Abstract
MicroRNAs (miRNA) are prerequisite for cardiovascular functions. miRNA miR-208 b is a cardio-specific miRNA with tissue (atrial) levels elevated in atrial fibrillation (AFib) and blood levels significantly elevated in myocardial infarction. We calculated serum levels of miR-208 b in paroxysmal and persistent AFib, embolic cerebrovascular accident patients with AFib as possible etiology and controls. There was a statistically significant change of miR-208 b levels in paroxysmal (p = 0.044) and persistent (p = 0.040) AFib patients, but not for embolic CVA patients. miR-208 b could serve as a new serum marker for paroxysmal AFib.