Echocardiographic Parameters
2D TTE was performed either during the index hospitalization or within
three months of the indexed ischemic stroke. Studies were performed
according to the guidelines from the American Society of
Echocardiography (ASE)22, and reports were generated
by cardiologists board-certified in echocardiography. Phasic LA function
was quantified off-line using TOMTEC (Chicago, IL)23according to guidelines from the European Association of Cardiovascular
Imaging (EACVI)/ASE Task Force24. The procedure
entailed a careful selection of TTE images capturing optimal views of
the left atrium (LA). Specifically, the LA-focused apical 4-chamber
(A4-C) and 2-chamber (A2-C) views providing the clearest visualization
were obtained. In cases where the A4-C view did not provide sufficient
clarity, the A2-C view was used independently. After thorough assessment
of multiple cardiac cycles, a single cardiac cycle presenting the best
image quality was chosen. The LA endocardial border was manually traced
from mitral annulus at one side, extrapolating across the pulmonary
veins and atrial appendage orifices to the opposite side in the
end-diastolic and end-systolic phases of a cardiac cycle (Figure 2).
This generated average atrial strain curve with two peaks. LA reservoir
strain was calculated by measuring the peak atrial longitudinal strain
(PALS) at the end of ventricular systole, corresponding with the first
peak. LA contractile strain was calculated by measuring the peak atrial
contraction strain (PACS) at the onset of atrial contraction,
corresponding with the second peak. Conduit (passive emptying) strain
was calculated by the difference between the PALS and
PACS12, 24 (Figure 2). The quality of wall tracking
was recorded according to the number of walls appropriately tracked.
Echocardiography analysis was blinded to stroke subtype and outcomes.