title: Physiologic assessment of left anterior descending coronary artery stenosis by quantitative intravenous myocardial contrast echocardiography in humans: comparison with exercise single-photon emission computed tomography.
abstract: OBJECTIVE
  To clarify the potential of quantitative intravenous myocardial contrast echocardiography (MCE) for physiologic assessment of the left anterior descending artery (LAD) stenosis.
  
  
  METHODS
  We studied 38 patients with suspected coronary artery disease. MCE was performed by continuous infusion of Levovist and intermittent ultrasonic exposure. Images were obtained from the apical four-chamber view at rest and after dipyridamole infusion. The background-subtracted intensity versus pulsing interval plots were fitted to an exponential function,Y=A(1 e-ss), to obtain the plateau level (A) and rate of rise (ss) of background-subtracted intensity both at rest and after dipyridamole infusion. We compared the results with those of exercise thallium-201 single-photon emission computed tomography (SPECT).
  
  
  RESULTS
  Of the 38 patients, 18 patients exhibited redistribution in the LAD territories with SPECT (group A), although 20 did not (group B). The ss reserve (DIP/rest) in group A was significantly lower than those in group B (0.8 +/- 0.5 versus 2.0 +/- 1.1, P < 0.001), while the A reserve did not differ between the two groups (1.2 +/- 0.6 versus 1.0 +/- 0.5, P = NS). The ss reserve <1.1, which was the optimal cutoff value, provided sensitivity of 79% and specificity of 84% for the presence of redistribution in SPECT.
  
  
  CONCLUSIONS
  Quantitative intravenous MCE allows us to estimate physiologic severity of the LAD stenosis in the clinical setting.
authors.affiliation: Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, Osaka, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Fukuda
authors.forename: Takashi
authors.initials: T
authors.lastname: Muro
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hozumi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Watanabe
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamagishi
authors.forename: Minoru
authors.initials: M
authors.lastname: Yoshiyama
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Takeuchi
authors.forename: Junichi
authors.initials: J
authors.lastname: Yoshikawa
mesh_terms: D003287:Contrast Media; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D004176:Dipyridamole; D004452:Echocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D045423:Microbubbles; D008875:Middle Aged; D011134:Polysaccharides; D012680:Sensitivity and Specificity; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon; D014665:Vasodilator Agents
chemical_list: D003287:Contrast Media; D011134:Polysaccharides; D013794:Thallium Radioisotopes; D014665:Vasodilator Agents; C059891:SHU 508; D004176:Dipyridamole