Abstract WP205: Left Atrial Size is Not a Predictor for Detection of Atrial Fibrillation in Cryptogenic Stroke

Objective: Left atrial dilation is considered to be an indirect marker of atrial fibrillation. The purpose of the study is to determine if an enlarged left atrium is a predictor of paroxysmal atrial fibrillation in patients with cryptogenic stroke. Methods: We performed a retrospective chart review of patients who were deemed to have cryptogenic strokes by vascular neurologists at a tertiary care center in Ohio. Patients had an implantable cardiac monitor (ICM) placed at hospital discharge and were monitored for atrial fibrillation. Age (mean: 65.8 years), Sex (male: 49.3%), initial NIHSS score (mean: 4.45), risk factors, CHADS2 score (mean: 3.54) and location were recorded. Results: 829 stroke and 295 TIA patients were screened between September 2012 and July 2016. 79 patients were deemed to have cryptogenic stroke and had an ICM placed. Left atrial size was classified based on the left atrial volume index. Of the 79 patients, 61 (77.2%) patients were found to have a normal left atrium (22 +/- 6 ml/m 2 ), 14 (17.7%) patients had mildly enlarged left atrium (29-33 ml/m 2 ), and 4 (5.06%) patients had moderately enlarged left atrium (34-39 ml/m 2 ). No patients from the cohort had severe enlargement of the left atrium (≥ 40 ml/m 2 ). 21 patients (26.6%) have been detected to have atrial fibrillation on ICM. Of the 21 patients with atrial fibrillation, 6 (28.6%) had mildly enlarged left atrium and 15 (71.4%) were found to have a normal left atrium. A higher NIHSS was found to be a predictor of atrial fibrillation (p=0.037, CI 0.83-0.99), consistent with previous studies showing that patients with atrial fibrillation have more severe strokes. Multivariate analysis failed to reveal any other significant predictors. Conclusion: Left atrial size was not a significant predictor of paroxysmal atrial fibrillation in patients with cryptogenic stroke. A normal atrial size should not preclude placement of an ICM for detection of paroxysmal atrial fibrillation.