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.
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.
Fukuda
Shota
S
Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, Osaka, Japan.
Muro
Takashi
T
Hozumi
Takeshi
T
Watanabe
Hiroyuki
H
Yamagishi
Hiroyuki
H
Yoshiyama
Minoru
M
Takeuchi
Kazuhide
K
Yoshikawa
Junichi
J
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
D003287:Contrast Media; D011134:Polysaccharides; D013794:Thallium Radioisotopes; D014665:Vasodilator Agents; C059891:SHU 508; D004176:Dipyridamole