INFLUENCE OF DATA-PROCESSING ON CYCLIC VARIATION OF INTEGRATED BACKSCATTER AND WALL THICKNESS IN STUNNED PORCINE MYOCARDIUM

This study was performed to investigate the relationship between the c yclic variation of integrated backscatter and myocardial wall thickeni ng in stunned myocardium. Different definitions of cyclic variation we re evaluated to be able to compare with other studies. Ultrasound data were acquired from 10 open-chested Yorkshire pigs (25-33 kg) at basel ine, during regional ischemia and during 30 min of stunning, using a b roadband ultrasound transducer (3-7 MHz) sutured directly upon the lef t ventricular myocardial wall. Cyclic variation of integrated backscat ter and myocardial wall thickening were calculated using three definit ions obtained from the literature. Independent of the definition, cycl ic variation of wall thickness and integrated backscatter were blunted during acute ischemia and returned transiently to or above baseline d uring the first minute of reperfusion, followed by a gradual decrease to a level under baseline during stunning. An early return of the cycl ic variation of the integrated backscatter was not observed in pigs, i ndependent of the data processing used. The relationship between integ rated backscatter and wall thickness was maintained. (C) 1997 World Fe deration for Ultrasound in Medicine & Biology.