The response of regional integrated backscatter levels and regional strain to inotropic stimulation and acute ischemia

Integrated backscatter (IB) and its cyclic variation (CVIB) are echocardiographic parameters used for myocardial tissue characterization. The purpose of this study was to examine the potential mechanisms underlying the CVIB. The relationship between changes in integrated backscatter and regional myocardial strain was investigated by studying the response of both curves to inotropic stimulation and acute ischemia. Changes in integrated backscatter closely paralleled changes in wall thickening but wall thickening alone could not explain our experimental findings. The results presented in this study further support the hypothesis that changes in tissue reflectivity during the cardiac cycle are induced by regional myocardial 3D strain.