Abstract WP153: Relative Risk of Atrial Fibrillation Detection with Prolonged External Cardiac Monitoring and MRI Infarct Patterns.

Background and Aim: Current guidelines recommend prolonged rhythm monitoring for up to 30 days in patients with cryptogenic stroke/embolic stroke of undetermined source (ESUS). The role of monitoring in patients with lacunar infarcts, is unknown. We conducted a multicenter retrospective cohort study aimed at determining the atrial fibrillation (AF) detection yield in patients with MRI defined infarct patterns. Methods: An ECM database was used to identify patients from stroke units across a single state. Patients were included if an MRI with Diffusion-Weighted Imaging (DWI) sequences was obtained and ECM was initiated within 30 days of stroke. Image analysis included DWI lesion diameter, planimetric volume measurement and Fazekas scale scoring. Infarcts were classified as embolic/lacunar (isolated subcortical DWI lesions, diameter