Brugada Algorithm for Differentiating VT from SVT
The Brugada Algorithm is for differentiation: Is this Ventricular Tachycardia or just Supraventricular Tachycardia with “aberrancy” (like a bundle branch block)?
You follow these 4 steps in order. If you answer YES to any step, the diagnosis is VT.
| Step | Criteria | Significance |
| 1 | Absence of RS complex in all precordial leads (V1-V6)? | This is “concordance.” If all leads are entirely positive (R) or entirely negative (QS), it’s VT. |
| 2 | RS interval > 100ms in any precordial lead? | Measure from the start of the R wave to the deepest part (nadir) of the S wave. If >100ms, it’s VT. |
| 3 | Atrioventricular (AV) Dissociation? | Look for P waves “marching” independently of the QRS. This is a “smoking gun” for VT. |
| 4 | Morphology Criteria for VT? | Specific “classic” VT shapes (e.g., “Left Rabbit Ear” taller than the right in V1). |
Reference
- Brugada P, Brugada J, Mont L, Smeets J, Andries EW. A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex. Circulation. 1991 May;83(5):1649-59. doi: 10.1161/01.cir.83.5.1649. PMID: 2022022.
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About The Author
Johnson Francis
Former Professor of Cardiology, Calicut Govt. Medical Kozhikode, Kerala, India. Editor-in-Chief, BMH Medical Journal