Analysis Of The Clinical Value Of VVI Technique In Assessing Right Ventricular Function In Patients With Thoracic Radiotherapy

Objectives:To explore velocity vector imaging（VVI）technique to evaluate the right ventricular function changes in patients with left lung cancer,left breast cancer and middle and lower esophageal cancer before and after radiotherapy.Methods:From May 2020 to May 2021,30 patients with left lung cancer,left breast cancer and middle and lower esophageal cancer in the Affiliated Hospital of Yanbian University were examined by echocardiography before and after radiotherapy.Conventional ultrasonic parameters were obtain edinapical four-chamber images including right ventricular basal diameter（RVD₁）,right ventricular middle diameter（RVD₂）,right ventricular longitudinal diameter（RVD₃）,fractional area change（FAC）,tricuspid annular plane systolic excursion（TAPSE）,peak systolic velocity（S’）,myocardial performance index（Tei）,isovolumic acceleration（IVA）.The VVI was used to measure the right ventricular free wall basal segment strain（RVLSbas）,right ventricular free wall intermediate segmental strain（RVLSmid）,right ventricular free wall apical segment strain（RVLSapi）,and the right ventricular free wall longitudinal strain（RVLSfw）and right ventricular systolic global longitudinal strain（RVGLS）were calculated.Then conventional parameters and strain parameters were compared before and after radiotherapy,and analyze the correlation between RVGLS,RVLSfw and each parameter.Results:1.After paired t test,there was nostatistically significant difference in RVD₁,RVD₂,RVD₃,S’before and after radiotherapy（P>0.05）,FAC,TAPSE,IVA values decreased,and Tei value increased,and the difference was statistically significant（P<0.05）.2.After paired t test,there were statistically significant differences in RVLSbas,RVLSmid,RVLSapi,RVLSfw,and RVGLS before and after radiotherapy（all P<0.05）.3.RVGLS was negatively correlated with FAC,TAPSE,and IVA（r=-0.56,-0.40,-0.37,P<0.05）,RVGLS was positively correlated with S’（r=0.39,P<0.05）,and RVLSfw was negatively correlated with TAPSE（r=-0.49,P<0.05）,RVLSfw was positively correlated with RVLSbas and RVLSmid（r=0.58,0.38,P<0.05）,and TAPSE was positively correlated with IVA（r=0.39,P<0.05）.Conclusions:1.The VVI technique can evaluate the early right ventricular local and global myocardial dysfunction in patients after radiotherapy for thoracic tumors.2.The parameters measured by ultrasound VVI technique have the good correlation with the conventional echocardiographic cardiac function assessment parameters.