ULTRASOUND TISSUE CHARACTERIZATION OF MYOCARDIUM IN INFANTS REFERRED FOR ECMO. † 188

Cyclic variation in integrated backscatter (CVIBS) of ultrasound has been used in adults to characterize ischemic myocardial changes at the cellular level. Neonatal normal and abnormal values in myocardial disease have recently been developed by our lab. We hypothesized that regional myocardial ischemia(decreased CVIBS) could be detected in infants referred for ECMO. ECMO and near-miss ECMO patients were enrolled prospectively, and evaluated at specified points during the hospital stay. CVIBS data (in decibels) were obtained for left ventricular posterior wall (LVPW) and interventricular septum (IVS) over 4-6 cardiac cycles, using standard echo equipment with specialized image-processing software. Standard echo measurements and physiologic data also were obtained. In ECMO and near-miss ECMO patients with similar birth weight and diagnoses, PW CVIBS was normal at admission and throughout the hospital course. In contrast, IVS CVIBS was less than normal initially in both groups, but normalized after treatment(Table). In cardiac stun (2/8 ECMO pts.), LV wall stress=55 and shortening fraction=0.18, vs. 25 and 0.38 in other ECMO infants. CVIBS was available for 1 patient. PW CVIBS remained normal(3.0), but IVS CVIBS was more markedly abnormal than for other ECMO patients(0.5;>1 SD below normal).