CRITICAL REAPPRAISAL OF BEDSIDE ECHOCARDIOGRAPHIC PARAMETERS FOR ESTIMATION OF LEFT-VENTRICULAR EJECTION FRACTION IN ACUTE MYOCARDIAL-INFARCTION - IMPORTANCE OF THE WALL MOTION INDEX

The relative value of simple bedside M-mode and two-dimensional echocardiographic indices and their combinations for the estimation of the left ventricular ejection fraction (LVEF) in a single, large group of patients with acute myocardial infarction (AMI) has never been reported. Therefore, 79 patients with AMI were studied by echocardiography and radionuclide angiography within 12 h during the 2nd week following AMI. Parameters of left ventricular function by traditional M-mode indices (dimensions, fractional shortening, mitral-septal distance), by two-dimensional parameters (wall motion index, LVEF by Baran and by a truncated cone model), by statistical integration and by subjective evaluation were compared with radionuclide LVEF by linear regression. There was a clear trend towards a better accuracy by subjective evaluation of LVEF as compared with single parameter two-dimensional and M-mode methods. However, this difference of accuracy was only statistically significant with regard to M-mode dimensional parameters (R2 = 0.80 versus R2 = 0.49 to R2 = 0.24, p < 0.05). Thus, estimates of the LVEF can be obtained by multiple echocardiographic approaches which are all moderately inaccurate. The combination of parameters (wall motion index and end-systolic dimension) increased accuracy, but did not reach statistical significance. Estimates of LVEF based on a wall motion index are obtained in virtually all patients and have the additional advantage of providing data on the regional function in the same echocardiographic examination, contrary to subjective estimates of LVEF. Therefore, despite its inaccuracy, wall motion analysis appears to be the best presently known echocardiographic method for bedside estimation of LVEF in AMI.