ACLS: Tachycardia

This page is for adult patients; for pediatric patients see PALS: Tachycardia

3 questions

Algorithm for tachycardia with a pulse[1]
  1. Is the patient in a sinus rhythm?
  2. Is the QRS wide or narrow?
  3. Is the rhythm regular or irregular?

Narrow-complex tachycardia

Narrow Regular Tachycardia

  • Sinus tachycardia
    • Treat underlying cause
  • SVT
    • Vagal maneuvers (convert up to 25%)
    • Adenosine 6mg rapid IV push if patient hemodynamically stable (unstable should proceed directly to electrical cardioversion)
      • Can follow with repeat dose of 6 mg or 12mg if initially fails
      • If adenosine fails, initiate rate control with calcium channel blocker or beta blocker or use synchronized cardioversion
        • Diltiazem 15-20mg IV, followed by infusion of 5-15mg/hr
        • Metoprolol 5mg IVP x 3 followed by 50mg PO
    • Synchronized cardioversion (50-100J)
      • Provide sedation prior to synchronized cardioversion if patient is hemodynamically stable
  • Atrial flutter
    • Stable: Consider rate control to HR < 110 bpm
    • Unstable: Synchronized cardioversion; start at 50J

Narrow Irregular Tachycardia

  • Multi-focal atrial tachycardia (MAT)
    • Treat underlying cause (hypokalemia, hypomagnesemia)
    • Consider diltiazem
    • Avoid beta blockers unless they are already known to be tolerated, as airway disease often co-morbid
    • If not symptomatic and rate < 110/120 bpm, may not require treatment (e.g., patient with MAT secondary to COPD)
  • Sinus Tachycardia with frequent PACs
    • Treat underlying cause
  • A fib / A Flutter with variable conduction (see also Atrial Fibrillation with RVR)
    • Check if patient has taken usual rate-control meds
      • If missed dose, may provide dose of home medication and observe for resolution
    • Determine whether patient is better candidate for rate control or rhythm control [2]
      • Rate control preferred with:
        • Persistent A fib
        • Less symptomatic patients
        • Age 65 or older
        • Hypertension
        • No heart failure
        • Previous failure to cardiovert
        • Patient preference
      • Rhythm control preferred with:
        • Paroxismal or new A fib
        • More symptomatic patients
        • Age < 65 years
        • Heart failure clearly exacerbated by A fib
        • No history of rhythm control failure
        • Patient preference
    • Rate control with:
    • Rhythm conversion with:

Wide-complex tachycardia

Wide Regular Tachycardia[3]

Pulseless: see Adult pulseless arrest

  • Unstable: Hypotension, altered mental status, shock, ischemic chest discomfort, acute heart failure
  • Stable:
  • Medications
    • Procainamide (first-line drug of choice)
      • 20-50mg/min until arrhythmia suppressed (max 17mg/kg or 1 gram); then, maintenance infusion of 1-4mg/min x 6hr
        • Alternative administration: 100 mg q5min at max rate of 25-50 mg/min[4]
      • Stop if QRS duration increases >50% or hypotension
      • Avoid if prolonged QT or CHF
      • Favored over Amiodarone in PROCAMIO trial; termination of tachycardia in 67% of procainamide group vs 38% of amiodarone group, adverse cardiac events 9% vs 41%, respectively [5]
    • Amiodarone (agent of choice in setting of AMI or LV dysfunction)
      • 150 mg over 10min (15 mg/min), followed by 1 mg/min drip over 6hrs (360 mg total)[6]
      • Then 0.5 mg/min drip over next 18 hrs (540 mg total)
      • Oral dosage after IV infusion is 400 -800 mg PO daily
    • Consider adenosine
    • Synchronized Cardioversion (100J)

Wide Irregular Tachycardia

DO NOT use AV nodal blockers as they can precipitate V-Fib
Pulseless: see Adult pulseless arrest

Differential Diagnosis

Narrow-complex tachycardia

Wide-complex tachycardia

Assume any wide-complex tachycardia is ventricular tachycardia until proven otherwise (it is safer to incorrectly assume a ventricular dysrhythmia than supraventricular tachycardia with abberancy)

^Fixed or rate-related

See Also

External Links


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  1. Adapted from ACLS 2010
  2. Frankel, G. et al. (2013) Rate versus rhythm control in atrial fibrillation. Canadian Family Physician 59(2), 161 - 168
  3. American Heart Association. Web-based Integrated Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care – Part 7: Adult Advanced Cardiovascular Life Support.
  4. Procainamide. GlobalRPH.
  5. Ortiz M, Martín A, Arribas F, et al. Randomized comparison of intravenous procainamide vs. intravenous amiodarone for the acute treatment of tolerated wide QRS tachycardia: the PROCAMIO study. Eur Heart J. 2017 May 1;38(17):1329-1335
  6. Amiodarone. GlobalRPH.