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Brugada-Stuerer Algorithm (VT vs. Pre-Excited SVT)

Brugada Stuerer algorithm (ventricular tachycardia vs. pre-excited SVT)

Modified Brugada Algorithm (VT vs. Preexcitation SVT)

• Diagnostic Algorithms cannot differentiate wide complex tachycardia
• Distinguish between ventricular tachycardia and preexcitation SVT (Antidromic AVRT)
• To differentiate VT and preexcitation SVT (PXT)
• The modified Brugada algorithm was created
• In practice, it is used significantly less than the classic Brugada Algorithm

Wide Complex Tachycardia

• Modified Brugada Algorithm differentiates the mechanism of wide complex tachycardia
• It distinguishes ventricular tachycardia (VT) from Preexcitation SVT (PXT)
• It is the only algorithm capable of this differentiation

Modified Brugada Algorithm (VT vs. PXT)

• 1. Negative QRS (V4-V6)?
• Preexcitation SVT has an accessory pathway at the base of the ventricles
• The vector therefore points TOWARD the apex in V4-V6
• Hence, the QRS will be positive in (V4-V6) for preexcitation SVT
• 2. At least 1 QR configuration (V2-V6)?
• QR configuration primarily occurs in structurally altered ventricles
• In structurally altered ventricles, ventricular tachycardia almost always occurs
• 3. AV conduction different from 1:1?
• Preexcitation SVT always has 1:1 AV conduction
• If the conduction is different, it is VT (analogous to AV dissociation)
  
  
• If none of the 3 ECG criteria are met
• Then the wide-complex tachycardia is preexcitation SVT (Antidromic AVRT)

Wide-Complex Tachycardia

• QRS Width 0.2s
• Heart Rate 200/min.
• The patient has WPW Syndrome
• On the ECG during sinus rhythm, there was a delta wave
• Modified Brugada Algorithm
• 1st Condition: Is QRS Negative (V4-V6) - NO
• The QRS is positive in V4
• 2. At least 1 QR (V2-V6) - NO
• 3. AV conduction different from 1:1 - NO
• The patient has preexcitation SVT (Antidromic AVRT)
• This is confirmed by the fact that during sinus rhythm, there is a delta wave

WPW Syndrome (Type B)

• This is the ECG from the previous patient after conversion to sinus rhythm
• This is WPW Syndrome (Type B)
• Shortened PQ interval
• Borderline widened QRS (120ms)
• Delta waves
• Accessory pathway is in the right atrium
• The patient has an accessory pathway (WPW Syndrome)
• On the previous ECG, there was Antidromic AVRT