Most physicians are aware of the Brugada Syndrome cardiac repolarization phenotype – the most recognizable being Type 1, or “coved” type.
Type 2 and Type 3, however, are essentially indistinguishable from an incomplete right bundle branch block with ST-segment elevation and a positive T-wave. These authors, based on a small case series, took 38 patients referred for ajmaline provocation testing and compared their baseline ECGs. Of the 14 patients who converted to Type 1 following ajmaline infusion, they found the baseline angle of the R’ wave differed significantly – with an alpha angle cut-off of 50 degrees and a beta angle cut-off of 58 degrees.
A little esoteric, but fascinating.
“New Electrocardiographic Criteria for Discriminating Between Brugada Types 2 and 3 Patterns and Incomplete Right Bundle Branch Block”
http://www.ncbi.nlm.nih.gov/pubmed/22093505