Abstract Aim: To detect the impact of elective PCI on left intraventricular mechanical dyssynchrony in patients with chronic stable angina. Methods: 100 patients with chronic stable angina were included and divided into two groups according to LV systolic and diastolic mechanical dyssynchrony measured by TSI 12-segments SD and Te-SD. 24 h then 1 month after PCI, patients with dyssynchrony were reclassified into improved vs persistent LV mechanical dyssynchrony. Results: At baseline 72% had LV systolic mechanical dyssynchrony. Patients with LV systolic mechanical dyssynchrony were significantly older (58.42± 4.617 vs. 54.64 ±3.456, respectively, p< 0.001), diabetic (36.11% vs. 14.3% p value < 0.05), higher prevalence of pseudo-normal and restrictive filling patterns (p value < 0.05), significantly larger LVESV (39.88 ± 13.67 vs. 32.93 ±9.79 ml, p< 0.05), lower EF% (54.13± 6.69% vs. 58.54± 6.4%, p value