Detection of coronary stenoses at rest with myocardial contrast echocardiography.
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.
Wei
Kevin
K
Cardiovascular Imaging Center, Cardiovascular Division, Department of Medicine, University of Virginia, Charlottesville, VA, USA. weik@OHSU.edu
Tong
Khim Leng
KL
Belcik
Todd
T
Rafter
Patrick
P
Ragosta
Michael
M
Wang
Xin-Qun
XQ
Kaul
Sanjiv
S
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
D003287:Contrast Media