Dobutamine echocardiography: usefulness of digital image processing

The present study was undertaken in order specifically to evaluate the usefulness of digital image processing so as to enhance the diagnostic power of dobutamine stress echocardiography. For this purpose 44 dobutamine echocardiographic tests, routinely performed in our echo laboratory, were analysed blindly by two observers using traditional videotape recording and digitized image acquisition. The results obtained from both observers show a trend which suggests that the traditional videotape approach provides more true-positive tests than the digitized approach (27/38 vs 23/38 and 24/38 vs 22/38 for the first and second observer, respectively). True-negative test detection was 6/6 with the videotape and 5/6 with the digitized method for both observers. As a consequence of the discrepancies observed between the two modalities, the videotape indicates that it can provide higher diagnostic accuracy than the digitized approach (72 +/- 9% vs 63 +/- 10%). The tests results concordance (positive or negative) between the two modalities of analysis was 66% for both the observers. The inter-observer agreement on the test results was 84% and 80% for the videotape analysis and the digitized analysis, respectively. On the basis of the results, we consider that digitized analysis applied to dobutamine stress echocardiography does not afford significant diagnostic advantages and should not be considered as an alternative option to traditional videotape analysis. However, it may be considered an extremely useful integrative tool since it produces the on-line image evaluation more easily and faster and allows a more practical form of stress test storage.