of patients with AF is predicted to rise steeply in the coming years.

Increases risk of ischaemic stroke by 5-6x (but can use scoring systems to try and work out a person’s individual stroke risk) – in RCTs the stroke risk is about 1.5%.

ESC AF guideline

Not only is AF a major risk factor for stroke, but when strokes occur in association with AF, patients suffer increased levels of mortality, morbidity and disability with longer hospital stays compared with stroke patients without AF  .

  • This is because then tend to have a large clot that will break off and block the artery (aften the middle cerebral artery) (NICE Guidance AF)

Can be

  • Paroxysmal – terminates spontaneously or with intervention within 7 days
  • Persistent – fails to self terminate within 7 days. often require cardioversion (can be chemical)
  • Permanent – lasted more than 12 months

This flow chart is a good way of thinking about AF management

Taken from ESC 2016

How to make the diagnosis?

    • Manual pulse check – we can all do this! – looking for an irregularly irregular pulse

 

  • The first person that does this when they would not normally do it and lets us know (even if its normal)  will win an MDTea mug!

 

  • We don’t this enough!!

 

 

 

  • ECG – whenever you suspect AF

Ten Commandments’ of 2016 ESC Guidelines for the management of atrial fibrillation.Eur Heart J. 2016 Oct 7;37(38):2853..

  • Suspected PAF – 24 hr ECG or event recorder if symptomatic episodes are >24 hours apart
  • Echocardiogram –
    • for whom a baseline echocardiogram is important for long‑term management
    • for whom a rhythm‑control strategy that includes cardioversion (electrical or pharmacological) is being considered
    • in whom there is a high risk or a suspicion of underlying structural/functional heart disease (such as heart failure or heart murmur) that influences their subsequent management (for example, choice of antiarrhythmic drug)

NICE CG 180

Common causes

There are many of these (it’s a classic question you used to get asked at medical school)

“Give me X number of causes of AF”.

Essentially it’s anything that either leads to an unstable electrical system or a structural change to the atria – and henceforth a change to the electrical system.

 

  • External stressors such as structural heart disease, hypertension, possibly diabetes, but also AF itself induce a slow but progressive process of structural remodelling in the atria.
  • Activation of fibroblasts, enhanced connective tissue deposition, and fibrosis are the hallmarks of this process.
    • In addition, atrial fatty infiltration, inflammatory infiltrates, myocyte hypertrophy, necrosis, and amyloidosis may also be found in AF patients (with their concomitant pre-disposing conditions)
  • Structural remodelling results in electrical dissociation between muscle bundles and local conduction heterogeneities, favouring re-entry and perpetuation of the arrhythmia.
  • In many patients, the structural remodelling process occurs before the onset of AF itself
  • As some of the structural remodelling will be irreversible, early initiation of treatment seems desirable.
  • The functional and structural changes in atrial myocardium and stasis of blood, especially in the left atrial appendage (LAA), generate a prothrombotic milieu
  • The seminal observation by Haissaguerre et al. was that a focal source in the pulmonary veins can trigger AF, and ablation of this source can suppress recurrent AF.

ESC AF Guidelines

Practically:

  • Hypertension
  • Ischaemic heart disease
  • Thyrotoxicosis
  • Infections
  • Electrolyte abnormalities
  • Alcohol
  • Caffeine
  • Anaemia

Symptoms – may be many, may be none!

  • Palpitations
  • Shortness of breath
  • Light headed
  • Fatigue and lethargy also common – about 15% to 20% report a decreased exercise tolerance

May need to go to hospital if

  • Need urgent rate control
  • Hypotension
  • Heart failure

Management

  1. Rate + rhythm control
  2. Stroke prevention

Rate control – may be all you need to do to remove the symptoms – but as compared to stroke prevention and rhythm control there is relatively little evidence here.

