TRANSESOPHAGEAL ECHOCARDIOGRAPHY IN MYOCARDIAL REVASCULARIZATION .1. ACCURACY OF INTRAOPERATIVE REAL-TIME INTERPRETATION

Transesophageal echocardiography (TEE) is increasingly used intraopera tively as a monitor of ventricular function and volume. Despite ifs in creasing use, whether data from TEE monitoring can be interpreted accu rately on-line in real-time is unknown. We studied the performance of five community-based, full-time cardiac anesthesiologists during 75 su rgical procedures in which biplane TEE monitoring was used. Every 10 m in intraoperatively, each anesthesiologist evaluated the video cine lo op display of echocardiographic images to provide a real-time visual e stimate of left ventricular ejection fraction area (EFA) and left vent ricular filling at the level of the short axis and to assess regional wall-motion of the short axis and transgastric longitudinal views usin g a predefined scoring system. The same video images were analyzed qua ntitatively off-line by two blinded investigators. Intraoperative real time estimates of EFA correlated moderately with off-line quantificati on (r = 0.8, P = 0.0001). Of the 662 cine loops analyzed by both elf-l ine and real-time techniques, 386 (55%) were within +/- 5% of each oth er, 495 (75%) were within +/- 10% of each other, 561 (85%) were within +/- 15% of each other, and 617 (93%) were within +/- 20% of each othe r. The overall sensitivity and specificity of real-time echocardiograp hic ischemia detection were both 76%. However, there was individual va riation among the five anesthesiologists. Recognition of normal and se vere regional wall-motion abnormality, such as akinesis, had more conc ordance between real-time and off-line analysis, 93% and 79%, respecti vely, than recognition of mild regional wall-motion abnormalities. Ane sthesiologists can estimate EFA in real-time to within +/- 10% of off- line values in 75% of all cases. Real-time identification of normal re gional function is more accurate than identification of abnormal funct ion i.e., there is variability in quantifying the severity of regional dysfunction.