Introduction : LV remodeling after acute myocardial infarction has important clinical implication. Large number of studies demonstrated that LV remodeling was associated with higher incidence of adverse event. LV dyssynchrony immediately after acute myocardial infarction was not fully evaluated yet. We investigate prognostic relevance of LV systolic dyssnchrony as indictor of LV remodeling after acute myocardial infarction. Methods : We enrolled 92 patients (male 72.8%, Age 61.0짹13.0 yr) with acute myocardial infarction who underwent successful percutaneous coronary intervention in CNUH. We checked baseline characteristics, laboratory and echocardiographic findings. And we performed follow up echocardiography after 6 month. We divided patients into two groups as presence of LV remodeling which defined as increment of LV end systolic volume (LVESV) more than 20% compared with baseline exam. We analyzed various parameters including clinical, laboratory, angiographic and echocardiographic findings. Results : 27 patients (29.3%) developed LV remodeling after 6 month follow-up. There was no statistically significant difference in clinical and angiographic findings between two groups. In laboratory findings, LV remodeling group had higher peak CK-MB (149.9짹155.0 vs 74.6짹69.7, p=0.001) and Troponin-I (70.2짹73.3 vs 43.2짹39.5, p=0.024) level. In echocardiographic findings, baseline LV ejection fraction (EF) and LV end systolic volume (LVESV) showed no significant difference (LVESV :73.0짹37.3 vs 91.3짹52.0, p=0.013 and EF : 58.3짹13.3 vs 55.6짹11.8, p=0.329) between two groups. The degree of LV dyssnchrony which assessed by tissue Doppler imaging was significantly higher in LV remodeling group (75.2짹43.4 vs 38.3짹32.5) and independent predictor for LV remodeling in multivariate analysis (HR=0.134, p<0.001). In ROC curve analysis, AUC was 0.754 and cutoff value of 45.9 could predict the development of LV remodeling with 74.1% sensitivity and 72.3% specificity. Conclusion : The presence of LV dyssynchroncy immediately after myocardial infarction was important predictive factor for development LV remodeling.