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

- Beta angle and base of the triangle are new geometrical criteria for Brugada pattern.
- These criteria had never been studied during exercise.
- We compared BrS patients and IRBBB patients during exercise.
- The two criteria were significantly larger in BrS at rest, exercise and recovery.
- There was a significant rebound in angle at recovery in controls contrary to BrS.

BackgroundA new ECG criterion has been studied in Brugada syndrome (BrS) at rest to differentiate type 2 and incomplete right bundle branch block (IRBBB).MethodsWe assessed this criterion during exercise comparing BrS (46 patients) and IRBBB (17 patients). A beta angle was measured from lead V1 between the upslope of S-wave and the downslope of the r'-wave.ResultsBeta angle was significantly larger in BrS at rest (58 ± 24° vs 25 ± 15°, p < 0.001), exercise (47 ± 26° vs 15 ± 11°, p < 0.001), and recovery (46 ± 24° vs 21 ± 12°, p < 0.001) with a reduction in angle at exercise compared to rest. There was a significant rebound in angle at recovery in the control group to (p < 0.001); no such rebound was observed in the BrS group (p = NS).ConclusionBeta angle study at rest and its evolution at exercise could help discriminate BrS patients from healthy subjects.

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