Do patients with electrocardiographic Brugada type 1 pattern have associated right bundle branch block? A comparative...

Area of Science:

• Cardiology
• Electrophysiology
• Medical Diagnostics

Background:

• Brugada syndrome is associated with right bundle branch block (RBBB) on electrocardiograms (ECGs).
• Previous ECG analyses indicated that some RBBB classifications in Brugada syndrome lack specific criteria.
• The diagnostic utility of vectorcardiography for Brugada type 1 ECG patterns requires further investigation.

Purpose of the Study:

• To investigate the role of vectorcardiography in characterizing the Brugada type 1 ECG pattern.
• To differentiate Brugada type 1 ECG patterns from incomplete RBBB (IRBBB) and complete RBBB (CRBBB) using vectorcardiography.

Main Methods:

• Frank-method vectorcardiograms were analyzed in 11 patients with Brugada type 1 ECG (BrS group).
• Comparison was made with vectorcardiograms from 20 healthy individuals with IRBBB and 12 patients with CRBBB.
• Key parameters analyzed included QRS loop characteristics, spatial location of conduction delay, and T loop morphology.

Main Results:

• The initial QRS vector in the horizontal plane was anterior and leftward in BrS and IRBBB groups, versus anterior and rightward in the CRBBB group.
• End conduction delay in the BrS group localized to the upper right frontal and right posterior horizontal planes.
• T loops in the BrS group were circular and symmetrical, unlike the elliptical or linear T loops in the IRBBB and CRBBB groups.

Conclusions:

• Vectorcardiograms exhibit unique features in Brugada type 1 ECG patterns compared to IRBBB and CRBBB.
• Distinctive spatial localization of conduction delay and T loop morphology (circular, symmetrical) characterize Brugada type 1.
• These vectorcardiographic findings enhance the characterization of Brugada type 1 ECG patterns.