Background: Abnormal septal motion after coronary artery bypass graft surgery (CABG) is a common finding. With Gated SPECT, assessment of cardiac function by assessing wall motion (WM) and wall thickness (WT) is made easy. Septal WM after CABG has been reported to impair. WT may be an alternative approach to functional assessment after CABG. We hypothesize that a recognizable pattern exists in polar map (PM) for postCABG septum (PCS) vs normal septum (NS). Aim of this study was to quantify septal WM and WT in relation to lateral wall using PM.Methods: Quantitative post stress gated SPECT (Autoquant -QGS(R)) functional raw data for motion (mm) and thickening (%) were analyzed in a four region PM in 30 postCABG patients. The endocardial WM from end diastole to end systole by the brightest color scale was equal to a 10 mm change. Similarly, WT change was expressed in percentage (%) (twice the end diastolic thickness at end systole =100%). Control group included 23 patients with normal myocardial perfusion. A ratio of septal and lateral WM and WT (SLWM & SLWT) was compared between the two groups.Results: Mean Age 58 +/- 10 years, 66% males. The results comparing QGS (SLWM & SLWT) in both groups are shown below. There was a significant difference (p-<0.001) in SLWM between the two groups. However it did not demonstrate a significant difference in SLWT (p-0.09).Conclusions: SLWM ratio in QGS can identify PCS. A value of 0.5 for SLWM is considered as a cut-off for PCS vs NS. This difference in retrospect corresponds to the color scale on the PM in QGS and demonstrates a recognizable pattern. SPECT VariablesCABG (n = 30)Control (n = 23)p-valueWM (mm) Septum2.51 +/- 1.966.54 +/- 1.65<0.001WM Lateral9.3 +/- 2.459 +/- 1.60.31WM Ratio of S/L0.3 +/- 0.280.73 +/- 0.15<0.001WT (%) Septum33.53 +/- 10.742.7 +/- 11<0.001WT (%) Lateral31.6 +/- 13.441.6 +/- 12<0.001WT Ratio of S/L1.32 +/- 0.941.05 +/- 0.210.09