Characterization of repolarization in Brugada syndrome patients during exercise testing: Dynamic angle evaluation

Area of Science:

• Cardiology
• Electrocardiography
• Medical Diagnostics

Background:

• Brugada syndrome (BrS) requires accurate differentiation from incomplete right bundle branch block (IRBBB).
• A novel electrocardiogram (ECG) criterion, the beta angle, has been investigated for this purpose.

Purpose of the Study:

• To evaluate the efficacy of the beta angle in distinguishing BrS from IRBBB.
• To assess the beta angle's behavior during exercise and recovery in both conditions.

Main Methods:

• The study involved 46 patients with BrS and 17 with IRBBB.
• A beta angle was measured from lead V1, analyzing the S-wave upslope and r'-wave downslope.
• Measurements were taken at rest, during exercise, and during recovery.

Main Results:

• The beta angle was significantly larger in BrS patients compared to IRBBB patients at rest, during exercise, and recovery (p<0.001).
• A reduction in the beta angle was observed during exercise in both groups.
• A significant recovery rebound of the beta angle occurred in the control group (IRBBB), but not in the BrS group.

Conclusions:

• The beta angle measured at rest and its dynamic changes during exercise can aid in discriminating BrS patients.
• This ECG criterion shows potential for non-invasive diagnosis of Brugada syndrome.