Brugada syndrome:
- is listed here because it can mimic or be associated with RBBB
- Brugada syndrome is caused by a sodium or calcium channel mutation and is a cause of sudden onset ventricular tachycardia or ventricular fibrillation in children and adults
- the diagnostic criteria for Brugada syndrome is
- J point elevation with ST elevation in V1-V3
- the ST is described as coved or saddlebacked:
- coved = downsloping and convex upward
- saddlebacked = flat ST elevation with initial and final parts of ST segment slightly higher
- the ST is abnormal because the abnormal ion channels result in electrical currents during the ST segment (during which in a normal heart, there is typically little to no current movement)
There are 3 types of Brugada syndrome. Type 1 has the "coved" ST and types 2 and 3 have the saddleback morphology:
Coved ST Saddleback ST
- Brugada syndrome does not cause a wide QRS nor an R' wave. However, the ST elevation can be misinterpretted as an R' wave. When this happens, the QRS would erroneously be seen as wide.
- remember that the ST segment in RBBB should be isoelectric and flat (blue circle). In these 2 examples, it is actually slightly depressed in fact:
