title: Detection of coronary stenoses at rest with myocardial contrast echocardiography.
abstract: BACKGROUND
  We hypothesized that autoregulatory changes in arteriolar blood volume (aBV) that develop distal to a stenosis can be measured with myocardial contrast echocardiography, allowing coronary stenosis detection at rest without recourse to stress.
  
  
  RESULTS
  Patients with varying degrees of coronary artery stenosis on quantitative angiography underwent high-mechanical-index myocardial contrast echocardiography at 15 Hz to allow measurement of phasic changes in aBV in large intramyocardial vessels using either Definity (group 1; n=22) or Imagent (group 2; n=22). Progressive increases in the
  
  
  BACKGROUND
  <0.001) and group 2 (0.10+/-0.05, 0.27+/-0.18, 0.39+/-0.28, and 0.74+/-0.37; P<0.0001) patients. A systolic/diastolic aBV signal ratio of >0.34 provided a sensitivity and specificity of 80% and 71%, respectively, for the detection of >75% coronary stenosis in group 1 patients, whereas a ratio of >0.43 provided a sensitivity and specificity of 89% and 74%, respectively, for the detection of >75% stenosis in group 2 patients.
  
  
  CONCLUSIONS
  Both the presence and severity of a physiologically significant coronary stenosis can be detected at rest by measuring the increase in aBV on myocardial contrast echocardiography that occurs distally to the stenosis without recourse to any form of stress.
authors.affiliation: Cardiovascular Imaging Center, Cardiovascular Division, Department of Medicine, University of Virginia, Charlottesville, VA, USA. weik@OHSU.edu
authors.forename: Kevin
authors.initials: K
authors.lastname: Wei
authors.forename: Khim Leng
authors.initials: KL
authors.lastname: Tong
authors.forename: Todd
authors.initials: T
authors.lastname: Belcik
authors.forename: Patrick
authors.initials: P
authors.lastname: Rafter
authors.forename: Michael
authors.initials: M
authors.lastname: Ragosta
authors.forename: Xin-Qun
authors.initials: XQ
authors.lastname: Wang
authors.forename: Sanjiv
authors.initials: S
authors.lastname: Kaul
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003326:Coronary Circulation; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003971:Diastole; D004452:Echocardiography / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D015588:Observer Variation; D012146:Rest; D012680:Sensitivity and Specificity; D013599:Systole
chemical_list: D003287:Contrast Media