Abstract TP201: Characterizing Left Atrial Mechanics and the Associations With Stroke Severity

Abstract

Introduction: The importance of left atrial (LA) function in cardioembolic stroke is increasingly recognized, but the associations between LA phasic function and ischemic stroke severity (admission NIH stroke scale (NIHSS)) is unknown. Two-dimension speckle tracking echocardiography (STE) allows an accurate, reproducible, and detailed assessment of the 3 components of the LA cycle. Methods: LA STE analysis was quantified using a post-processing wall motion tracking software according to standard definitions. Strain/strain rate curves for the 3 components of the LA cycle: 1) Reservoir (Maximum Global longitudinal strain (Smax)/strain rate (Srmax), total LA emptying fraction (tEF)) 2) Conductive (Early LA Strain rate (Sre), passive emptying fraction (pEF)) 3) Active (Late LA Strain rate (Sra), active emptying fraction (aEF)) were evaluated. The association of NIHSS (quintiles) with LA strain/strain rate was tested using ordinal logistic regression adjusted for covariates (Table 1) Results: Average participants (N=62) were middle aged, normotensive men. Incremental increases in Sre (worse LA conduction) was nonsignificantly associated with increased odds of higher NIHSS (OR 1.13 , 95%CI 0.67-1.88). Incremental increases in Sra (worse LA contraction) was associated with decreased odds of higher NIHSS that persisted after adjustment for demographics and LV function (OR 0.68, 95%CI 0.46-1.00). Better LA reservoir function (incremental Smax increases) was suggestive of decreased odds of worse stroke. Conclusions: This study suggest that odds of a more severe stroke is lower in patients with better LA reservoir function and worse LA contraction, but higher in participants with worse LA conductive function, mirroring the dynamic changes in diastolic dysfunction (impaired LA conduction, compensatory increase in contractile phase). Additional work to increase power and further characterize these associations is ongoing.