Abstract 8702: Assessment of Coronary Artery Disease by Contraction Front Mapping Analysis with Real Time Three-dimensional Stress Echocardiography with Adenosine: A Comparison with Thallium Scintigraphy

Abstract

Background: Stress echo with adenosine is not routinely used for the assessment of coronary artery disease (CAD) because of insufficient accuracy. Visual estimation of dyssynchrony with 2-D echo is often difficult because delays <70 ms cannot be detected with human eye. Contraction front mapping (CFM) constructed by real time 3-D echocardiography (RT3DE, ACUSON SC2000) with frame rate of 40 fps provides time-volume analysis for left ventricular (LV) volume, and enables us to assess LV dyssynchrony in only one heart beat. Thus, we evaluated usefulness of stress RT3DE for the detection of CAD. Methods : We performed scintigraphy and CFM at rest and stress with adenosine before angiography in 35 patients with suspected CAD. CFM can automatically divide LV into 16 segments, detect dyssynchrony and provide systolic dyssynchrony index (SDI) from the dispersion of time to minimum (min) regional volume for all 16 segments (average SDI) and maximum (max) dispersion of time to min regional volume (max SDI). Coronary angiography was served as a gold standard. Results : Images suitable for analysis were 34 (Figure). Heart rate and LV ejection fraction were increased at stress by 12% and 11% respectively. The prevalence of CAD was 76%. Diagnostic accuracy (88% for echo vs. 87% for scintigraphy), sensitivity (88% vs. 88%) and specificity (88% vs.85%) for the detection of CAD were similar between stress RT3DE and sintigraphy. There was no significant difference in the ability to detect single- or multi-vessel disease between RT3DE and scintigraphy. Although average SDI was similar at rest and at stress (6.6±4.0% vs.7.2±4.0%) max SDI was significantly increased at stress (22±10% vs. 18±8%, p<0.05). Conclusion: CFM constructed by stress RT3DE as a promising technique to quantify LV dyssynchrony in only one heart beat confers similar diagnostic accuracy in detection of CAD to scintigraphy and may be useful in the clinical setting for the evaluation of patients with suspected CAD.