Abstract 2916: Contraction Front Mapping in Detection of Ischemia during Live 3-Dimensional Dobutamine Stress Echocardiography
Background: Qualitative evaluation of ischemia by 3D Dobutamine stress echocardiography (3DDSE, Philips 7500) has significant interobserver variability. Contraction front mapping (CFM, Tom Tec Research Arena), analyzes temporal and spatial activation of LV contraction, and displays a bulls eye plot of the contraction wave front of the myocardial segments that reach peak contraction every 25 milliseconds. CFM has the potential to provide quantitative analysis of LV contraction.
Methods: Thirty patients(pts), age range 32 to 89 yrs, with coronary angiograms had 3DDSE. LV wall motion and CFM were analyzed by two different observers. Contraction time index (CTI) was measured as a standard deviation of the time to reach peak contraction in 16 myocardial segments. A > 10% increase in CTI from baseline to peak stress was considered abnormal.
Results: Sixteen of 30 pts had angiographic coronary artery disease (CAD). All 16 pts with CAD had an increase in CTI (mean ± SD) from 6.94 ± 2.39 at baseline to 8.82 ± 2.34 at peak stress (sensitivity 100%); stress induced wall motion abnormality in 3DDSE was seen in 14 of 16 pts (sensitivity 87.5%). In 14 pts without CAD, CTI decreased in all pts from 6.81 ± 3.66 at baseline to 4.73 ± 1.77 at peak stress; 3DDSE was negative for ischemia in 11 pts and nondiagnostic in 3 pts. The overall concordance between qualitatively assessed 3DDSE and the CTI response during stress was 83.3%.
Conclusions: The preliminary data suggest that contraction front mapping offers a novel and a potentially quantitative approach in evaluation of ischemia during 3DDSE.