Back to Basics: Approach to Atrial Fibrillation w RVR

Approach to Atrial Fibrillation with RVR

First Question: Stable or Unstable?

-Unstable = hypotension (SBP < 90), AMS, ischemic chest pain, acute pulmonary edema

-If unstable: electrical synchronized cardioversion at 200 J. Use sedation!

-If stable: rate vs rhythm control

Before slowing the rate, consider why they are in Afib, and if that elevated HR is a compensatory mechanism. However, once the rate is >140-150, decreased diastolic filling time results in decreased CO, so it may be beneficial to slow them down. Some precipitants of acute onset Afib: EtOH, thyrotoxicosis, MI, PE, infection, illicit drugs

Rate Control

-Rate control increases the diastolic filling time, increasing CO

-Many drugs available

– good to know many options in times of shortage


AV nodal blocker

10-20 mg IV bolus over 2 min (0.25 mg/kg)

Start a drip: 2.5-15 mg/hr, titrate until rate controlled If hypotensive, consider pre-treating with 1 gram IV calcium gluconate to decrease peripheral hypotension, though controversial


AV nodal blocker

5 mg IV bolus over 2 min, every 5 min to max dose of 15 mg

Start on PO (25-100 mg)

Drug of choice if hyperthyroid, but CI in COPD, asthma, acute CHF


AV nodal blocker

0.25-0.5 mg IV, can repeat after 6-8 hours.

Max 1.5 mg/24 hours


AV nodal blocker

500 mcg/kg IV bolus over 1 minute

Infusion 50-300 mcg/kg/min IV, titrated to heart rate

Fast onset and offset


AV nodal blocker

2.5-5 mg IV bolus over 2-3 minutes

If persists, can repeat dose of 5-10 mg

Monitor BP as this can cause significant hypotension! Consider pre-treatment with calcium

Rhythm Control

Two options: Electricity or pharmacologic.

If electrical, see above


2 grams IV over 2 minutes, followed by infusion 1-2 g/hr


Class III antiarrhythmic

150 mg IV over 10 minutes

Then drip 1 mg/min for 6 hours, then 0.5 mg/min

Initially slows the rate (like beta blocker effect), and rhythm control takes some time


Class 1a antiar rhythmic

15-17 mg/kg IV over 30 min, followed by drip 1-4 mg/min

Use in WPW because also blocks the accessory pathway

Special Consideration:

-If fast Afib (rate in high 100s-200), think accessory pathway like WPW and do NOT block the AV node as that can lead to degeneration into VF. Use procainamide


Tintinalli, Judith, et al. “Cardiac rhythm disturbances and pharmacology of antihypertensives and antiarrhythmics. ” Tintinalli’s Emergency Medicine, 8th ed., McGrath-Hill, 2016. pp 112 - 142.