May need emergency admission to hospital for

Management of heart failure, hypotension or difficulty controlling rate

If need initiation of antiarrhythmic drug

Treatment of associated medical problem triggering the AF e.g. pnuemonia

Can control rhythm with certain drugs, electrical cardioversion or ablation therapy

When to offer rate or rhythm control (From NICE AF 2014)

NICE guidelines say:

1.6.1 Offer rate control as the first‑line strategy to people with atrial fibrillation, except in people:

  • whose atrial fibrillation has a reversible cause
  • who have heart failure thought to be primarily caused by atrial fibrillation
  • with new‑onset atrial fibrillation
  • with atrial flutter whose condition is considered suitable for an ablation strategy to restore sinus rhythm
  • for whom a rhythm control strategy would be more suitable based on clinical judgement.

 

  • Some of the commonest drugs
    • Beta blockers
    • Calcium channel blockers
    • Digoxin – bgs article

Anticoagulation

  • There is a stroke risk with AF (can be calculated but is in the order of 4-12% per year)
  • But still need to individualise risk
  • To calculate stroke risk use:
    • CHADS2VASC
      • Heart failure
      • Hypertension
      • Age
      • Diabetes
      • Stroke
      • Valvular heart disease
      • Female

To calculate bleeding risk – HASBLED

both are here: https://www.chadsvasc.org/

Important to note that scores aren’t directly comparable i.e score of 2 on HASBLED isn’t same as score of 2 on CHADS2VASC

Also HASBLED can identify risk factors that you can modify so you could stop NSAIDS or Aspirin, control hypertension and reduce alcohol intake to lower the bleeding risk

Can use SPARCTOOL.com (can download to phone) will compare the HASBLED and CHADS2VASC and give a Number needed to treat and Number needed to harm of Warfarin, Apixaban, Rivaroxiban, Edoxaban, Dabigatran

Novel anti-platelet agents and anticoagulants anaesthesia tutorial of the week 30  22nd september 2014. AAGBI

  • Commonly see falls as a reason why people in AF aren’t anticoagulated
  • ‘Choosing antithrombotic therapy for elderly patients with AF at risk of falls’
    • 295 falls in one year before risk of bleeding outweighs stroke risk if in AF on Warfarin and over age 75 (according to one study)

Choosing antithrombotic therapy for elderly patients with atrial fibrillation who are at risk for falls. Arch Intern Med. 1999 Apr 12;159(7):677-85

Commentary in Journal Watch October 2012 here

  • Still see people on Aspirin or Clopidogrel for AF (No longer recommended as per most recent NICE guidance as did not prevent strokes cause by AF but did carry risk of bleeding)
  • Why not Aspirin?
    • No benefit in all cause mortality, ischaemic stroke, systemic emboli or reducing major bleed

What if Warfarin control of poor? (consider DOAC)  if:

  • TTR of 65% or less
  • 1 INR above 8
  • 2 INR above 5
  • 2 INR less than 1.5
  • But can be useful if people don’t want frequent blood tests, have difficulty getting to GP surgery or anticoagulation clinic

Advantages and Disadvantages to various DOACS each is really an individual decision to be taken with the patient.


Curriculum Mapping

Curriculum Area
NHS Knowledge Skills Framework Suitable to support staff at the following levels:

  • Personal and People Development: Levels 1-3
  • Service Improvement: Level 1 – 2
Foundation curriculum 2. Delivers patient centred care and maintains trust

9. Recognises, assesses and initiates management of the acutely ill patient

10. Recognises, assesses and manages patients with long term

conditions

12. Requests relevant investigations and acts upon results

Physician Associate Matrix of Conditions Atrial Fibrillation

Stroke

Core Medical Training The patient as central focus of care

Palpitations

Therapeutics and safe prescribing

Decision making and clinical reasoning

Managing long term conditions and promoting patient self-care

Evidence and guidelines

GPVTS program 3.12 – Cardiovascular health, AF

3.05 – Care of Older Adults – stroke

ANP (Draws from KSF) 7.5 Stroke and cerebrovascular disease

7.7 Atrial fibrillation

Geriatric Medicine – Higher Specialist Training 3.2.3 Presentations of Other Illnesses in Older Persons

3.2.9 Health Promotion – Risk reduction for stroke

28. Diagnosis and Management of Acute Illness

29. Diagnosis and Management of Chronic Disease and Disability

Leave a Reply

The Hearing Aid Podcasts © 2015