The relationship between clinical variables (qualifying history duration of AF, AF duration, CHADS2VASC score, biomarkers, conversion to sinus rhythm, left atrial function and left atrial volume), confounding variables and incidence of new silent cerebral ischemic lesions at Day 1 and 7-10 post MR will be tested in a multiple logistic regression model, using a stepwise selection procedure (p<0.05). The model will be validated using bootstrapping.