Quantitative assessment of harmonic power doppler myocardial perfusion imaging with intravenous Levovist in patients with myocardial infarction: comparison with myocardial viability evaluated by coronary flow reserve and coronary flow pattern of infarct-related artery.
BACKGROUND
Myocardial contrast echocardiography and coronary flow velocity pattern with a rapid diastolic deceleration time after percutaneous coronary intervention has been reported to be useful in assessing microvascular damage in patients with acute myocardial infarction.


OBJECTIVE
To evaluate myocardial contrast echocardiography with harmonic power Doppler imaging, coronary flow velocity reserve and coronary artery flow pattern in predicting functional recovery by using transthoracic echocardiography.


METHODS
Thirty patients with anterior acute myocardial infarction underwent myocardial contrast echocardiography at rest and during hyperemia and were quantitatively analyzed by the peak color pixel intensity ratio of the risk area to the control area (PIR). Coronary flow pattern was measured using transthoracic echocardiography in the distal portion of left anterior descending artery within 24 hours after recanalization and we assessed deceleration time of diastolic flow velocity. Coronary flow velocity reserve was calculated two weeks after acute myocardial infarction. Left ventricular end-diastolic volumes and ejection fraction by angiography were computed.


RESULTS
Pts were divided into 2 groups according to the deceleration time of coronary artery flow pattern (Group A; 20 pts with deceleration time > or = 600 msec, Group B; 10 pts with deceleration time < 600 msec). In acute phase, there were no significant differences in left ventricular end-diastolic volume and ejection fraction (Left ventricular end-diastolic volume 112 +/- 33 vs. 146 +/- 38 ml, ejection fraction 50 +/- 7 vs. 45 +/- 9 %; group A vs. B). However, left ventricular end-diastolic volume in Group B was significantly larger than that in Group A (192 +/- 39 vs. 114 +/- 30 ml, p < 0.01), and ejection fraction in Group B was significantly lower than that in Group A (39 +/- 9 vs. 52 +/- 7%, p < 0.01) at 6 months. PIR and coronary flow velocity reserve of Group A were higher than Group B (PIR, at rest: 0.668 +/- 0.178 vs. 0.248 +/- 0.015, p < 0.0001: during hyperemia 0.725 +/- 0.194 vs. 0.295 +/- 0.107, p < 0.0001; coronary flow velocity reserve, 2.60 +/- 0.80 vs. 1.31 +/- 0.29, p = 0.0002, respectively).


CONCLUSIONS
The preserved microvasculature detecting by myocardial contrast echocardiography and coronary flow velocity reserve is related to functional recovery after acute myocardial infarction.
Tani
Tomoko
T
Division of Cardiology, Kobe General Hospital, 4-6 Minatojima-Nakamachi, Kobe, Japan. tomokot@kcgh.gr.jp
Tanabe
Kazuaki
K
Tani
Minako
M
Ono
Fumie
F
Katayama
Minako
M
Tamita
Koichi
K
Kaji
Shuichiro
S
Yamamuro
Atsushi
A
Nagai
Kunihiko
K
Shiratori
Kenichi
K
Morioka
Shigefumi
S
Kihara
Yasuki
Y
D001783:Blood Flow Velocity; D003287:Contrast Media; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D004452:Echocardiography; D018618:Echocardiography, Doppler, Color; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000000981:diagnostic imaging*; D011134:Polysaccharides; D012720:Severity of Illness Index; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology
D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508