Assessment of left ventricular wall motion and delineation of the endocardial border after intravenous injection of Infoson (TM) during dobutamine stress echocardiography

Objectives To investigate whether intravenous injection of Infoson(TM) faci litates the assessment of left Ventricular walt motion and definition of en docardial border and thereby reduces inter- and intra-observer variability during dobutamine stress echocardiography. Background Clear detection of the endocardial border is essential during do butamine stress echocardiography. Although several contrast agents have bee n tested for their efficacy in enhancing definition of left ventricular end ocardium, their usefulness during dobutamine stress echocardiography has no t been evaluated. Methods Thirty coronary artery disease patients underwent dobutamine stress echocardiography. Infoson(TM) was injected at 0.2 ml/kg in both apical fou r- and two-chamber views. Detection of the left ventricular endocardial bor ders was scored from 0 (undetectable) to 10 (best) and expressed as a perce ntage of image quality at rest and peak stress by two independent observers . Regional wall motion was also evaluated and the total wall motion score i ndex calculated each time. Results Delineation of the left Ventricular endocardium improved from 76 +/ - 4% to 84 +/- 2% at rest (P < 0.01) and from 75 +/- 4% to 89 +/- 1% at pea k stress (P < 0.01) after administration of Infoson(TM). The greatest impro vement was seen in the basal and middle regions of the lateral and anterior walls. Inter- and intra-observer Variability was reduced after administrat ion of Infoson(TM). At rest, the probability of concordance between two obs ervers increased from 0.86 (0.82-0.89) to 0.91 (0.88-0.94) (P < 0.05) and a t peak stress from 0.86 (0.82-0.9) to 0.90 (0.86-0.92) after administration of Infoson(TM) (P < 0.05). The probability of concordance between on- and off-line assessment by one observer also increased from 0.84 (0.8-0.88) to 0.90 (0.86-0.93) (P < 0.01) at rest and from 0.90 to 0.92 (NS) at peak stre ss. Overall, a change in wall motion score index occurred in 16 of 30 (53%) patients after administration of Infoson(TM), thus improving the accuracy of the stress test compared with coronary angiography. The wall motion scor e index was overestimated in 11 of 16 (37%) patients without Infoson(TM) wh ile the detection of new wall motion abnormalities increased in 5 of 16 (17 %) (P < 0.01). Conclusions Intravenous administration of Infoson(TM) facilitates the asses sment of wall motion, particularly of the basal lateral and anterior walls where endocardial border drop-out frequently occurs during dobutamine stres s echocardiography; it thus reduces the inter- and intra-observer variabili ty. Coronary Artery Dis 9:567-576 (C) 1998 Lippincott Williams & Wilkins.