ABSTRACT
Objective:To investigate the application value of fetal heart quantification (fetal HQ) in the evaluation of fetal heart size, morphology and function in fetuses with right ventricular outflow obstruction (RVOTO).Methods:Fifty-five fetuses diagnosed as RVOTO by fetal echocardiography in Sir Run Run Shaw Hospital Affiliated to Medical College of Zhejiang University from April 2020 to February 2021 were selected. They were divided into simple pulmonary artery stenosis (PS) group and conus arteriosus malformation (CTD) group according to whether they were combined with other cardiovascular malformations. On the standard four chamber view, the end diastolic basal apical length (4CV length) and transverse width (4CV width) were obtained by fetal HQ analysis technique, and the cardiac global spherical index (4cv-gsi) was calculated. The left and right ventricles (LV and RV) were divided into 24 segments from the base to the apex. The endocardial curve was obtained by total HQ tracking. The 24 segment transverse width (ED), spherical index (SI), short axis shortening (FS) and its Z-score were calculated. The LV and RV of RVOTO fetuses were compared and analyzed from the aspects of heart size, morphology and function.Results:The 4CV length of RVOTO fetal heart was in the normal range, 4CV width increased in varying degrees, GSI decreased, and the whole heart showed spherical changes. In PS group, LV-ED was larger than that of RV and the difference was statistically significant in 5-24 segments( P<0.05). LV was more spherical than RV. There was no significant difference in ED between LV and RV in CTD group( P>0.05), and RV was more spherical than LV. Twenty-four segment FS decreased in different degrees in RVOTO fetal heart, and the decrease of RV was more obvious than that of LV. There was significant difference between the LV and RV in PS group from S5 to 19 ( P<0.05), and there was significant difference between the left and right ventricles in CTD group from S1 to 11 ( P<0.05). Conclusions:Fetal HQ can provide new insights of cardiac size, morphology and function in fetuses with RVOTO.