Left atrial and left atrial appendage functional abnormalities in
patients with cardioembolic stroke in sinus rhythm and idiopathic atrial
fibrillation
Thrombogenesis in the left atrial appendage (LAA) has been related to
the special morphology of this cavity and to its size and degree of
dysfunction. However, no study has focused on LAA function in
conjunction with left atrial (LA) function in both sinus rhythm (SR) and
nonrheumatic idiopathic atrial fibrillation (AE) in relation to clinical
status (cardioembolic stroke). Forty-three patients in SR (14 patients
with stroke, 29 control subjects) and 45 patients in AF (27 patients
with stroke, 18 control subjects) were examined by transthoracic and
transesophageal echocardiography. Baseline clinical characteristics and
standard transthoracic and transesophageal measurements of the LA and
LAA (size, fractional area change, flow measurements, spontaneous echo
contrast, and thrombus) were recorded and compared in relation to
cardiac rhythm. Patients in the stroke-SR group showed a significant
decrease of fractional area change in the LA (32% +/- 15%) and LAA
(34% +/- 15%) in relation to control subjects (43% +/- 10%, p =
0.035, 49% +/- 13%, p = 0.006, respectively). Patients in the
stroke-AF group showed significant reduction of appendage flow
measurements (outward velocity = 22 +/- 13 vs 33 +/- 19 cm/sec, p =
0.036), whereas no differences were detected in the center of the LA. In
multiple regression analysis, the presence of cardioembolic stroke was
positively associated with the presence of spontaneous echo contrast (p
= 0.0253) and spontaneous echo contrast negatively associated with
appendage inward flow velocity (p < 0.001). Cardioembolic stroke in
patients in SR is associated with a global decrease of shortening in
both cavities and in patients with AE, with a reduction of LAA flow
parameters. Patients with spontaneous echo contrast, thrombus, or both
showed further reduction of shortening and flow velocities in both
cavities, indicating a more advanced stage of dysfunction