Endocardial border delineation during dobutamine infusion using contrast echocardiography

Area of Science:

• Cardiology
• Medical Imaging
• Ultrasound Technology

Background:

• Pharmacologic stress echocardiograms often yield suboptimal images, hindering accurate wall-motion analysis.
• Second harmonic imaging, while advanced, may not fully overcome image quality limitations in some cases.
• Myocardial ultrasound contrast agents offer potential to improve endocardial border visualization.

Purpose of the Study:

• To evaluate the efficacy of continuous intravenous myocardial ultrasound contrast infusion in enhancing endocardial border delineation during dobutamine-atropine stress echocardiography (DASE).
• To assess the impact of contrast on image quality for wall-motion analysis in DASE procedures.

Main Methods:

• Prospective study of 68 patients undergoing DASE with continuous intravenous perfluorocarbon-exposed sonicated dextrose albumin (PESDA) microbubble contrast.
• Scalar dobutamine infusion (5-40 microg/kg/min) and atropine (up to 1 mg) were administered.
• Blinded reviewers assessed endocardial delineation using a 16-segment model, comparing images with and without contrast, and calculated an Endocardial Delineation Score Index (EDSI).

Main Results:

• Contrast-enhanced images showed significantly higher mean EDSI (2.22-2.29) compared to non-contrast images (1.30-1.46) (P < 0.05).
• 95% of segments were delineated with contrast versus 81% without contrast.
• Complete left ventricle opacification was achieved in all patients with a mean contrast dose of 4 mL/min.

Conclusions:

• Continuous intravenous myocardial ultrasound contrast significantly improves endocardial border delineation during DASE.
• Enhanced delineation facilitates more accurate wall-motion analysis in stress echocardiography.
• This technique represents a valuable advancement for improving diagnostic accuracy in DASE.