Objective:To assess the association of time interval with surgical repair effects for patients with ventricular septal defect(VSD) following acute myocardial infarction(AMI).Methods:From January 2010 to December 2017, 14 patients with VSD induced by AMI have received surgical therapy in our department. The age of the entire group was (65.5±3.3) years with male percentage of 78.6%(11/14). VSDs were anterior apical in 10(71.4%) and posterior inferior in 4(28.6%) patients. Average size of VSD was(15.8±5.8)mm. We retrospectively reviewed the patients' clinical manifestations, surgical methods and outcomes. According to the time interval from AMI onset and operation, patients were divided into two groups, Group 1(9 cases) as more than one week and Group 2(5 cases) as less than one week. Comparing study was done and differences were analyzed.Results:All patients underwent concomitant coronary artery bypass graft surgery. The cardiopulmonary bypass time and aortic clamp time was(203.9±52.3)min and(152.4±44.8)min. The mortality rate was 14.3%(2/14), higher in Group 2 but no significant differences(20.0% vs 11.1%, P=1.000). Mechanical support(IABP and ECMO) were more common in Group 2, both in preoperative(IABP 80.0% vs 22.2%, P=0.091; ECMO 20.0% vs. 0, P=0.357) and intraoperative period(IABP 60.0% vs. 0, P=0.027; ECMO 40.0% vs. 0, P=0.110). Compared with Group 1, Group 2 revealed worse left ventricular function(LVEF 0.304±0.023 vs. 0.408±0.103, P=0.035), higher rate of urgent procedure(100% vs. 11.1%, P=0.003). No resistant shunt and death was found during follow-up. Conclusion:Surgery is an effective way to treat AMI with VSD. When the time from onset to surgery exceeds one week, the patient's hemodynamic condition is more stable and the operation is safer. Patients undergoing surgery within one week show more unstable hemodynamic status, and mechanical assistance supports can correct the hemodynamic status and improve perioperative success rate.