Background: The purpose of this study was to evaluate changes of right and left ventricular performances after volume-overload relief by transcatheter closure of ASD and to understand the factors that influence the changes of systolic and diastolic ventricular function by TDI. Methods: Fifty four ASD adult patients were divided according to age(���40 years and ���40 years) and Qp/Qs ratio(���2.5 and ���2.5). TDI was performed from 4 chamber view at pre-occlusion and, 1 and 6 months post-occlusion. Off-line measurement and analysis of myocardial performance index and isovolumic acceleration was performed. Results: In addition to RV volume relief, RV contractility improved after the procedure, but RV global dysfunction was evident in all the patients. We suggest that this phenomenon maybe due to physiological changes in mass/volume ratio following the relief of volume overload in RV. In patients older than 40 years, as well as patients with Qp/Qs ratio ���2.5, worsening of LV contractility was statistically evident. LV remodeling in these patients were probably inevitable, and when there is volume loading after the device closure, the subclinical dysfunction becomes prominent. Conclusion: In conclusion, a close observation of LV dysfunction in elderly patients and patients with large shunt is necessary, and this study can be proof that earlier intervention, while LV function is well preserved is called for in patients with secundum ASD.