title: Transthoracic Doppler echocardiography for the assessment of left atrial appendage size and blood flow velocity: a multicentre study.
abstract: OBJECTIVE
  The aim of this study was to evaluate the reliability of transthoracic Doppler echocardiography (TTE) in the assessment of left atrial appendage (LAA) size and function.
  
  
  METHODS
  We considered 86 consecutive patients [56 male, 30 female; mean age 64 +/- 13 years, sinus rhythm 36 patients (42%); atrial flutter/fibrillation 50 patients (58%)] referred for transoesophageal echocardiography (TEE) and TTE. Maximum LAA transverse diameters and LAA peak flow velocities were calculated by two-dimensional and pulsed-wave Doppler analysis at TEE and TTE.
  
  
  RESULTS
  LAA systolic transverse diameters were detectable in 78 patients (91%) by TTE and showed a significant correlation with TEE (r = 0.77, P < 0.0001). LAA peak flow velocities were measurable by TTE in 72 patients (84%) and were comparable with TEE (50.4 +/- 23 vs 47.3 +/- 23.2 cm/s, r = 0.67, P < 0.0001). A peak blood flow velocity of <25 cm/s at TTE was the best indicator of very low (<20 cm/s) LAA flow velocity as detected by TEE (sensitivity 93%, specificity 87%, area under the curve 0.94, P < 0.0001). Conversely, a peak blood flow velocity of >56 cm/s at TTE indicated a very high (> 40 cm/s) LAA flow velocity as detected by TEE (sensitivity 50%, specificity 96%, area under the curve 0.87; P < 0.0001).
  
  
  CONCLUSIONS
  Reliable LAA size and blood flow velocities can be obtained by TTE in consecutive, unselected patients. TTE identifies patients with low and high blood flow velocities in the LAA, providing helpful information for the definition of individual embolic risk.
authors.affiliation: Department of Cardiology, S. Spirito Hospital, Rome, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Coletta
authors.forename: Tommaso
authors.initials: T
authors.lastname: Infusino
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Sciarretta
authors.forename: Augusto
authors.initials: A
authors.lastname: Sestili
authors.forename: Paolo
authors.initials: P
authors.lastname: Trambaiolo
authors.forename: Cinzia
authors.initials: C
authors.lastname: Cianfrocca
authors.forename: Elettra
authors.initials: E
authors.lastname: De Marchis
authors.forename: Antonio
authors.initials: A
authors.lastname: Auriti
authors.forename: Alessandro
authors.initials: A
authors.lastname: Salustri
mesh_terms: D000368:Aged; D020517:Atrial Appendage / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D001783:Blood Flow Velocity; D015150:Echocardiography, Doppler; D017548:Echocardiography, Transesophageal; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity