Ultrasonic tissue characterization predicts myocardial viability in early stage of reperfused acute myocardial infarction

Abstract

Background - The aim of the present study was to characterize temporal changes in cyclic variation of ultrasonic integrated backscatter (IBS), which reflects intrinsic contractile performance, in patients with reperfused acute myocardial infarction (AMI) and to elucidate the clinical value of tissue characterization in predicting myocardial viability. Methods and Results - We recorded short-axis IBS images before and 3, 7, and 21 days after reperfusion in 26 patients with AMI and obtained the cyclic variation of lBS in the normal and infarct zones. When cyclic variation showed synchrony and asynchrony, we expressed its magnitude as positive and negative values, respectively, called the phase-corrected magnitude. We also measured average wall motion score (dyskinesis, 4; normal, 0) of the infarct segments. The phase-corrected magnitude was lower in the infarct zone than in the normal zone before reperfusion (0.3±2.5 versus 5.2±1.7 dB, P