OBJECTIVES: The aim of the study was to detect whether the systolic dyssynchrony index (SDI) assessed by real-time 3D echocardiography (RT3DE) could predict clinical outcomes of patients with ventricular aneurysm in response to surgical ventricular reconstruction (SVR). METHODS: In total, 120 individuals underwent RT3DE, including 30 healthy volunteers and 90 patients with ventricular aneurysm. All patients underwent clinical and echocardiographic assessments at baseline and at 12 months after SVR. The SDI was defined as the SD of time to minimum systolic volume of the 16 left ventricular (LV) segments, expressed in percent RR duration. SVR responder was defined as a > 15% decrease in LV end-systolic volume, reduction in NYHA functional class or 20% relative increase in the LV ejection fraction (LVEF). RESULTS: The SDI was significantly higher in patients with aneurysm, at 14.3% compared with 2.0% in healthy volunteers (P < 0.047). The SDI was negatively correlated with the LVEF. After SVR, 86 patients were responders. In this patient subgroup, the SDI exhibited an immediate significant decrease (to 7.7%; P < 0.034) and a progressive decrease during 12 months of follow-up (to 4.9%; P < 0.044). The SDI can discriminate SVR responders. Receiver-operating characteristic curve analysis yielded cut-off values of SDI 14.3% best associated with SVR response; area under the curve was 0.79 with reduction in NYHA class, 0.86 with increase in EF and 0.66 with decrease in the end-systolic volume. CONCLUSIONS: RT3DE can be used to assess LV mechanical dyssynchrony in patients with aneurysm. SVR produces a mechanical intraventricular resynchronization and SDI can predict improvement following SVR.