Ventricular Tachycardia

Ventricular Tachycardia is a topic covered in the 5-Minute Emergency Consult.

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  • A wide complex tachydysrhythmia with a quasirandom signal (QRS) >120 and a rate >100
  • Rapid and regular depolarization of the ventricles independent of the atria and the normal conduction system
  • Re-entry:
    • Structural heart disease most common
    • Seen in dilated cardiomyopathy, ischemia, and infiltrative heart disease, previous MI, scarring
    • May be pharmacologically induced
    • Usually produces a regular and monomorphic rhythm
  • Triggered automaticity:
    • Minority of ventricular tachycardia (VT)
    • Caused by repetitive firing of a ventricular focus
  • Torsades de pointes:
    • Polymorphic form of VT
    • Alternating electrical polarity and amplitude
    • Prolongation in repolarization necessary
    • Usually pharmacologically induced
  • Regardless of the mechanism, all VT may degenerate to ventricular fibrillation (VF).


  • Wide complex tachycardia:
    • 80% likelihood of being VT
    • 20% supraventricular tachycardia (SVT) with a baseline left bundle branch block (LBBB) or aberrancy
  • Wide complex tachycardia and a history of MI:
    • >98% likelihood of being VT
    • Age >35: 80% risk of VT
    • Age <35: 75% risk of SVT
  • Incidence of nonsustained VT:
    • 0–4% in the general population
    • Up to 60% of patients with dilated cardiomyopathy
  • Associated with increased risk for sudden cardiac death (SCD)

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