(The SANS Institute, Bethesda, MD, www.sans.org) A membership organization devoted to computer security founded in 1989.
A bundle branch block is a defect of the bundle branches or fascicles in the electrical conduction system of the heart. bundle branch block is a defect of the bundle branches or fascicles in the electrical conduction system of the heart.
Other classifications of bundle branch blocks are; 1  Bifascicular block. 2  This is a combination of right bundle branch block (RBBB) and either left anterior fascicular block (LAFB) or left posterior fascicular block (LPFB). 3  Trifascicular block.