Parameters evaluating left ventricular dyssynchrony on Gated-SPECT X +2SD of control group Group of patients after MI PSD 31.99 PSD ≥ 31.99 77% HBW 84.25 HBW ≥ 84.25 81% Peak 170.28 Peak ≥ 170.28 12% HK 46.88 HK ≥ 46.88 15% HS 6.03 HS ≥ 6.03 7% When taking the X + 2SD threshold of the control group as the abnormal threshold, the disease group had 77% of patients with increasing PSD and 81% of patients with increasing HBW.