Quantification of right ventricular(RV)volume and function remains a challenge because of RV complex geometry by conventional echocardiography.The purpose of this study was to assess RV global longitudinal function in patients with tetralogy of Fallot(TOF)by 2-dimensional ultrasound speckle tracking imaging(STI).Thirty-eight patients with TOF were enrolled in this study and divided into child group(n=25)and adult group(n=13)according to age.Thirty-eight age-and sex-matched normal subjects were selected as control groups including child control group(n=25)and adult control group(n=13).RV global longitudinal peak systolic strain(GLS),strain rate(GLSPs),early diastolic strain rate(GLSRe)and late diastolic strain rate(GLSRa)were measured in all subjects by STI from the apical 4-chamber view and compared between groups.Furthermore,the main factors affecting the RV global longitudinal functional parameters were assessed.Compared with those in controls,RV GLS,GLSRs and GLSPe were significantly reduced in patients with TOF(P