LEFT ATRIAL APPENDAGE BLOOD-FLOW DETERMINED BY TRANSESOPHAGEAL ECHOCARDIOGRAPHY IN PATIENTS WITH COMPLETE ATRIOVENTRICULAR-BLOCK

Function of the left atrial appendage (LAA) represented by LAA outflow is an important predictor for thrombus formation in patients with non rheumatic atrial fibrillation, but the pattern of LAA flow in patients with complete atrioventricular (AV) block has rarely been studied. Tw enty-one patients with complete AV block and an implanted WI or VVIR p acemaker were studied with transesophageal echocardiography. The LAA o utflow velocity obtained during the ventricular diastolic phase was si gnificantly higher than that obtained during the ventricular systolic phase (41.5 +/- 6.0 vs. 34.9 +/- 9.7 cm/s; p < 0.001). The LAA inflow velocity obtained during the ventricular diastolic phase was also sign ificantly higher than that obtained during the ventricular systolic ph ase (29.9 +/- 7.8 vs. 26.4 +/- 5.3 cm/s; p < 0.01). In addition, the L AA outflow and inflow velocity time integrals during the ventricular d iastolic phase were significantly higher than those during the ventric ular systolic phase (4.66 +/- 0.96 vs. 4.08 +/- 1.05 cm, p < 0.01, and 2.81 +/- 0.77 vs. 2.56 +/- 0.65 cm, p < 0.05, respectively). Thus, du e to both diastolic augmentation of the LAA flow related to active atr ial contraction and minor early diastolic LAA flow formation, left ven tricle diastolic function might have some influence on LAA flow. This may have implications for the pathogenesis of LAA thrombi in left vent ricular dysfunction.