Abstract 1866: Contraction Front Mapping in Estimation of Ischemic Burden During Live 3-Dimensional Dobutamine Stress Echocardiography
Background: Contraction front mapping (CFM) was applied in estimating the ischemic burden during 3D Dobutamine stress echocardiography (3DDSE) in pts with coronary artery disease (CAD).
Methods: Seventy-five pts, age range 39 – 89 yrs, with coronary angiograms had 3DDSE. CFM’s (bulls eye plot of LV contraction measured every 25 ms, Tom Tec) were obtained at baseline and at peak stress (peak). The pattern of CFM was correlated with coronary lesions, and ischemic burden was estimated as the % of segments with delayed contraction. Contraction time index (CTI) was a SD of the time to reach peak contraction in 16 myocardial segments. A > 10% increase in CTI from baseline to peak was considered abnormal.
Results: Thirty-eight of 75 pts with CAD increased CTI (mean ± SD) from 5.41 ± 3.27 at baseline to 8.19 ± 2.87 at peak (sensitivity 100%); stress induced LV wall motion abnormality was seen in 32 of 38 pts (sensitivity 84.2%). In 37 pts without CAD, CTI decreased in all pts from 5.12 ± 3.1 at baseline to 4.18 ± 2.72 at peak, 3DDSE was negative in 31 pts and non-diagnostic in 6 pts. Delayed contraction patterns were seen in left anterior descending artery (LAD) territory in all 5 pts with LAD disease (ds), in right coronary (RCA) territory in all 7 pts with RCA ds, and in multiple segments in 26 pts with multi-vessel ds. The ischemic burden (mean % ± SD) in 12 pts with single vessel ds was 11.16 ± 7.69 at baseline and 18.67 ± 14.71 at peak compared to 37.69 ± 15.16 at baseline and 51.41 ± 17.96 at peak in 26 pts with multi-vessel ds. (Figure⇓ shows ischemia in shades of red in LAD, RCA and multi-vessel ds.)
Conclusions: CFM is sensitive in detection of ischemia and provides a quantitative estimate of the ischemic burden.