Effect of pre-reperfusion residual flow on recovery from myocardial stunning: a myocardial contrast echocardiography study.
BACKGROUND
Myocardial contrast echocardiography (MCE) may be used to assess coronary microvasculature in patients with myocardial infarction. Myocardial contrast echocardiography-no reflow suggests poor functional outcome; however, MCE with reflow does not necessarily indicate good myocardial salvage or sufficient functional recovery from myocardial stunning. In this study, MCE was performed to assess the effect of pre-reperfusion residual flow (PRF) on the recovery from myocardial stunning.


RESULTS
The size of the occluded bed, an area supplied with an infarct-related artery, was determined by comparing pre- and post-reperfusion MCE images in 40 patients with first acute myocardial infarction. Myocardial contrast echocardiography-no reflow was observed after reperfusion in 8 patients. Significant PRF was not recognizable in any of the 8 patients. The other patients with MCE reflow were subdivided into 2 groups on the basis of the ratio of the area perfused by PRF to that of the occluded bed: 14 patients with the ratio of more than 10% (PRF[+]), and the other 18 patients (PRF[-]). The wall motion score (0, normal to 4, dyskinetic) was obtained in the convalescent stage.


RESULTS
(1) Wall motion of the infarct area after day 3 was better in patients with PRF than in patients without PRF. (2) Left ventricular functional improvement in the long term was remarkable in patients with good reflow and PRF(+), modest in patients with good reflow but PRF(-), and not detectable in patients with MCE-no reflow. No significant correlation was found between angiographic collateral grades and PRF.


CONCLUSIONS
The presence of residual flow within the infarct area before reperfusion results in not only good myocardial salvage but also rapid functional recovery from myocardial stunning.
Lim
Y J
YJ
Department of Cardiology, Kawachi General Hospital, Osaka, Japan.
Masuyama
T
T
Mishima
M
M
Fukui
O
O
Nakatani
D
D
Kawano
S
S
Sakata
Y
Y
Kodama
K
K
Hori
M
M
D003326:Coronary Circulation / Q000502:physiology*; D004452:Echocardiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015425:Myocardial Reperfusion; D017682:Myocardial Stunning / Q000000981:diagnostic imaging* / Q000503:physiopathology*