AUTOMATED ECHOCARDIOGRAPHIC ANALYSIS - EXAMINATION OF SERIAL INTRAOPERATIVE MEASUREMENTS

Background: Although transesophageal echocardiography allows continuou s intraoperative cardiac monitoring, the technique has been limited by the lack of a method for realtime, quantitative assessment of cardiac chamber size and systolic function. Automated border detection (ABD), based on an analysis of integrated backscatter, is a new technique th at is purported to provide real-time, quantitative assessment of left ventricular (LV) areas and fractional area change (FAG). A prospective investigation was designed to assess the accuracy and trending capabi lity of ABD during continuous intraoperative monitoring. Methods: In 1 6 patients monitored throughout noncardiac surgical procedures, serial real-time estimates of LV end-diastolic area (EDA), end-systolic area (ESA), and FAC by ABD were compared with paired off-line manual measu rements made by two experienced echocardiographers. Results: There was a high correlation between real-time ABD estimates of LV ESA (r = 0.9 3), EDA (r = 0.89), and FAC (r = 0.90) to those of the off-line techni que. The automated technique systematically underestimated both EDA an d ESA, resulting in a small underestimation of FAG. The automated tech nique demonstrated an accuracy rate of 96% in tracking serial changes in LV area, The technique performed with an 83% sensitivity and 85% sp ecificity for detecting acute changes in LV area, Conclusions: This an alysis of serial intraoperative echocardiograms demonstrates the accur acy of ABD to estimate LV area in real time and to track serial change s in cardiac area during surgery. Although ABD is an automated techniq ue, application by personnel experienced in its operation and an echoc ardiographic system that includes lateral-gain adjustment controls are recommended for its optimal performance.