Bifascicular block is a conduction abnormality in the heart where two of the three main fascicles of the His/Purkinje system are blocked. Most commonly, it refers to a combination of right bundle branch block (RBBB) and either left anterior fascicular block (LAFB) or left posterior fascicular block (LPFB). Some authors consider left bundle branch block (LBBB) to be a technical bifascicular block, since the block occurs above the bifurcation of the left anterior and left posterior fascicles of the left bundle branch. The heart and lungs, from an older edition of Grays Anatomy. ... The word fascicle derives from the Latin fascis (bundle). Fascicles are the sections of a book, usually a reference work, that because of its length, is issued in parts so that the information may be made available to the public as soon as possible rather than waiting years or decades... The normal electrical conduction in the heart allows the impulse that is generated by the sinoatrial node (SA node) of the heart to be propagated to (and stimulate) the myocardium (Cardiac muscle). ... Right bundle branch block (RBBB) is a cardiac conduction abnormality seen on electrocardiogram (EKG). ... ECG characteristics of a typical LBBB showing wide QRS complexes with abnormal morphology in leads V1 and V6. ... The noun bifurcation (from latin bifurcare, to split (fork) into two), has several related meanings. ...