CLINICAL IMPLICATIONS OF LEFT ATRIAL APPENDAGE FUNCTION - ITS INFLUENCE ON THROMBUS FORMATION

This study evaluated the relation between left atrial appendage (LAA) function and LAA spontaneous echo contrast (SEC) or thrombus formation . Seventy-five patients (45 men and 30 women, aged 14-79 years) referr ed for transesophageal echocardiography (TEE) were examined for LAA ar ea (maximal and minimal), LAA ejection fraction ([LAA maximal area - L AA minimal area]/LAA maximal area), LAA peak emptying velocity, and th ese patients were classified into three groups by different LAA blood flow patterns: Group 1 - 25 patients with well-defined biphasic config uration of LAA flow; Group 2 - 28 patients with multiphasic configurat ion of LAA flow; Group 3 - 22 patients with very low LAA blood flow an d, sometimes, barely detected Doppler signal. All the 25 patients in G roup 1 had a sinus rhythm during TEE study, while the other 50 patient s in Groups 2 and 3 were in atrial fibrillation. The patients in Group 3 had the lowest LAA ejection fraction and the lowest peak emptying v elocity of these three groups. LAA SEC was present in five of 28 patie nts in Group 2 and 14 of 22 patients in Group 3, but in none of 25 pat ients in Group 1 (P < 0.001). LAA thrombus was present in one of 25 pa tients in Group 1, two of 28 patients in Group 2, and seven of 22 pati ents in Group 3 (P < 0.05). In conclusion, this study found that patie nts with poor LAA function, which was represented by lower LAA ejectio n fraction and lower peak emptying velocity, had higher incidence of L AA SEC or thrombus formation.