title: [2 CASES OF ACUTE FREDERICK'S SYNDROME].
mesh_terms: D001281:Atrial Fibrillation; D002318:Cardiovascular Diseases; D006327:Heart Block; D006801:Humans; D013577:Syndrome
keywords: AURICULAR FIBRILLATION; HEART BLOCK
vernacular_title: DVA SLUCHAIA OSTRO RAZVIVSHEGOSIA SINDROMA FREDERIKA.