COMPARISON BETWEEN RADIONUCLIDE EJECTION FRACTION AND FRACTIONAL AREACHANGES DERIVED FROM TRANSESOPHAGEAL ECHOCARDIOGRAPHY USING AUTOMATEDBORDER DETECTION

Background: Left ventricular fractional area changes (FAC) can be deri ved from transesophageal echocardiography using an automated border de tection system. However, FAC has not yet been compared to left ventric ular ejection fraction (EF) evaluated by a reference technique. The ai m of this study was to correlate transesophageal echocardiography auto mated FAC to EF derived from radionuclide angiography to obtain a quan tifying method of global left ventricular systolic function at the bed side. Methods: Ten critically ill patients, whose lungs were mechanica lly ventilated, were included in this prospective study. Patients were scheduled for radionuclide EF evaluation when at least 75% of the end ocardium was clearly visualized on transesophageal echocardiography. P atients with esophageal pathology or cardiac dysrhythmia were excluded . Ejection fraction derived from radionuclide angiography was measured using technetium 99m. Echocardiographic data were obtained using an u ltrasound system with automated border capabilities. Simultaneous meas urements of left ventricular EF and FAC were obtained for each patient , both before and after starting a dobutamine intravenous infusion to modify left ventricular contractility. Results: Mean values for radion uclide EF and transesophageal echocardiography FAC were, respectively: 55% +/- 19% (range 19-89%) and 46% +/- 18% (range 17-80%). Left ventr icular EF and FAC were significantly correlated (r = 0.85, SEE = 9.6%) . variations of EF and FAC, induced by dobutamine, were also correlate d (r = 0.70, SEE = 4.9%). Conclusions Fractional area changes determin ed by transesophageal echocardiography using automated border detectio n correlate web with radionuclide EF and may be used at the bedside to quantify left ventricular function in selected intensive care unit pa tients.