Atrial fibrillation (main): Difference between revisions
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*'''ACCP Recommendations'''
*'''ACCP Recommendations'''
**In patients with AF, including those with paroxysmal AF, with only one of the risk factors listed immediately above, we recommend long-term antithrombotic therapy ([[EBQ:Evidence_Levels|Grade 1A]]), either as anticoagulation with an oral VKA, such as warfarin [[EBQ:Evidence_Levels|(Grade 1A)]], or as aspirin, at a dose of 75-325 mg/d ([[EBQ:Evidence_Levels|Grade 1B]])<ref name="ACCP">Singer DE et al. Antithrombotic therapy in atrial fibrillation: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition).Chest. 2008 Jun;133(6 Suppl):546S-592S</ref>
**In patients with AF, including those with paroxysmal AF, with only one of the risk factors listed immediately above, we recommend long-term antithrombotic therapy ([[EBQ:Evidence_Levels|Grade 1A]]), either as anticoagulation with an oral VKA, such as warfarin [[EBQ:Evidence_Levels|(Grade 1A)]], or as aspirin, at a dose of 75-325 mg/d ([[EBQ:Evidence_Levels|Grade 1B]])<ref name="ACCP">Singer DE et al. Antithrombotic therapy in atrial fibrillation: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition).Chest. 2008 Jun;133(6 Suppl):546S-592S</ref>
**In patients with AF, including those with paroxysmal AF, who have two or more of the risk factors for future ischemic stroke listed immediately below, we recommend long-term anticoagulation with an oral VKA ([[[[EBQ:Evidence_Levels|Grade 1A]]).<ref name="ACCP"></ref>
**In patients with AF, including those with paroxysmal AF, who have two or more of the risk factors we recommend long-term anticoagulation with an oral VKA ([[[[EBQ:Evidence_Levels|Grade 1A]]).<ref name="ACCP"></ref>


==Disposition==
==Disposition==

Revision as of 15:24, 26 January 2015

Background

Atrial fibrillation (AF) categories:

  • First detected episode
  • Recurrent (after 2 or more episodes)
  • Paroxysmal (if recurrent AF terminates spontaneously)
  • Persistent (if sustained beyond 7 days)

Causes:

  • Cardiac (atrial enlargement)
    • Hypertension
    • Ischemic heart disease
    • Rheumatic heart disease
      • Valvular heart disease (any lesion that leads to significant stenosis or regurgitation)
  • Noncardiac (increased automaticity)
    • Thyrotoxicosis
    • Chronic lung disease
    • Pericarditis
    • Ethanol ("holiday heart")
    • PE
    • Drugs (cocaine, TCA)

Clinical Features

  1. Asymptomatic - 44%
  2. Palpitations - 32%
  3. Dyspnea - 10%
  4. Stroke - 2%
  5. Also can present with decompensated heart failure, acute pulmonary edema

Diagnosis

  • 3 patterns on ECG:
  1. Typical
    1. Irregularly, irregular R waves
    2. QRS rate 140-160/min
  2. Large fibrillatory waves
    1. May look like flutter waves
      1. Unlike a-flutter, the fibrillatory waves are irregular
  3. Slow, regular A-fib
    1. Due to complete AV block with escape rhythm
  • Ischemic changes?
  • Rate > 250? (think preexcitation)

Work-Up

  1. ECG
  2. Digoxin level (if appropriate)
  3. Chem-10
  4. TSH & free T4 (AF increased in subclinical hyperthyrodism)
  5. Eval for ACS only in:
    1. Pt with ECG changes suggestive of ischemia, hypotension, angina
    2. AF is rarely only manifestation of ACS, although RVR and hypotension can provoke demand ischemia

Treatment

  • Rate control
  • Anti-thrombotic therapy
    • Chronic and paroxysmal a fib are associated with thrombus formation

CHADS2 Score

  1. CHF (1pt)
  2. HTN (1pt)
  3. Age>75 (1pt)
  4. DM (1pt)
  5. Stroke/TIA (2pts)
  • Score 0: consider no treatment or ASA
  • Score 1: consider warfarin or ASA
  • Score 2-6: consider warfarin (INR goal = 2-3)
  • All patients with valvular disease should be on anticoagulation

Anticoagulation in Atrial Fibrilation/Flutter

  • ACCP Recommendations
    • In patients with AF, including those with paroxysmal AF, with only one of the risk factors listed immediately above, we recommend long-term antithrombotic therapy (Grade 1A), either as anticoagulation with an oral VKA, such as warfarin (Grade 1A), or as aspirin, at a dose of 75-325 mg/d (Grade 1B)[1]
    • In patients with AF, including those with paroxysmal AF, who have two or more of the risk factors we recommend long-term anticoagulation with an oral VKA ([[Grade 1A).[1]

Disposition

  • Similar outcomes for Canadian vs. American strategies, despite lower admission rates in Canada[2]

Canadian

  • "Limit hospital admission to highly symptomatic patients in whom adequate rate control cannot be achived"[3]

American

Indications for hospitalization:

  • Pt with acute heart failure or hypotension after rhythm or rate control
  • AF 2/2 HTN, infection, COPD exacerbation, PE, ACS/MI
  • Age > 60 (high risk of thromboembolism, more likely to have comorbidities)
  • Initiation of heparin or other anticoagulant
  • If considering ablation of accessory pathway in pt with AF
  • Symptomatic recurrence in the ED
  • Hemodynamic instability

Indications for discharge (low-risk pts): Discharge with urgent cardiology f/u

  • <60 years old
  • No significant comorbid disease
  • No clinical suspicion for PE or MI
  • Conversion in ED or rate control

Complications

  1. Hemodynamic compromise
    1. A-fib lowers CO by 20-30%
    2. Impaired coronary blood flow
  2. Arrhythmogenesis
  3. Arterial thromboembolism

See Also

Source

  • UpToDate
  • Annals of EM; Jan 2011. 57(1)
  • EBmedicine.net
  1. ↑ 1.0 1.1 Singer DE et al. Antithrombotic therapy in atrial fibrillation: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition).Chest. 2008 Jun;133(6 Suppl):546S-592S
  2. ↑ Rising KL. Home is Where the Heart Is. Annals of Emergency Medicine. 2013;62(6):578-579
  3. ↑ Stiell, et al. Atrial Fibrilation Guidelines. Canadian Cardiovascular Society Atrial Fibrillation Guidelines 2010: management of recent-onset atrial fibrilation and flutter in the emergency department. Can J Cardiolol. 2011;27:38-46
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