Atrial Fibrillation

An overview of the basic principles of AF management and diagnosis.

 

Lecture by

Video Duration: 11 minutes

  • Atrial Fibrillation
    Created by Sophie Banks
    General
    Epidemiology

    Chaotic, irregular atrial rhythm at 300-600bpm

    Common in the elderly (<9%)

    Pathology

    AV node responds intermittently = irregular ventricular rate

    Cardiac output drops by 10-20% as ventricles not primed reliably by atria

    Top three causes

    Ischaemic heart disease

    Rheumatic heart disease

    Thyrotoxicosis

    Clinical Features
    Symptoms

    May be asymptomatic

    Chest pain, palpitations, dyspnoea or faintness

    Signs

    Irregular irregular pulse

    1st heart sound of variable intensity

    Signs of LVF (pulmonary oedema - tachypnoea, orthopnoea, PND, frothy sputum etc)

    Investigations
    Cultures

    Urine dip/ culture - if suspect infection (as can trigger AF)



    Bloods

    Bloods - U&Es, cardiac enzymes, TFTs

    Imaging

    ?Echo - left atrial enlargement, valve disease, poor LV function

    Scopic/Biopsy

    None

    Functional

    ECG - absent p waves, irregularly irregular QRS complexes

    Treatment
    Conservative

    If asymptomatic, address any other medical problems - control HTN, DM, cholesterol, diet, exercise etc to prevent future cardiovascular events.

    Medical

    1. Rate control

    Step 1: Beta blocker OR Rate-limiting CCB

    Step 2: Digoxin OR amiodarone

    2. Rhythm control

    Electrical: DC cardioversion

    Pharmacological: Flecanide


    3. Anticoagulation (based on CHA2DS2-VaSc vs HAS-BLED scores) - use warfarin (aim INR 2-3) or NOACs

    Surgical

    AV node ablation/ pulmomary vein ablation