Wide-complex tachycardia


  • 3 wide complexes in a row is considered ventricular tachycardia
    • Non-sustained if lasts < 30 seconds
    • Sustained if lasts >30 seconds


  • Due to true ventricular tachycardia in 80% of cases
    • For patients with underlying cardiac disease, increases to > 90%
  • Consider:

Clinical Features

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


Ventricular tachycardia


Wide Regular Tachycardia[4]

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[5]
      • 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 [6]
    • 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)[7]
      • 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


  • ≥3 episodes within 24 hours considered electrical storm and may require alternate treatment (i.e. beta blockade, sedation, ablation)

Other considerations

  • True Vtach generally has rate >120bpm. If rate <120bpm or refractory to other therapy, consider other causes
  • When in doubt, use cardioversion for treatment of regular WCT. In irregular WCT, consider Afib with WPW in which Procainamide is the treatment of choice
  • In very wide complex (>0.2 msec) and <120 bpm in a patient with significant history, consider giving calcium chloride to treat hyperkalemia
  • Consider Acidosis
  • Sodium channel blockade (e.g. from benadryl, TCA, or cocaine toxicity) may cause very wide complex (>0.2msec) tachycardia with rate <120bpm


  • Admit all patients (even if converted to normal sinus rhythm in ED)

See Also

External Links


  1. Gupta AK, Thakur RK. Wide QRS complex tachycardias. Med Clin North Am. 2001;85(2):245–66– ix–x.
  2. Akhtar M, Shenasa M, Jazayeri M, Caceres J, Tchou PJ. Wide QRS complex tachycardia. Reappraisal of a common clinical problem. Ann Intern Med. 1988;109(11):905–912.
  3. Stewart RB, Bardy GH, Greene HL. Wide complex tachycardia: misdiagnosis and outcome after emergent therapy. Ann Intern Med. 1986;104(6):766–771.
  4. American Heart Association. Web-based Integrated Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care – Part 7: Adult Advanced Cardiovascular Life Support. ECCguidelines.heart.org
  5. Procainamide. GlobalRPH. http://www.globalrph.com/procainamide_dilution.htm.
  6. 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
  7. Amiodarone. GlobalRPH. http://www.globalrph.com/amiodarone_dilution.htm.