ACLS Tachycardia Algorithm for Managing Stable Tachycardia

Last updated: December 20, 2020

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Using the ACLS tachycardia algorithm for managing stable tachycardia

The steps to managing a patient with any tachycardia is to assess if pulses are present, decide if the patient is stable or unstable, and then treat the patient based on the patient's condition and rhythm. If the patient does not have a pulse, follow the ACLS Pulseless Arrest Algorithm. If the patient has a pulse, manage the patient using the ACLS Tachycardia Algorithm.

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Definition of stable tachycardia

A patient is diagnosed of stable tachycardia if the patient meets the following criteria:

  • The patient's heart rate is greater than 100 bpm.
  • The patient does not have any serious signs or symptoms as a result of the increased heart rate.
  • The patient has an underlying cardiac electrical abnormality that is generating the arrhythmia.


Find out if significant symptoms are present. Evaluate the symptoms and decide if they are caused by the tachycardia or other systemic conditions. Use these questions to guide your assessment:

  • Does the patient have symptoms?
  • Is the tachycardia causing the symptoms?
  • Is the patient stable or unstable?
  • Is the QRS complex narrow or wide?
  • Is the rhythm regular or irregular?
  • Is the rhythm sinus tachycardia?


Situation Assessment and actions

Patient has significant signs or symptoms of tachycardia AND they are being caused by the arrhythmia.

The tachycardia is unstable. Immediate cardioversion is indicated.

Patient has pulseless ventricular tachycardia.

Follow the Pulseless Arrest Algorithm. Deliver unsynchronized high-energy shocks.

Patient has polymorphic ventricular tachycardia AND the patient is unstable.

Treat the rhythm as ventricular fibrillation. Deliver unsynchronized high-energy shocks.

Steps for managing stable tachycardia

Does the patient have a pulse?

Yes, the patient has a pulse. Complete the following:

  1. Assess the patient using the primary and secondary surveys.
  2. Check the airway, breathing, and circulation
  3. Give oxygen and monitor oxygen saturation.
  4. Get an ECG.
  5. Identify rhythm.
  6. Check blood pressure.
  7. Identify and treat reversible causes.

Is the patient stable?

Look for altered mental status, ongoing chest pain, hypotension, or other signs of shock.

Remember: Rate-related symptoms are uncommon if heart rate is < 150 bpm.

Yes, the patient is stable. Take the following actions:

  1. Start an IV.
  2. Obtain a 12-lead ECG or rhythm strip.

Is the QRS complex wide or narrow?

Patient Treatment

The patient's QRS is narrow and rhythm is regular.

Try vagal maneuvers. Give adenosine 6 mg rapid IV push. If the patient does not convert, give adenosine 12 mg rapid IV push. May repeat 12 mg dose of adenosine once.

Does the patient's rhythm convert? If it does, it was probably reentry supraventricular tachycardia. At this point you need to watch for a recurrence. If the tachycardia resumes, treat with adenosine or longer-acting AV nodal blocking agents, such as diltiazem or beta-blockers.

Patient Treatment

The patient's QRS is narrow (< 0.12 sec).

Consider an expert consultation.

The patient's rhythm is irregular.

Control patient's rate with diltiazem or beta-blockers. Use beta-blockers with caution for patients with pulmonary disease or congestive heart failure.

If the rhythm pattern is irregular narrow-complex tachycardia, it is probably atrial fibrillation, possible atrial flutter, or multifocal atrial tachycardia.

Patient Treatment

Patient's rhythm has wide (> 0.12 sec) QRS complex AND Patient's rhythm is regular.

Expert consultation is advised.

Patient is in ventricular tachycardia or uncertain rhythm.

Amiodarone 150 mg IV over 10 min; repeat as needed to maximum dose of 2.2 g in 24 hours. Prepare for elective synchronized cardioversion.

Patient is in supraventricular tachycardia with aberrancy.

Adenosine 6 mg rapid IV push If no conversion, give adenosine 12 mg rapid IV push; may repeat 12 mg dose once.

Patient's rhythm has wide (> 0.12) QRS complex AND Patient's rhythm is irregular.

Seek expert consultation.

If pre-excited atrial fibrillation (Atrial fibrillation in Wolff-Parkinson-White Syndrome)

Avoid AV nodal blocking agents such as adenosine, digoxin, diltiazem, verapamil. Consider amiodarone 150 mg IV over 10 min.

Patient has recurrent polymorphic VT

Seek expert consultation,

If patient has torsades de pointes rhythm on ECG

Give magnesium (load with 1–2 g over 5–60 min; then infuse.

Caution: If the tachycardia has a wide-complex QRS and is stable, consult with an expert. Management and treatment for a stable tachycardia with a wide QRS complex and either a regular or irregular rhythm should be done in the hospital setting with expert consultation available. Management requires advanced knowledge of ECG and rhythm interpretation and antiarrhythmic therapy.


  • You may not be able to distinguish between a supraventricular wide-complex rhythm and a ventricular wide-complex rhythm. Most wide-complex tachycardias originate in the ventricles.
  • If the patient becomes unstable, proceed immediately to treatment. Do not delay while you try to analyze the rhythm.
  • If the patient becomes unstable, proceed immediately to treatment. Do not delay while you try to analyze the rhythm.

Note: Visit this page to get information on cardiac arrhythmias in Spanish.

This page is written by on Sep 18, 2018.
This page is last reviewed and updated by on Jun 4, 2020.