Syncope and Conduction Risks.

Bifascicular block entails conduction delay or "block" below the atrioventricular node in two of three fascicles: the right bundle branch, and the left anterior and posterior fascicles of the left bundle branch. Typically, right bundle branch block (RBBB) coexists with either left anterior fascicular block (LAFB) or left posterior fascicular block (LPFB), with potential progression to complete heart block. [ABSTRACT FROM AUTHOR]