Purpose: To define the value of Tei index according to severity of the disease and find out the relationship between Tei index and some hemodynamic parameters in estimation of pulmonary artery pressure by heart ultrasound. Patients: 246 patients with isolated ventricljlar septal defect (VSD) who were treated in Vietnam National Pediatric Hospital and 121 normal children. Method: Cross-sectional description. Result: Left ventricule Tei index of VSD patients is elevated in comparision with normal children (p0.05), but there was no significant difference between patient groups. On the other hand, Tei index of right ventricular is normal in VSD group without pulmonary hypertension, but it is high in the severe group with moderate hypertension, and especially high in the group with bidirectional shunt and severe hypertension (p0.001). Tei index of right ventricule elevated by 0.01 will make the risk of pulmonary hypertension increase by 19.8 times. Right ventricule Tei index of 0.58 may predict bidirectional VSD with sensitivity of 64 percent and specificity of 80 percent. Conclusions: Increased Tei index of left ventricule is related to left ventricular dilatation
increased Tei index of right ventricule is related to pulmonary hypertention.