realized in has material basis at all times has occurrent part left anterior fascicular block (process) impaired anterior division of left branch of atrioventricular bundle left anterior fascicular block (disease) DOID:10272 Left bundle branch [block] or [hemiblock] disease_ontology UMLS_CUI:C0155702 DOID label changed to 'left anterior fascicular block (disease)' for symmetry reasons with 'left posterior fascicular block (disease)' SNOMEDCT_2010_1_31:4973001 SNOMEDCT_2010_1_31:266245009 SNOMEDCT_2010_1_31:195045000 ICD9CM:426.2 Left bundle branch hemiblock NOS (disorder) Left bundle branch hemiblock (disorder) left bundle branch hemiblock SNOMEDCT_2010_1_31:195044001 heart conduction disease disease course