Abstract: AIM: To explore the application of Tei index in assessing right ventricular function of patients with atrial septal defect (ASD) pre- and postoperatively and to evaluate short-term effects of interventional and surgical treatment. METHODS: Forty seven patients with ASD (26 with pulmonary hypertension) and 25 healthy subjects as controls were examined. Right ventricular diameter (RVDd), right ventricular ejection fraction (RVEF), pulmonary artery systolic pressure (PASP) and Tei index were measured by Doppler echocardiography preoperatively and 3 months postoperatively. RESULTS: In comparison with control subjects, patients with ASD showed significantly higher diameter of the right ventricle and right ventricle Tei index. Compared with ASD patients without pulmonary hypertension, ASD patients with pulmonary hypertension showed significantly higher right ventricular diameter, ASD size and right ventricular Tei index. After intervention or surgical treatment, right ventricular Tei index of ASD patients without pulmonary hypertension was lower than before operation. Compared with those of healthy subjects, no statistical significance was found. After intervention or surgical treatment, right ventricular Tei index of ASD patients with pulmonary hypertension was lower than before operation, although it was still higher than in healthy subjects. CONCLUSION: Right ventricular function of ASD patients decreases. Short-term efficacy assessment shows that intervention or surgery significantly improves right ventricular function of ASD patients without pulmonary hypertension, but not that of ASD patients with pulmonary hypertension.