Clinical studies of myocardial integrated backscatter in old myocardial infarction patients during dobutamine stress / 中华超声影像学杂志

ABSTRACT

ObjectiveTo discuss the myocardial integrated backscatter (IB) characterization in old myocardial infarction (OMI) patients during the low dose dobutamine stress echocardiography (DSE). Methods Twenty eight OMI patients underwent 4 stages low dose DSE (0, 5, 10 and 20 ?g?kg -1 ?min -1 dobutamine infusion).The cardiac variation of IB (CVIB) and calibrated CVIB (CVIB%) were measured according to different segments (anterior septum, anterior wall, inferior wall and post wall of left ventricle) in different stages.ResultsIn the viable segments (Group C), CVIB and CVIB% increased from low level in early stage (5～10 ?g?kg -1 ?min -1 ) then maintaining in high level to the endpoint (20 ?g?kg -1 ?min -1 ), while maintained high level in control segments (Group A). Both CVIB and CVIB% were lower in non viable segments(Group D) than in Group A without changing during all stages. ConclusionsThe indexes of IB under dobutamine infusion were valuable for the quantitative evaluating the contractility of myocardium in OMI patients, especially for the viable myocardium.