REPRODUCIBILITY OF DIGITAL EXERCISE ECHOCARDIOGRAPHY

We determined the intra, inter-observer and temporal variability of up right bicycle exercise echocardiography in 50 consecutive patients wit h suspected coronary heart disease. Using significant artery stenoses as reference, the sensitivity of digital exercise echocardiography was 89% and the specificity 92%. Regarding the presence or absence of exe rcise-induced ischaemia, intra-observer agreement was 86% (73-94% with 95% confidence limits, kappa value (K) 0.70 (0.50-0.91)). Inter-obser ver agreement between two independent observers was 92 (81-98)% (K=0.8 1 (0.63-0.99)). Temporal variability, was examined by repeating exerci se echocardiography after one week in 30 stable patients; it demonstra ted 90 (78-97)% agreement (K=0.71 (0.40-1.00)). The inter-observer agr eement appeared to be lower in patients or myocardial segments with wa ll motion abnormalities at vest (86% and 82%, respectively) than in pa tients or segments with normal myocardial function at rest (96% and 94 %, respectively); ns, P<0.05, respectively). Analysis of specific regi ons showed a significantly higher level of agreement (P<0.05) regardin g exercise-induced ischaemia in segments supposed to be supplied by th e circumflex branch of the left coronary artery (96%) than in the perf usion bed of the left anterior descending branch (87%) and right coron ary artery (88%). Comparing estimated values of echocardiographic ejec tion fraction, analysis of intra-observer variability showed a correla tion coefficient of 0.91 and 95% confidence limits of a single estimat e of ejection fraction of +/- 10.3%. Col responding analyses of inter- observer and temporal variability showed correlation coefficients of 0 .93 and 0.84, respectively, and 95% confidence limits of single estima tes of ejection fraction of +/- 9.6% and +/- 13.0%, respectively. Thus , the diagnostic result and the reproducibility of digital exercise ec hocardiography are satisfactory and comparable with those obtained by myocardial scintigraphy. However, approximately 10% of the examination results may be reversed when the test is repeated ol reevaluated by t he same or by another observer. The result seems to be less reproducib le in patients with abnormal wall motion at rest than in patients with normal myocardial function before exercise.