Quantitative assessment of harmonic power Doppler myocardial perfusion imaging with intravenous Levovist in patients with myocardial infarction: comparison with myocardial viability evaluated by thallium-201 single-photon emission computed tomography and coronary flow reserve.
BACKGROUND
Intravenous myocardial contrast echocardiography with harmonic power Doppler imaging is a novel technique for assessing myocardial perfusion.


OBJECTIVE
The aim of this study was to quantitatively assess myocardial perfusion by harmonic power Doppler imaging in patients with a previous myocardial infarction and compare myocardial contrast echocardiography results with myocardial viability evaluated by thallium-201 single-photon emission computed tomography ((201)Tl-SPECT) and the results of Doppler flow measurement of coronary flow velocity reserve.


METHODS
Twenty-three patients with anterior myocardial infarction who were scheduled for adenosine stress (201)Tl-SPECT underwent myocardial contrast echocardiography with harmonic power Doppler imaging. Harmonic power Doppler imaging was performed at rest and during adenosine infusion (0.15 mg/kg/min) using an intravenous infusion of Levovist. The peak colour pixel intensity ratios of the risk area to the control area were used for quantitative analysis of myocardial perfusion by harmonic power Doppler imaging. Coronary blood flow velocity was measured using Doppler-tipped guidewire in the distal portion of left anterior descending artery and coronary flow velocity reserve was calculated.


RESULTS
In patients with myocardial viability assessed by (201)Tl-SPECT, pixel intensity ratios both at rest and during hyperaemia were significantly higher compared with those in patients without myocardial viability (at rest: 0.62 +/- 0.28 vs 0.37 +/- 0.17, P=0.038, during hyperaemia 0.72 +/- 0.19 vs 0.40 +/- 0.18, P=0.003). Coronary flow velocity reserve was significantly different between two groups (2.35 +/- 0.43 vs 1.49 +/- 0.53, P <0.01).


CONCLUSIONS
Quantitative assessment of microvascular integrity by harmonic power Doppler imaging corresponds to the evaluation of the microcirculation by coronary flow velocity reserve.
Tani
T
T
Division of Cardiology, Kobe General Hospital, Japan.
Tanabe
K
K
Ono
M
M
Katayama
M
M
Ibuki
M
M
Mizoguchi
S
S
Takagi
T
T
Yamamuro
A
A
Tamita
K
K
Yamabe
K
K
Yagi
T
T
Nagai
K
K
Shiratori
K
K
Morioka
S
S
D000241:Adenosine; D000368:Aged; D001783:Blood Flow Velocity; D003287:Contrast Media; D017023:Coronary Angiography; D003326:Coronary Circulation; D015150:Echocardiography, Doppler; D005080:Exercise Test; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D016014:Linear Models; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011134:Polysaccharides; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon
D003287:Contrast Media; D011134:Polysaccharides; D013794:Thallium Radioisotopes; C059891:SHU 508; D000241:Adenosine