Recovery of stunned myocardium in acute myocardial infarction quantified by strain rate imaging: a clinical study.
BACKGROUND
Strain rate (SR) imaging (SRI) is a tissue Doppler-based method of regional myocardial deformation imaging. The aim of this study was to see whether SRI could quantify changes in myocardial mechanical function after an acute myocardial infarction, and to follow the time course of these changes.


METHODS
In all, 26 consecutive patients with first-time acute myocardial infarctions were examined on days 1, 7, and 90. Segments were analyzed with SRI and wall-motion score.


RESULTS
Peak systolic SR in infarcted segments increased significantly in magnitude from day 1 to 7 (-0.45 to -0.68 s -1 , P < .001), but not after day 7. The deformation rate in border zone segments also increased significantly from day 1 to 7 (-0.8 to -0.95 s -1 , P < .05), with no further significant changes at 3 months. In normal segments, peak systolic SR decreased in magnitude during the first week. Systolic strain showed similar results as peak systolic SR.


CONCLUSIONS
SRI can demonstrate small changes in deformation rate from midinfarct through the infarct and border zone to normal myocardium. It can also show changes over time, probably as a result of recovery of stunned myocardium.
Ingul
Charlotte Bjork
CB
Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway. charlotte.b.ingul@medisin.ntnu.no
Stoylen
Asbjorn
A
Slordahl
Stig A
SA
D000368:Aged; D000369:Aged, 80 and over; D015150:Echocardiography, Doppler; D018619:Echocardiography, Doppler, Pulsed; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017682:Myocardial Stunning / Q000000981:diagnostic imaging*