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Showing posts with label management of AF. Show all posts

Management of Atrial Fibrillation

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Atrial Fibrillation is the commonest sustained cardiac arrhythmia, occurring in 1-2% of the population.  Its incidence increases with age: <0.5% of the population are affected aged 40-50 but up to 15% are affected by the age of 80.

This article focuses on the management of AF, looking at:
    A) Management of permanent/persistent AF
    B) Management of paroxysmal AF 


A) Management of permanent/persistent atrial fibrillation

This requires consideration of 2 questions:
       1) rhythm control or rate control?
       2) to anticoagulate or not?

So to consider question 1:
  • Rhythm control?
    • NICE suggests rhythm-control first in:
      • younger patients
      • those with symptoms
      • presenting for the first time with lone AF
      • those with AF secondary to a treated or correct precipitant
      • with congestive heart failure
    • Treatment options are:
      • DC cardioversion
      • Chemical cardioversion 
        • amiodarone, sotalol or flecanide (the latter only in a structurally normal heart)
  • Rate control?
    • NICE recommends trying rate-control first in:
      • over 65s
      • patients with coronary artery disease
      • in those with contraindications to antiarrhythmic drugs
      • in patients who are unsuitable for cardioversion
        • left atrium >5.5cm
        • mitral stenosis
        • contraindications to anticoagulation
        • longstanding AF (>12 months)
        • multiple failed attempts at cardioversion 
    • Treatment options are:
      • beta blocker
      • rate-limiting calcium antagonist
      • digoxin

And then there is question 2: to anticoagulate or not:
  • You can stratify risk using either the NICE stroke risk stratification (2006) or the CHA2DS2-VASc score (2010):
    • Using the Nice Stroke Risk stratification:
      • Define the 'risk' in the patient:
        • High Risk
          • Previous ischaemic stroke/TIA/thromboembolic event
          • age >/= 75 with hypertension, diabetes or vascular disease
          • clinical evidence of valve disease, heart failure or LV dysfunction
        • Medium Risk
          •  age >/=65 with no high risk factors or age <75 with hypertension, diabetes or vascular disease
        • Low Risk
          • age <65 with no high or moderate risk factors
      • Unless contraindications, anticoagulate all high risk patients with warfarin (target INR 2.5) and all low risk patients with aspirin.
      • Consider whether to use warfarin or aspirin in moderate risk patients on an individual basis
      • NB: 2012 European Society of Cardiology guidelines suggest that use of aspirin monotherapy should be avoided now there are 'novel oral anticoagulants'
    • Using the CHA2DS2-VASc score
      • Depends on points
        • Congestive heart failure/LV dysfunction: 1 point
        • Hypertension: 1 point
        • Age >/= 75: 2 points
        • Diabetes: 1 point
        • Stroke/TIA/thromboembolism: 2 points
        • Vascular disease (= MI, PVD, aortic plaque): 1 point
        • Age 65-74: 1 point
        • Sex catagory: if female, 1 point
      • Any score of 1 or more warrants anticoagulation
  • The world of AF anticoagulation has recently got far more complex, as in addition to warfarin and aspirin you must now consider dabigatran and rivaroxaban:
    • Dabigatran (= oral direct thrombin inhibitor)
      • can be considered instead of warfarin in patients with nonvalvular AF who have one or more of the following risk factors:
        • previous stroke/TIA/systemic embolism
        • LVEF <40%
        • HF NYHA class 2 or above
        • age 75 or older
        • age 65 or older with diabetes, hypertension or coronary artery disease
      • The trial that proved non-inferiority compared to warfarin was the RE-LY trial
    • Rivaroxaban (mechanism of action: directly inhibits factor Xa) 
      • can be considered instead of warfarin in patients with nonvalvular AF who have one or more of the following risk factors:
        • previous stroke/TIA
        • hypertension
        • congestive cardiac failure
        • age 75 or older
        • diabetes mellitus 
      • The trial that proved non-inferiority compared to warfarin was the ROCKET-AF trial

DC Cardioversion
  • Anticoagulation:
    • Before cardioversion, patients should be on warfarin with an INR of 2-3 for at least 3 weeks.
    • After successful cardioversion, they should remain on warfarin with an INR of 2-3 for at least 4 weeks.
    • If cardioversion cannot be postponed for 3 weeks, give heparin beforehand and warfarin for at least 4 weeks afterwards
    • If the duration of AF is confirmed as less than 48 hrs no anticoagulation pre-cardioversion is needed.
  • If previous DCCV was unsuccesful, give amiodarone or sotalol for at least 4 weeks prior to subsquent cardioversion attempt
  • If no cause for the AF identified, consider medications post cardioversion to help maintain sinus rhythm:
    • beta blocker first line
    • if beta blocker fails:
      • sotalol or flecainide if heart structurally normal
      • amiodarone if not structurally normal

 B)  Management of paroxysmal AF

Again, this requires consideration of 2 questions:

1) Pill in pocket therapy or 'normal' ongoing treatment?
2) To anticoagulate or not?

To answer question 1:
  • 'Pill in pocket' therapy is used if:
    • Patient has no LV dysfunction, valvular heart disease or IHD
    • Patient have infrequent symptomatic episodes
    • Patient has a SBP >100 and resting HR >70
    • Patient is able to understand how to use this approach
  • If all of the above criteria are not fullfilled:
    • give standard beta blocker
    • if this fails
      • try sotalol in CAD
      • amiodarone in LV dysfunction
      • flecanide in a structurally normal heart
    • If sotalol/flecanide fails, amiodarone can be trialled

The method of determining whether to anticoagulate or not is exactly the same as in permanent AF.


 Other points
  • Post-TIA, give warfarin as soon as possible once bleed/infarct has been excluded
  • Post stroke, start warfarin 2 weeks afterwards as long as no bleed/large infarct on CT



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Secret collector of interesting anonymised ECGs. Fan of the Bath Photomarathon. Lover of cream teas. [Sarah Hudson] (Your Picture)