Study objectives: To evaluate the time-related change
of left atrial (LA) appendage flow velocity in chronic atrial
fibrillation (AF) by follow-up transesophageal echocardiography (TEE)
and to investigate its association with the occurrence of LA
spontaneous echo contrast.
Setting: University-based, tertiary
referral medical center.
patients with chronic nonrheumatic AF.
All studied patients underwent both a baseline and follow-up TEE during
a mean period of 13 ± 7 months.
results: Baseline TEE revealed that LA spontaneous echo contrast
was present in 28 patients (group 1) and was absent in 19 patients
(group 2). The LA appendage flow velocity profiles at baseline were
significantly lower in group 1 than in group 2; on follow-up, the
appendage flow velocities decreased significantly in group 2, but were
not significantly changed in group 1. Follow-up TEE revealed that
spontaneous echo contrast was persistent in all group 1 patients. In
group 2, LA spontaneous echo contrast was newly observed in 9 patients
(group 2A) but was persistently absent in 10 patients (group 2B). In
group 2A, all of the LA appendage flow velocity profiles decreased
significantly at the follow-up study. In group 2B, however, only LA
appendage inflow velocity integral showed significant decrease on
follow-up; there were no significant changes in LA appendage outflow
velocity indexes and peak inflow velocity.
Conclusions: LA appendage flow velocity may decrease with
time in some patients with AF, and this change is associated with a new
occurrence of LA spontaneous echo contrast. For patients without LA
spontaneous echo contrast, serial follow-up of the LA appendage flow
velocity profiles may be useful for predicting future development of
spontaneous echo contrast. Once LA spontaneous echo contrast occurs in
AF patients, it tends to persist with time and the LA appendage is
usually under a persistently low flow state.