Medic Basics

Cardiac arrest and ACLS

Tachycardia With a Pulse Algorithm

Unstable vs stable, narrow vs wide

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

Each step lists what to do, then the choices that lead on. In the app the algorithm is tapped through one decision at a time.

1 Is the tachycardia causing instability?

  • Usually HR 150 or more when the rhythm is the cause
  • Hypotension, altered mental status, shock, chest pain, acute heart failure

Unstable → step 2Stable → step 3

2 Synchronized cardioversion

  • Sedate if possible
  • AF: 200 J or more biphasic; atrial flutter: 200 J (AHA 2025)
  • Other regular narrow-complex: 100 J
  • Wide regular (monomorphic VT): 100 J
  • Raise the energy if a shock fails
  • Wide irregular or polymorphic: defibrillate (unsynchronized)

End of this path.

3 Is the QRS wide (0.12 s or more)?

Narrow → step 4Wide → step 5

4 Narrow QRS

  • Regular: vagal maneuvers, then adenosine 6 mg rapid IV push with flush, then 12 mg
  • Beta-blocker or calcium channel blocker for rate control
  • Irregular (AF): rate control; anticoagulation decisions

End of this path.

5 Wide QRS

  • Regular and monomorphic: adenosine is an option
  • Antiarrhythmic: procainamide, amiodarone 150 mg over 10 minutes, or sotalol
  • Expert consultation

End of this path.

Drugs in this algorithm

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