Abstract 4237: Advances in Parametric 3D Echocardiography in Quantitative Estimation of Dobutamine Stress Induced Ischemia
Segmental and quantitative estimation of Dobutamine stress induced ischemia is now possible by 3D subtraction contraction front mapping (CFM - bulls eye dynamic plot of LV contraction measured every 25 msec, TomTec). Parametric 3D images of the LV segments were obtained at baseline and at peak Dobutamine stress in 68 pts (age 45 – 89 yrs). SDI (standard deviation of the time to peak contraction in 16 segments) and % delayed segments (% pixels activated after peak global systolic volume) were measured. Stress and baseline maps were subtracted pixel by pixel to obtain a subtraction CFM for measurement of stress induced ischemia. Figure⇓ shows baseline, peak stress and subtraction contraction front maps; blue - normal activation, red - delayed activation, purple - stress induced ischemia. Out of 45 pts with CAD, stress induced LV wall motion abnormality was seen in 2D Dobutamine stress echo in 34 pts (sensitivity 75%) compared to a > 10% increase in 3D SDI in 32 pts, (mean ± SD, SDI, 0.55 ± 0.4 at baseline, 0.63 ± 0.03 at peak, sensitivity 71%). In 23 pts without CAD, SDI decreased from 0.53 ± 0.02 at baseline to 0.3 ± 0.02 at peak, 2D DSE was negative in 21 pts and nondiagnostic in 2 pts. Percent ischemic segments (difference between stress and baseline segmental activation shown in purple in the subtraction map) were 9.62 ± 4.2 in pts with CAD compared to − 0.37 ± 3.48 in pts without CAD (p < 0.01) Dobutamine stress induced delay in LV segmental activation in pts with CAD can be mapped, quantified and displayed in real time. The technique provides an alternative 3D measurement of stress induced ischemia.