摘要Background Frequent premature ventricular complexes from the right ventricular outflow tract (RVOT-PVCs) are associated with left ventricular dysfunction.This study adopted two-dimensional speckle tracking imaging to evaluate global and regional left ventricular myocardial function in patients with frequent RVOT-PVCs.Methods This study included 30 patients with frequent RVOT-PVCs and 30 healthy subjects.Aortic systolic velocity-time integral (AoVTI) and myocardium strain in circumferential (CS),radial (RS) and longitudinal (LS) directions were evaluated by conventional echocardiography and speckle tracking imaging.All values of patients with RVOT-PVCs were recorded during sinus (PVC-S) and PVC beats (PVC-V).Results Significant differences were demonstrated in global CS,RS and LS between the control subjects and the PVC-V (CS:(17.46±2.48)％ vs.(11.52±3.28)％,RS:(48.26±10.20)％ vs.(20.92±9.78)％,LS:(19.89±2.62)％ vs.(11.79±3.66)％,P ＜0.01),and in segmental RS and LS of nearly all the left ventricular segments.Statistical differences in segmental CS between the PVC-V and the control subjects were only observed in anterior,anteroseptal and septal segments (only seen in anteroseptal and septal segments at apex).Furthermore,V/S AoVTI (AoVTI during the PVC beat divided by AoVTI during the sinus beat,then multiplied by 100％) correlated with coupling interval (r=0.67,P ＜0.001) and global strain (CS:r=0.48,P=0.007; RS:r=0.65,P ＜0.001; LS:r=0.65,P ＜0.001).Conclusions Frequent RVOT-PVCs can induce global and regional left ventricular systolic dysfunction.The reduction of hemodynamic parameters relates to the coupling interval and the global systolic function.