title: The feasibility of tissue Doppler acceleration as a new predictor of thrombogenesis in the left atrial appendage associated with nonvalvular atrial fibrillation.
abstract: BACKGROUND
  Tissue acceleration utilizing the tissue Doppler imaging (TDI) technique is a new marker of ventricular contraction. We evaluated whether the left atrial appendage (LAA) wall acceleration was associated with thrombosis in patients with nonvalvular atrial fibrillation (NVAF).
  
  
  METHODS
  Seven NVAF patients with thromboembolism (TE), eight without TE, and eight with normal sinus rhythm (NSR) were studied using transesophageal echocardiography. TDI was used to evaluate the LAA wall acceleration.
  
  
  RESULTS
  There was a decrease in the peak flow velocity in the TE group compared with the other two groups. There was greater LAA expansion in NVAF with TE groups (with TE [8.9 +/- 2.1 cm(2)] compared with the group without TE [7.3 +/- 2.8 cm(2)]), but the difference was not statistically significant; the difference was statistically significant compared with the NSR group (5.3 +/- 1.2 cm(2); P = 0.0035). The average of the continuous 40-frames area where tissue Doppler acceleration (TDA) was >0.024 cm/sec(2) was significantly lower in the TE group (0.12 +/- 0.05 cm(2)) compared to the group without TE (0.33 +/- 0.17 cm(2); P = 0.0017) and NSR group (0.30 +/- 0.13 cm(2); P = 0.0042), although wall velocity was not significantly different comparing the two NVAF groups. Furthermore, peak flow velocity of LAA was well correlated with LAA wall acceleration (r = 0.864, P < 0.0001).
  
  
  CONCLUSIONS
  LAA wall acceleration obtained utilizing the TDI technique may be a new predictor of thrombogenesis in patients with NVAF.
authors.affiliation: Division of Cardiovascular Medicine, Matsuyama Shimin Hospital, Matsuyama, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Takahashi
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Sumio
authors.initials: S
authors.lastname: Komatsu
authors.forename: Kengo F
authors.initials: KF
authors.lastname: Kusano
authors.forename: Tohru
authors.initials: T
authors.lastname: Ohe
mesh_terms: D000054:Acceleration; D000368:Aged; D000704:Analysis of Variance; D020517:Atrial Appendage; D001281:Atrial Fibrillation / Q000150:complications* / Q000000981:diagnostic imaging; D015150:Echocardiography, Doppler; D017548:Echocardiography, Transesophageal; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013923:Thromboembolism / Q000000981:diagnostic imaging* / Q000209:etiology*