Thomas Pospiech1, Jérémie Jaussaud2, Frédéric Sacher3, Darren A Hooks4, Michel Haïssaguerre3, Hervé Douard5. 1. Dept of Rehabilitation and Coronary Disease, University Hospital of Bordeaux, Pessac, France. Electronic address: thomas.pospiech@u-bordeaux.fr. 2. Dept of Rehabilitation and Coronary Disease, University Hospital of Bordeaux, Pessac, France; Division of Cardiology, Sport Clinic of Bordeaux, Merignac, France. 3. Dept of Electrophysiology, University Hospital of Bordeaux, LYRIC, Pessac, France. 4. Bioengineering Institute, University of Auckland, Private Bag, Auckland, New Zealand. 5. Dept of Rehabilitation and Coronary Disease, University Hospital of Bordeaux, Pessac, France.
Abstract
BACKGROUND: A new ECG criterion has been studied in Brugada syndrome (BrS) at rest to differentiate type 2 and incomplete right bundle branch block (IRBBB). METHODS: We 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. RESULTS: Beta 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). CONCLUSION: Beta angle study at rest and its evolution at exercise could help discriminate BrS patients from healthy subjects.
BACKGROUND: A new ECG criterion has been studied in Brugada syndrome (BrS) at rest to differentiate type 2 and incomplete right bundle branch block (IRBBB). METHODS: We 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. RESULTS: Beta 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). CONCLUSION: Beta angle study at rest and its evolution at exercise could help discriminate BrS patients from healthy subjects.