Management of Atrial Fibrillation in the Acutely Ill

• In the acutely ill patient with rapid Afib, management should focus on quick rate control
• IV diltiazem should be the treatment of choice
• Bolus is crucial; re-bolus is crucial – they brake the vicious cycle of fast ventricular rate, reduced LV filling, reduced stroke volume, all resulting in further adrenergic activation
• Diltiazem drip does not reduce the heart rate; it maintains whatever you achieved with the bolus
• Never order “diltiazem drip, titrate to heart rate”
• Ideal dose of initial diltiazem bolus is 0.25 mg/kg over 2 minutes
• Ideal dose of re-bolus is 0.35 mg/kg over 2 minutes
• Marked hypotension may limit giving the optimum doses of diltiazem boluses
• Under these circumstances, there are several options for pre-treatment before the IV diltiazem bolus
  • IV fluid boluses
  • IV digoxin, 0.5 mg
  • Phenylephrine, 100-300 mcg IV push over 10-30 sec
• With the help of one or more of the above, IV diltiazem can almost always be given safely
• Consider IV beta blocker (esmolol) instead of diltiazem for patients with rapid Afib and acute MI, ongoing ischemia, thyrotoxicosis and HOCM crisis
• IV amiodarone is almost never needed for rate control
• If rate control is still inadequate despite maximum tolerated doses of diltiazem, adding 0.5 mg of IV digoxin will frequently “finish the job”
• For critically ill patients with rapid Afib, consider emergent cardioversion
• Do not shock the patient with MAT or with repetitive Afib characterized by the presence of occasional sinus complexes
• These patients are frequently good candidates for rhythm management with amiodarone or beta blocker

 

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