Atrial Fibrillation Cardioversion

Aka: Atrial Fibrillation Cardioversion, Atrial Fibrillation Rhythm Control

1. See Also
   1. Guidelines 2000 CPR and Emergency Cardiovascular Care
   2. Atrial Fibrillation
   3. Atrial Fibrillation Acute Management
   4. Atrial Fibrillation Anticoagulation
   5. Atrial Fibrillation Rate Control
2. Indications: Acute Atrial Fibrillation
   1. No significant left atrial enlargement
      1. Consider echocardiogram prior to cardioversion
      2. Left atrium >4.5 cm poorly maintains sinus rhythm
   2. Short duration of Atrial Fibrillation (<48 hours)
      1. Chronic Atrial Fibrillation less likely to convert
3. Indications: Chronic Atrial Fibrillation
   1. Symptomatic patients
   2. Younger patients
   3. Poor rate control with recurrent hospitalizations
   4. Lone Atrial Fibrillation with initial presentation
   5. Precipitating factor has been corrected or controlled
4. Contraindications
   1. Atrial Fibrillation >48 hours without Anticoagulation
      1. Delay cardioversion until Anticoagulation has been therapeutic for at least 3-4 weeks
      2. Risk of embolization from atrial thrombi
      3. Early cardioversion ok if cleared with TEE first
         1. See Atrial Fibrillation Anticoagulation
5. Precautions
   1. Atrial Fibrillation Rate Control is preferred for most patients due to adverse events with Antiarrhythmics
      1. Carlsson (2003) J Am Coll Cardiol 41(10): 1690-6
6. Protocol: Admit to hospital to start Antiarrhythmics
   1. Observe for proarrhythmic effect
      1. Antiarrhythmics Class Ia and III
         1. Cause Torsades (with Prolonged QT)
         2. Incidence within first 4 days is common
   2. Admission is standard of care in U.S.
      1. Not admitted in Europe and Canada
   3. Admit especially for
      1. Antiarrhythmics Class Ia and Ic drugs
      2. Poor left ventricular function
      3. Coronary Artery Disease
      4. History proarrhythmia
   4. Admission not necessary
      1. Implanted Defibrillator in place
7. Protocol: Electrical Synchronized Cardioversion
   1. Dose: 100-360 joules (Synchronized)
   2. Conversion Rate: 67-94%
8. Protocol: Preferred agent summary
   1. No organic heart disease
      1. First choice: Flecainide or Propafenone
      2. Second choice: Sotalol
      3. Other: Amiodarone, Dofetilide
   2. Coronary Artery Disease
      1. First choice: Sotalol
      2. Second choice: Amiodarone, Dofetilide
   3. Congestive Heart Failure
      1. Amiodarone
      2. Dofetilide
   4. Left Ventricular Hypertrophy (>1.4 cm thick wall)
      1. Amiodarone
9. Protocol: Pharmacologic Cardioversion if WPW Syndrome
   1. General
      1. Consider for Atrial Fibrillation <48 hours
      2. See Atrial Fibrillation Anticoagulation for >48 hours
   2. Avoid Harmful agents
      1. Adenosine
      2. Beta Blocker
      3. Calcium Channel Blocker
      4. Digoxin
   3. Recommended agents (Use only 1 agent)
      1. Electrical Synchronized Cardioversion (See above)
      2. Class IA Agents
         1. Procainamide
      3. Class IC Agents
         1. Propafenone (Rythmol)
         2. Flecainide (Tambocor)
      4. Class III Agents
         1. Amiodarone (Cordarone)
         2. Sotalol (Betapace)
10. Protocol: Pharmacologic Cardioversion if Normal cardiac function
    1. General
       1. Consider for Atrial Fibrillation <48 hours
       2. See Atrial Fibrillation Anticoagulation for >48 hours
    2. Recommended agents (Use only 1 agent)
       1. Electrical Synchronized Cardioversion (See above)
       2. Class IA Agents
          1. Procainamide
       3. Class IC Agents
          1. Propafenone (Rythmol)
          2. Flecainide (Tambocor)
       4. Class III Agents
          1. Amiodarone (Cordarone)
          2. Ibutilide (Corvert)
11. Protocol: Pharmacologic Cardioversion if Ejection Fraction <40%
    1. General
       1. Consider for Atrial Fibrillation <48 hours
       2. See Atrial Fibrillation Anticoagulation for >48 hours
    2. Recommended agents
       1. Electrical Synchronized Cardioversion (See above)
       2. Amiodarone (Cordarone)
12. Protocol: Intermittent Atrial Fibrillation (prn use)
    1. Indications: Episodic Atrial Fibrillation
       1. Fewer than 12 Atrial Fibrillation episodes yearly
    2. Contraindications
       1. Congestive Heart Failure or other structural heart disease
       2. Coronary Artery Disease
    3. Protocol (Initiated by Cardiology)
       1. Cardiologists prescribe agent
          1. Flecainide (Tambicor) 200-300 mg
          2. Propafenone (Rhythmol) 600 mg
       2. Patient takes agent as needed at a. fib symptom onset
          1. Expect improvement within 2 hours of pill
          2. High rate of cardioversion within 8 hours
       3. ER indications
          1. No improvement in 2 hours
          2. Pulse increases after dose (Atrial Flutter)
       4. Safety
          1. Low Incidence of proarrhythmia
    4. References
       1. (January 2005) Prescriber's Letter, p. 6
13. References
    1. (2000) Circulation, 102(Suppl I):86-9
       1. http://www.circulationaha.org
    2. Chevalier (2003) J Am Coll Cardiol 41:255-62
    3. King (2002) Am Fam Physician 66:249-56