Transpulmonary contrast echocardiography: effects on delineation of endocardial border, assessment of wall motion and interobserver variability in stress echocardiograms of limited image quality.

Background: A major limitation of stress echocardiography remains poor image quality.

Objective: To investigate the effects of transpulmonary contrast echocardiography (TCE) with BY 963 on endocardial border delineation, detectability of wall motion abnormalities and interobserver variability at rest and during dobutamine stress echocardiography (DSE) in subjects with technically limited baseline echocardiograms.

Methods: BY 963 was administered intravenously to 36 patients (5 ml for parasternal LAX/SAX, 10 ml for apical four-chamber/two-chamber view) both at rest and at peak stress during DSE. Two observers applied a delineation score (0, endocardial border not visible; 1 border poorly visible; and 2, border clearly visible) to 12 wall segments in the parasternal and 10 in the apical views both before and after administration of BY 963. A 16-segment wall-motion score was used.

Results: In parasternal views, the delineation score was not improved by TCE. In the apical views, TCE significantly increased the delineation score (from 14.1 +/- 5.4 to 20.7 +/- 4.2 at rest and from 14.6 +/- 5.7 to 21.7 +/- 4.1 under stress, both P< 0.01). For 18 of 25 patients with coronary artery disease (> or = 70% stenosis) results of DSE were positive before TCE, whereas results were positive for 21 patients during TCE. For 10 of 11 patients without coronary artery disease, results of DSE were negative both before and during TCE. For the apical delineation score, interobserver variability was decreased significantly by TCE (from 19.5 +/- 19.6 to 8.2 +/- 15.6% at rest and from 20.2 +/- 19.6 to 3.3 +/- 11.4% at peak stress, both P< 0.01).

Conclusions: TCE enhances endocardial border delineation in apical views at rest and during DSE, resulting in a decrease of interobserver variability and an improvement in assessment of wall motion. Use of TCE, at least how it was applied in this investigation, seems not to be indicated for parasternal projections.