Abstract 3065: Mean Left Atrial Free wall and Mitral Lateral Annulus Deformation, Mid Left Atrial Free wall Velocity are Novel Independent Indicators of Clot Formation in Atrial Fibrillation- Combined Results of Observational and Validative Studies.
Background: We investigated the potential role of tissue Doppler to indicate the presence of a clot in the left atrium (LA) or embolic events in patients with atrial fibrillation (AF).
Methods: We did an initial observational study for 2 years in 76 patients with rheumatic mitral valve disease in chronic AF who had not received anticoagulation, with (Group 1, n=24) and without (Group 2, n=52) thromboembolism. The results were tested in a prospective validative study for 18 months in 42 AF (10 non-valvular AF) patients who were not on anticoagulation before admission, 12 of whom had a LA clot or embolic events. Pulsed Doppler systolic (S1, S2) tissue velocities, velocity time integrals (VTI) from 25 locations in atria and ventricles (average of 5 beats), mean LA and free-wall VTI were calculated. Transesophageal echocardiography and D-dimer levels were done.
Results: Out of the 5 highly significant parameters obtained in the logistic regression analysis, Pearson’s correlation test (n=118) showed mean LA free wall VTI, mitral lateral annulus VTI and mid-LA free wall S2 velocity were relatively independent (r<0.4, for all) of each other and were associated with clot formation. These 3 parameters were independent of heart rate, ejection fraction and LA size (R2<0.2, for each).
Conclusion: Tissue Doppler derived parameters may be used to indicate clot formation in patients with atrial fibrillation.