Objectives: Cardiovascular magnetic resonance-feature tracking (CMR-FT) enables quantification of myocardial deformation and may be used as an objective measure of myocardial involvement in ST-elevation myocardial infarction (STEMI). We sought to investigate the associations between myocardial dyssynchrony parameters and myocardium damage for STEMI.Methods: We analyzed 65 patients (45-80 years old) with anterior STEMI after primary percutaneous coronary intervention during 3-7 days [observational (STEMI) group] and 60 healthy volunteers [normal control (NC) group]. Myocardial dyssynchrony parameters were derived, including global and regional strain, radial rebound stretch and displacement, systolic septal time delay, and circumferential stretch.Results: CMR characteristics, including morphologic parameters such as left ventricular ejection fraction (LVEF) (45.3% +/- 8.2%) and myocardium damage in late gadolinium enhancement (LGE) (19.4% +/- 4.7% LV), were assessed in the observation group. The global radial strain (GRS) and global longitudinal strain (GLS) substantially decreased in anterior STEMI compared with the NC group (GRS: 19.4% +/- 5.1% vs. 24.8% +/- 4.0%, P < 0.05; GLS: -10.1% +/- 1.7% vs. -13.7% +/- 1.0%, P < 0.05). Among 362 infarcted segments, radial and circumferential peak strains of the infarcted zone were the lowest (14.4% +/- 3.2% and -10.7% +/- 1.6%, respectively). The radial peak displacement of the infarct zone significantly decreased (2.6 +/- 0.4 mm) (P < 0.001) and manifested in the circumferential displacement (3.5 degrees +/- 0.7 degrees) in the STEMI group (P < 0.01). As microvascular occlusion (MVO) was additionally present, some strain parameters were significantly impaired in LGE(+)/MVO+ segments (radial strain [RS]: 12.2% +/- 2.1%, circumferential strain [CS]: -9.6% +/- 0.7%, longitudinal strain [LS]: -6.8% +/- 1.0%) compared to LGE(+)/MVO- (RS: 14.6% +/- 3.2%, CS: -10.8% +/- 1.8%, LS: -9.2% +/- 1.3%) (P < 0.05). When the extent of transmural myocardial infarction is greater than 75%, the parameter of the systolic septal delay (mean, 148 ms) was significantly reduced compared to fewer degrees of infarction (P < 0.01).Conclusion: In anterior STEMI, the infarcted septum swings in a bimodal mode, and myocardial injury reduces the radial strain contractility. A more than 75% transmural degree was the septal strain-contraction reserve cut-off point.