A new criteria differentiating type 2 and 3 Brugada patterns from ordinary incomplete right bundle branch block

Area of Science:

• Cardiology
• Electrophysiology
• Medical Diagnostics

Background:

• Brugada syndrome (BrS) is diagnosed by specific ECG patterns, with Type 1 being diagnostic.
• Types 2 and 3 Brugada ECG patterns require drug challenge for confirmation.
• Differentiating true Brugada ECG patterns from incomplete right bundle branch block (iRBBB) can be challenging.

Purpose of the Study:

• To evaluate a novel 12-lead ECG criterion for distinguishing iRBBB from Brugada ECG Types 2 and 3.
• To assess if a specific ECG angle measurement can predict response to antiarrhythmic drug challenge in Brugada syndrome diagnosis.

Main Methods:

• A study involving 22 patients undergoing antiarrhythmic drug challenge (pilsicainide).
• Measurement of the baseline angle in ECG leads V1 and/or V2 for patients with iRBBB pattern.
• Comparison of the baseline angle between patients who responded positively and negatively to the drug challenge.

Main Results:

• The baseline angle was significantly smaller in patients who did not develop a Type 1 Brugada ECG pattern (20.9° vs. 38.7°, P = 0.009).
• This ECG measurement effectively discriminated between ordinary iRBBB and drug-induced Brugada ECG evolution.
• The method showed potential for improved Brugada syndrome diagnosis.

Conclusions:

• A specific baseline angle measurement in leads V1/V2 can differentiate iRBBB from evolving Brugada ECG patterns.
• This ECG-based criterion aids in the diagnosis of Brugada syndrome by identifying subtle Type 2 and 3 patterns.
• The findings suggest a valuable tool for Brugada syndrome diagnosis in clinical practice.