CLINICAL IMPLICATIONS OF LEFT ATRIAL APPENDAGE FLOW PATTERNS IN NONRHEUMATIC ATRIAL-FIBRILLATION

Left atrial appendage (LAA) function and flow patterns in 29 patients with chronic nonrheumatic atrial fibrillation mere studied by transeso phageal echocardiography. These 29 patients (16 men and 13 women; mean age, 63.8 years; range, 38 to 77 years) were classified into two grou ps according to different LAA flow patterns. Seventeen patients (group 1) had well-defined LAA emptying and filling Doppler flow signals, an d the other 12 patients (group 2) had very low LAA flow signals. No si gnificant differences mere found in age, sex, mean duration of atrial fibrillation, left ventricular end diastolic dimension, and left ventr icular ejection fraction between the two groups. However, group 2 pati ents had larger left atrial diameter (42.8 +/- 4.2 mm vs 36.6 +/- 8.8 mm; p < 0.05), lower LAA ejection fraction (26.4 +/- 15.2 percent vs 4 2.6 +/- 14.1 percent; p < 0.05), and lower LAA peak emptying velocity (0.13 +/- 0.03 m/s vs 0.36 +/- 0.16 m/s; p < 0.001). Higher incidence of LAA spontaneous echocardiographic contrast formation in group 2 pat ients (8/12 vs 1/17; p < 0.001) was noted. In conclusion, a subset of patients with nonrheumatic atrial fibrillation were found to have lowe r LAA blood flow and poorer LAA function. These patients had higher in cidence of left atrial or LAA spontaneous echo contrast formation whic h had been proved previously to be a marker for future systemic thromb oembolism.