title: New noninvasive method for coronary flow reserve assessment: contrast-enhanced transthoracic second harmonic echo Doppler.
abstract: BACKGROUND
  We tested the hypothesis that blood flow velocity could be recorded in the left anterior descending coronary artery (LAD) during transthoracic echocardiography by use of second harmonic echo Doppler modality along with contrast enhancement (intravenous Levovist) at rest and after pharmacologically induced maximal vasodilation to assess coronary flow reserve (CFR) with a totally noninvasive approach.
  
  
  RESULTS
  Fifty-six consecutive patients undergoing coronary angiography underwent transthoracic contrast-enhanced pulsed-wave Doppler recording of blood flow velocity in the LAD by use of harmonic color Doppler as a guide at rest and after maximal vasodilation by dipyridamole infusion. Contrast enhancement with the harmonic mode greatly improved the success rate of recording adequate pulsed-wave Doppler signal in the LAD. CFR was (mean+/-SD) 1.54+/-0.7 in patients with (group 1) and 2. 79+/-0.9 in patients without (group 2) significant LAD stenosis (lumen narrowing >70%) (P<0.001); sensitivity and specificity in detecting significant LAD stenosis were 86% and 90%, respectively. There was close agreement between CFRs determined by this new method and intracoronary Doppler flow wire.
  
  
  CONCLUSIONS
  Contrast-enhanced transthoracic echo Doppler with the harmonic mode is a feasible and promising technique for assessing CFR in a totally noninvasive way.
authors.affiliation: Institute of Cardiology, University of Cagliari, Cagliari, Italy. carlo.caiati@teseo.it
authors.forename: C
authors.initials: C
authors.lastname: Caiati
authors.forename: C
authors.initials: C
authors.lastname: Montaldo
authors.forename: N
authors.initials: N
authors.lastname: Zedda
authors.forename: A
authors.initials: A
authors.lastname: Bina
authors.forename: S
authors.initials: S
authors.lastname: Iliceto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods; D003326:Coronary Circulation; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D004176:Dipyridamole; D018618:Echocardiography, Doppler, Color / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D006940:Hyperemia / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012680:Sensitivity and Specificity; D014665:Vasodilator Agents