Left atrial appendage flow velocity and spontaneous echo contrast in patients with rheumatic mitral stenosis: a multiplane transesophageal echocardiographic study.
BACKGROUND
Left atrial spontaneous echo contrast (LASEC), a putative marker of thrombo-embolic risk, is commonly located in the left atrial appendage (LAA). The aims of this work were to evaluate, using multiplane transesophageal echography, the echocardiographic determinants, specifically LAA outflow Doppler velocity, in the presence of SEC in patients with rheumatic MS.


METHODS
Transthoracic and transesophageal echocardiographic tests were performed on 61 patients. The patients were divided into 3 groups based on the presence and type of valvular disease. Patients in group I (n = 28) presented with rheumatic mitral stenosis (MS). Patients in group II (n = 18) presented with valvular heart disease other than MS, and patients in group III (n = 15) had no history of valvular heart disease. The left atrium and appendage were examined for the presence of spontaneous echocontrast and thrombus, using multiplane echo scopy with transducer rotation. Minimal and maximal appendage areas were measured, on a computer-assisted bablet, by tracing a line from the top of the limbus of the left upper pulmonary vein to the appendage endocardial border. The LAA ejection fraction was calculated according to the formula: (maximal area-minimal area)/maximal area. Mitral valvular condition was evaluated with transthoracic and transesophageal echocardiography. Left atrial appendage blood flow velocity profiles were obtained with pulsed-wave Doppler at the orifice of the LAA.


RESULTS
LASEC was present in 18 of 28 patients with mitral stenosis (64.3%). Patients with LASEC showed a greater incidence of atrial fibrillation (14/18 vs 12/43, p < 0.005), larger LAD (53.67 +/- 8.74 vs 40.54 +/- 14.85, p < 0.005), smaller LAAEF (38.7 +/- 1.53 vs 69.5 +/- 24.0, p < 0.05), smaller LAAMEV (20.28 +/- 10.07 vs 2.95 +/- 25.11, p < 0.005) and smaller LAAMFV (24.6 +/- 12.23 vs 36.00 +/- 11.01, p < 0.01), when compared with patients without LASEC. For group I, LAAEF, LAAMEV and LAAFV were smaller in patients with SEC than in patients without SEC (p < 0.005, p < 0.05, p < 0.01). However LAD values were similar for patients with and without SEC (53.67 +/- 8.75 vs 54.20 +/- 18.81, p = NS). Both LAAMEV and LAAMFV were related to SEC in patients with atrial fibrillation. However, LAD did not show the same trend.


CONCLUSIONS
LASEC is more commonly observed in patients with rheumatic mitral stenosis or atrial fibrillation. Both LAAMEV and LAAMFV are associated with SEC in these patients.
Ho
H Y
HY
Department of Internal Medicine, Taichung Veterans General Hospital, Taiwan, R.O.C.
Wang
K Y
KY
Ting
C T
CT
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016279:Atrial Function, Left; D001783:Blood Flow Velocity; D017548:Echocardiography, Transesophageal; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012214:Rheumatic Heart Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology