Background There is paucity of data concerning the hemodynamic effect of delayed trans-catheter patent ductus arteriosus (PDA) closure. The current study tried to address this issueMethods This was a prospective observational study including 42 patients with mean age of 48 months and mean PDA diameter of 2.7±0.8 mm. The study group was subdivided into 2 subgroups (1st group less than and 2nd group more than 2 years of age at time of PDA closure). The 2 groups were assessed regarding the impact of PDA closure on different LV parameters measured by trans thoracic echocardiogram (2D dimensions, systolic function and 2D speckle tracking).Results LVEF in both groups decreased significantly immediately post PDA closure (p> 0.0001), but at 3 months follow up only in older group did it continue to be significantly lower than baseline values (p> 0.002). In group 1, indexed LVEDV and LVESV demonstrated significant early and continuous improvement at immediate and 3 months follow up (p>0.0001). Group 2 demonstrated only late improvement at 3 months follow up in indexed LVESV. GLS in both groups dropped significantly immediately post closure with significant improvement at 3 months follow up but GLS values remained significantly lower in group 2 compared to group 1 (p> 0.006). In both groups, age was positively correlated with percent reduction in GLS immediately post PDA closure and was negatively correlated with percent increase in GLS from immediate to 3 months follow up (degree of recovery). PDA size was negatively correlated with percent increase in LVEF from immediate to 3 months follow up (degree of recovery)Conclusion Trans catheter PDA closure in children 2 years old or less was associated with early reduction in LVEDV, LVESV, and greater improvement in LVEF and GLS after initial drop. It is crucial to diagnose and close hemodynamically significant PDAs as early as possible to ensure better LV reverse remodelling.