New Onset Atrial Fibrillation Part 4
Unstable Patient
Control
rate
© Diltiazem:
0.25mg/kg over 2 minutes. If
ineffective, in 15 minutes may repeat 0.35mg/kg over 2 minutes. Followed by a maintenance infusion of
5-15mg/hr*
© Amiodarone
(IIb) 150 mg given over 10 minutes and repeated if necessary, followed by a 1
mg/min infusion for 6 hours, followed by 0.5 mg/min. Total dose over 24 hours
should not exceed 2.2 g.* Observe for bradycardia and hypotension.
©
Digoxin (class IIb) Digoxin 8 to 12 mcg/kg total
loading dose, half of which is administered initially over 5 minutes, and
remaining portion as 25% fractions at 4- to 8- hour intervals*
Convert
rhythm
© Synchronized
cardioversion
© Pharmacologic
cardioversion
Synchronized
cardioversion
© Atrial
flutter- 50J, and increase as needed
© Atrial
fibrillation- 120 - 200J, and increase as needed
Note: When acute AF
produces hemodynamic instability in the form of angina pectoris, MI, shock, or
pulmonary edema, immediate cardioversion should not be delayed to deliver
therapeutic anticoagulation, but intravenous unfractionated heparin or
subcutaneous injection of a low-molecular-weight heparin should be initiated
before cardioversion by direct-current countershock or intravenous
antiarrhythmic medication.
Direct-current cardioversion involves delivery of an
electrical shock synchronized with the intrinsic activity of the heart by
sensing the R wave of the ECG to ensure that electrical stimulation does not
occur during the vulnerable phase of the cardiac cycle. Direct-current
cardioversion is used to normalize all abnormal cardiac rhythms except
ventricular fibrillation.
Pharmacologic
cardioversion
© Amiodarone
(IIb) 150 mg given over 10 minutes and repeated if necessary, followed by a 1
mg/min infusion for 6 hours, followed by 0.5 mg/min. Total dose over 24 hours
should not exceed 2.2 g.*
© Observe
for bradycardia and hypotension
Emboli
Preventing
Thromboembolism
Antithrombotic therapy to prevent thromboembolism is
recommended for all patients with AF, except those with lone AF or contraindications.
(Level of Evidence: A)
Preventing
Thromboembolism
For patients with AF of < 48-hours duration associated
with hemodynamic instability, immediate cardioversion should be performed
without anticoagulation.
(Level of Evidence: C)
Preventing
Thromboembolism
As an alternative to anticoagulation prior to cardioversion
of AF, it is reasonable to perform transesophageal echocardiography in search
of thrombus. (Level of Evidence: B)
Preventing
Thromboembolism
For patients with AF of more than 48-h duration requiring
immediate cardioversion because of hemodynamic instability, heparin should be
administered concurrently by an initial intravenous injection followed by a
continuous infusion (aPTT 1.5 to 2 times control).
Preventing
Thromboembolism
Thereafter, oral anticoagulation (INR 2.0 to 3.0) should be
provided for at least 4 weeks, as for elective cardioversion. Limited data support subcutaneous
low-molecular-weight
heparin. (Level of Evidence: C)
Preventing
Thromboembolism
The antithrombotic agent should be chosen based upon the
absolute risks of stroke and bleeding and the relative risk and benefit for a
given patient. (Level of Evidence: A)
References
Aehlert, Barbara. ACLS Quick Review Study Guide, 2nd
edition. Mosby, inc. St. Louis, Mo. 1994.
Cummings, Richard, ed. ACLS Provider Manual. American Heart
Association. 7272 Greenville Ave. Dallas, TX. 2001.
References
*Neumar et al, “Part 8: Adult Advanced Cardiovascular Life
Support: 2010 American Heart Association Guidelines for Cardiopulmonary
Resuscitation and Emergency Cardiovascular Care, November 2, 2010, issue of the
journal (Circulation. 2010;122[suppl 3]:S729 –S767)
References
***Fuster V, Rydén LE, Cannom DS, Crijns HJ, Curtis AB,
Ellenbogen KA, Halperin JL, Le Heuzey J-Y, Kay GN, Lowe JE, Olsson SB,
Prystowsky EN, Tamargo JL, Wann S, Smith SC Jr, Jacobs AK, Adams CD, Anderson
JL, Antman EM, Hunt SA, Nishimura R, Ornato JP, Page RL, Riegel B, Priori SG, Blanc
J-J, Budaj A, Camm AJ, Dean V, Deckers JW, Despres C, Dickstein K, Lekakis J,
McGregor K, Metra M, Morais J, Osterspey A, Zamorano JL. ACC/AHA/ESC 2006
guidelines for the management of patients with atrial fibrillation—executive
summary: a report of the American College of Cardiology/American Heart
Association Task Force on Practice Guidelines and the European Society of
Cardiology Committee for Practice Guidelines (Writing Committee to Revise the
2001 Guidelines for the Management of Patients With Atrial Fibrillation).
Circulation. 2006;114:700-752.
References
**ACCF/AHA Pocket Guideline
Management of Patients With Atrial Fibrillation
(Adapted from the 2006 ACC/AHA/ESC Guideline and the
2011 ACCF/AHA/HRS Focused Updates)
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