Acute Care 17: Atrial Fibrillation/Atrial Flutter Algorithm
If unstable (shock, decreased LOC) and poor perfusion appears to be due to atrial fibrillation/atrial flutter with rapid ventricular response, perform immediate synchronized cardioversion. If stable, determine duration of atrial fibrillation/atrial flutter. If wide complex, consider Wolff-Parkinson-White syndrome.
Duration Less Than 48 Hours
Determine Cardiac Function:
| Heart
Function
Preserved: |
Impaired
Heart Function: (ie, CHF) |
 |
Control Ventricular Rate | |
|
Use only one agent of: |
Use one agent only: • Diltiazem (Class IIb) • Amiodarone (Class IIb) • Digoxin (Class IIb) |
|
Or (Less Commonly Used) |
|
Use
only one agent such as: |
•
Amiodarone (Class
IIb) • Digoxin (Class IIb) • Magnesium sulfate |
Methods of Converting Rhythm When Duration of AF Less Than 48 Hours
Consider conversion to NSR using medication or electrical cardioversion. Factors in this decision include level of comfort with sedation and potential airway management, need to avoid anticoagulation, and others. Consultation may be worthwhile.
|
|
|
|
Ventricular Function Preserved (EF > 40%) Ventricular Function Impaired (EF < 40%)
|
• DC cardioversion (Class I) |
• DC
cardioversion (Class I) or
• Amiodarone (Class IIa) |
Synchronized DC Cardioversion
Energy Levels:
Atrial Fibrillation: 120 J – 200 J Biphasic; 200 J Monophasic
Atrial Flutter: 50 J – 100 J
Duration More Than 48 Hours or
Unknown
Determine Cardiac Function:
| Heart Function Preserved: | Impaired
Heart Function: (ie, CHF) |
|
Control Ventricular Rate | |
| Use only one agent of: • Calcium channel blockers Diltiazem (Class I) • Beta blockers – Metoprolol (Class I) |
Use
only one agent: • Diltiazem (Class IIb) • Amiodarone (Class IIb) • Digoxin (Class IIb) |
| Avoid
Amiodarone, Procainamide, Flecainide, Propaferone if duration >48 hours (Class III) |
Methods of Converting Rhythm When Duration More Than 48 Hours
|
Caution Note: Avoid non-emergent cardioversion unless anticoagulation or clot precautions are taken. Urgent
Cardioversion: Delayed
Cardioversion: |
Wolff-Parkinson-White
(in Known WPW or Wide Complex Very Rapid
Atrial Fibrillation and Atrial Flutter)
Note:
In patients in atrial fibrillation/atrial flutter with an
accessory
pathway or WPW, the following drugs are Class III (can be harmful) and
should not be used as they may cause a paradoxical increase in the
ventricular rate.
• Adenosine
• Beta blockers
• Calcium channel blockers
• Digoxin
To Convert if Duration Less Than 48 Hours:
If the duration of the atrial fibrillation/atrial flutter with
WPW is
< 48 hours in duration:
• DC cardioversion is Class I or recommended treatment.
If drug therapy is used and ventricular function is preserved,
consider
the following Class II drug recommendations:
• Amiodarone
• Procainamide
• Flecainide
• Propafenerone
• Sotalol
If duration is 48 hours or less and the ventricular function
is
impaired:
• Use amiodarone only.
To Convert if Duration More Than 48 Hours:
Urgent Cardioversion:
|
Delayed Cardioversion:
|
Pharmacological Agents-Atrial Fibrillation-Atrial Flutter
Rate Control
Vagal
Maneuversa (Ice water or Valsalva
maneuver) or Adenosine
(6 to 12 mg
IV) temporarily slows the ventricular rate to confirm presence of
atrial flutter. In this
setting, vagal maneuvers and adenosine are used
for diagnostic purposes only.
Calcium Channel
Blockersa
Diltiazem:
0.25 mg/kg IV over 2 minutes. If ventricular rate does not slow in 15
minutes, give 2nd dose of 0.33 mg/kg IV over 2 minutes.
Verapamil: 5
mg IV over 2 minutes. If rate does not slow in 15
to 30
minutes, give 2nd dose of 5 to 10 mg over 2 minutes.
If
hypotension occurs with these agents, place patient in Trendelenburg
position or slowly infuse calcium chloride 0.5 to 1.0 g IV.
Beta Blockersa
Propanolol
(Inderal): 0.5 to 1.0 mg/min IV to maximum total
dose of 0.1
mg/kg.
Esmolol
(Brevibloc): Load with 0.5 mg/kg IV over 1 minute, then infuse 0.05 to
0.2 mg/kg/min IV as needed to slow the ventricular rate.
Metroprolol
(Lopressor): 5 mg IV over 2 to 5 minutes. Repeat
at
5-minute intervals to total dose of 15 mg.
Atenolol
(Tenormin): 5 mg IV over 5 min. May repeat in 10 min
to total
dose of 10 mg.
(Use extreme caution with use of beta blockers after use of
calcium
channel blockers.)
Digoxina (Lanoxin): Give 0.25 to 0.5 mg IV followed by 0.125 to 0.25 mg every 2 hours as needed to a maximum total dose of 0.75 to 1.5 mg (10 to 15 μg/kg) in the first 24 hours.
Chemical
Cardioversion
Ibutilide
(Corvert): (Class III anti-arrhythmic agent) Infuse 1 mg IV over 10
minutes. (For patients < 60 kg, use 0.01 mg/kg.) May repeat the
1 mg
infusion 10 minutes after completing the first infusion.
Propafenone
(Rythmol): (Class Ic anti-arrhythmic agent) Initial dose of 150 mg PO
every 8 hours; may increase every 3 to 4 days up to 300 mg every 8
hours.
Amiodarone
(Cordarone): (Class III anti-arrhythmic agent)
Load with 800 to 1000 mg per day PO for 1 to 3 weeks, then 400 to 800
mg per day for 2 to 4 weeks, then 100 to 400 mg per day as maintenance.
Sotalol
(Betapace): (Class II and III anti-arrhythmic agent) Initial dose of 80
mg bid PO; increase to a maximum total daily dose of 320 mg/day.
Flecainide
(Class Ic anti-arrhythmic agent) Load with 2 mg/kg IV slow infusion at
rate up to 10 mg/min. Must
be infused slowly. (IV form not approved in
the US)
Procainamide
(Class Ia anti-arrhythmic agent) Loading dose of
20 to 30
mg/min IV to max of 17 mg/kg.
Anticoagulants: Heparin, Enoxaparin (Lovenox), Warfarin (Coumadin), and Dabigatran (Pradexa).
Caution: If any of these agents are used for treatment of patients with atrial fibrillation or atrial flutter, monitor the patient while observing for prolongation of the QT interval. This may indicate that the patient is at risk for developing a serious arrhythmia. If this happens, consider discontinuing the offending drug.