atrial fibrillation NCI:C50466 emitraka SNOMEDCT_US_2020_03_01:266306001 UMLS_CUI:C0004238 MESH:D001281 MESH:D001281 ICD9CM:427.31 2015-01-16T14:55:21Z disease_ontology DOID:0060224 A heart conduction disease that is characterized by uncoordinated electrical activity in the heart's upper chambers (the atria), which causes the heartbeat to become fast and irregular and has symptoms palpitations, weakness, fatigue, lightheadedness, dizziness, confusion, shortness of breath and chest pain. A-fib heart conduction disease