We used transesophageal echocardiography to study the clinical and pathologic features of smokelike echoes and left atrial
appendage (LAA) thrombi in occasions of mitral stenosis (MS), both with and without atrial fibrillation (Af), and lone atrial
fibrillation without rheumatic lesions. Forty-two patients had MS, and 77 had lone Af; mean age in the two groups was 57 years
and 66 years, respectively. In MS patients with Af, smokelike echoes were observed in 26(84%) cases, and in 11(42%) cases
with thrombi. In MS with normal sinus rhythm, smokelike echo was observed in only 1(9%) case. In the lone Af group,
smokelike echoes were observed in 18(23%) cases, and only 2(3%) cases had thrombi in LAA. None of these thrombi or
smokelike echoes were demonstrated by transthoracic echocardiography , however. The dimension and cross sectional areas in
cases of LA and LAA, blood flow velocity in cases of LAA and PV, and LVEF and LV inflow blood velocity in the groups with
and without smokelike echoes were compared. We found much larger LA volumes and LAA areas, slower blood flow velocities
in LAA and PV, lower LVEF, and slower velocities of LV inflow in the group with smokelike echoes than in the group without
these echoes. We thus conclude that stagnation of intra-atrial blood may play a major role in thrombus formation, and that
transesophageal echocardiography detected both smokelike echoes and thrombi in cases with LA and LAA with great efficacy.
Anticoagulation therapy is thus strongly recommended in cases of MS and atrial fibrillation.