Cardinal Features

The cardinal features of polymorphic VT (Fig 1) are:

  1. QRS rate is rapid (200–250 bpm)
  2. Amplitude of the QRS complexes change in a sinusoidal fashion
  3. Usually self-limiting but may be recurrent

Fig 1: Polymorphic ventricular tachycardias

Polymorphic VT is uncommon and rarely sustained.