Left Ventricular Abnormality and Covert Atrial Fibrillation in Embolic Stroke of Undetermined Source.

Aims The relationship between left ventricular (LV) function and AF detection in embolic stroke of undetermined source (ESUS) patients with insertable cardiac monitors (ICMs) remains unclear. We investigated the association between LV function and AF detection in patients with ESUS after ICMs implantation. Methods We enrolled patients with ESUS who underwent ICMs implantation from September 2016 to September 2020 using a single-center, prospective registry. LV systolic and diastolic functions were assessed on precordial echocardiography by LV fractional shortening (LVFS) and average E/e', respectively. Associations between characteristics of LV function and detection of AF by ICMs were analyzed. Results Participants comprised 101 patients (median age, 74 years; male, 62%). During a median follow-up period of 442 days (interquartile range (IQR), 202-770 days), AF was detected in 24 patients (24%). Median duration from ICMs implantation to AF detection was 71 days (IQR, 13-150 days). When LVFS and E/e' were dichotomized by cutoff value, each of low LVFS (＜35.5%; adjusted hazard ratio (HR), 4.77; 95% confidence interval (CI), 1.77-12.9) and high E/e' (≥ 8.65; adjusted HR, 4.56; 95%CI, 1.17-17.7) were independently associated with AF detection after adjusting for age and sex. When patients were divided into four groups according to dichotomized LVFS and E/e', the combination of low LVFS and high E/e' was independently associated with AF. Conclusions In patients with ESUS after ICMs implantation, the LV characteristics of low LVFS and high E/e' were associated with AF detection.