Copyright © 1993 by the European Society of Cardiology.
© 1993 The European Society of Cardiology
Inter- and intra-observer variability in detection of patent foramen ovale with contrast echocardiography
*Department of Cardiology, Aberdeen Royal Infirmary Foresterhill, Aberdeen AB9 2ZD,Scotland,U.K.
Hyperbaric Medicine Unit, Aberdeen Royal Infirmary Foresterhill, Aberdeen AB9 2ZD,Scotland,U.K.
Received 3 August 1992; accepted 3 August 1992.
Correspondence: Dr S. J. Cross, Department of Cardiology, Aberdeen Royal Infirmary, Foresterhill, Aberdeen AB9 2ZD, Scotland. U K
Abstract
Patent foramen ovale is detected in-vivo using the technique of contrast echocardiography. A positive test depends on the ability of an observer to recognise micro-bubbles passing from the right to the left heart, and to differentiate them from background noise and/or chordae tendinae.
To assess the inter- and intra-observer variability of this technique four observers reviewed independently, and on two separate occasions, 100 consecutive contrast studies stored on video tape.
The proportions of agreement (95% CI) for each separate observer on the two occasions for the presence of patent foramen ovale were 0.91 (0.76–0.98), 0.88 (0.73–0.92), 0.80 (0.63–0.92) and 0.78 (0.60–0.91), and for its absence were 0.96 (0.88–0.99), 0.95 (0.87–0.99), 0.90 (0.81–0.96) and 0.91 (0.82–0.96), respectively. The proportions of agreement (95% CI) between all observers on the first viewing were 0.78 (0.72–0.84) for the presence and 0.91 (0.87–0.93) for the absence of patent foramen ovale. For the second viewing these were 0.81 (0.75–0.86) and 0.91 (0.88–0.94), respectively (P = NS, Chi-squared test).
These results indicate that contrast echocardiography is subject to clinically acceptable inter- and intra-observer variability.
Key Words: Contrast echocardiography • patent foramen ovale