SENSITIVITY AND SPECIFICITY OF LEFT-VENTRICULAR EJECTION FRACTION BY ECHOCARDIOGRAPHIC AUTOMATED BORDER DETECTION - COMPARISON WITH RADIONUCLIDE VENTRICULOGRAPHY

Background: Echocardiographic automated border detection (ABD) provide s on-line, beat-to-beat estimation of left ventricular (LV) ejection f raction (EF). Sensitivity and specificity of using ABD-EF for diagnosi ng LV dysfunction in routine clinical situations have not been previou sly studied. Hypothesis: Analysis of ABD-EF data based on receiver ope rating characteristic (ROC) should provide useful information about se nsitivity and specificity for clinical diagnosis of LV function based on ABD-EF. Methods: The study group included 50 consecutive patients w ith EF measured by both ABD and radionuclide ventriculography (RVG). A BD-EF was recorded for 25 consecutive heart beats in the apical four-c hamber view. Data were analyzed statistically by linear regression, Bl and-Altman plot, and ROC. In ROC analysis, abnormal LV function was de fined RVG-EF less than or equal to 40%. Results: ABD and RVG showed a moderate correlation in the EF measurements: slope = 0.93, intercept = 17%, r = 0.79 (n = 50). Interbeat variability in ABD was diminished b y averaging consecutive beats; standard error of estimate (SEE) decrea sed from 15.6% without averaging to 12.5% with 25-beat averaging. Blan d-Altman analysis indicated that ABD-EF compared unfavorably with RVG- EF, with limits of agreement from -11% to 39%. ABD-EF showed a systema tic overestimation (p < 0.005), which was compensated by increasing th e threshold for abnormal ABD-EF to 56%. With the optimized threshold, ABD-EF provided 89% sensitivity and 89% specificity (85% overall diagn ostic accuracy) for diagnosing abnormal LV function. Conclusion: This study explored the limitations of on-line echocardiographic measuremen t of EF in a clinical setting and provided useful data for assessing i nterbeat variability, sensitivity, and specificity.