17. Diagnosis of Wide-Complex Tachycardia (VT vs SVT, Brugada Criteria)

  1. Is there absence of an RS complex in all of the precordial leads (V1-V6)? If yes, diagnosis = VT (stop).
  2. Is there AV dissociation or V-A block? If yes, diagnosis = VT (stop).
  3. Is there a capture or fusion beat?  If yes, diagnosis = VT (stop).
  4. Is the R to S interval (beginning of R to nadir of S) > 100 msec in any one of the precordial leads? If yes, diagnosis = VT (stop).
  • Note: antiarrhythmic drugs may give a false positive diagnosis of VT, under this criterion.
  1. Determine if there is a RBBB- or LBBB-type pattern to the wide complex tachycardia. 
  • RBBB-type QRS pattern: must have one waveform from both V1 and V6 to diagnose VT:

     6. Are there morphologic criteria for VT present? If yes, diagnosis = VT (stop).

  • RBBB-type QRS pattern: dominant positive in V1.
  • LBBB-type QRS pattern: dominant negative in V1.

  • LBBB-type QRS pattern: can meet any of the following criteria to diagnose VT:

Brugada P, Brugada J, Mont L, et al. A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex. Circulation. 1991;83:1649-1659.