Abstract
Background: Atrial cardiopathy is a proposed mechanism of
embolic stroke of undetermined source (ESUS). Left atrial (LA) strain
may identify early atrial cardiopathy prior to structural changes. We
aim to study the associations between LA strain, ESUS, and atrial
fibrillation (AF) detection in ESUS.
Methods: The study population included patients with ESUS and
non-cardioembolic (NCE) stroke presenting to statewide stroke center
between January 2016 and June 2017 who underwent transthoracic
echocardiography. Speckle tracking echocardiography (STE) was used to
measure the 3 phases of LA strain (reservoir, conduit, and contractile).
Binary logistic regression analysis was performed to determine the
associations between LA strain and stroke subtype (ESUS vs. NCE) as well
as follow-up detection of AF in ESUS patients.
Results: We identified 656 patients, 307 with ESUS and 349 with
NCE. In binary logistic regression, the lowest tertiles of LA reservoir
(adjusted OR 1.944, 95% CI 1.266-2.986, p = 0.002), contractile (aOR
1.568, 95% CI 1.035-2.374, p = 0.034), and conduit strain (aOR 2.288,
95% CI 1.448-3.613, p = 0.001) were more likely to be significantly
associated with ESUS compared to NCE stroke. Among all ESUS patients,
the lowest tertiles of LA reservoir strain (OR 2.534, 95% CI
1.029-6.236, p = 0.043), contractile strain (OR 2.828, 95% CI
1.158-6.903, p = 0.022), and conduit strain (OR 2.614, 95% CI
1.003-6.815, p = 0.049) were significantly associated with subsequent
detection of AF.
Conclusion: Reduced LA strain is associated with ESUS
occurrence and AF detection in ESUS patients. Therefore, quantification
of LA strain in ESUS patients may improve risk stratification and guide
secondary prevention strategies.
Key words: Left Atrial Strain; Atrial Cardiopathy; ESUS; Atrial
Fibrillation;