Preliminary study of cardiac morphology and function in fetuses with tetralogy of Fallot using fetal heart quantification / 中华超声影像学杂志

ABSTRACT

Objective:To evaluate the fetal heart shape and function in tetralogy of Fallot (TOF) by fetal heart quantitative analysis (fetal HQ).Methods:A total of 52 fetuses with TOF diagnosed by fetal echocardiography and 200 normal fetuses matched with their gestational weeks from March 2020 to March 2022 at Sir Run Run Shaw Hospital, Zhejiang University were retrospectively evaluated. The basic parameters of fetal cardiac blood vessels in the two groups were measured by fetal HQ technology and conventional M-mode ultrasound technology aortic valve diameter(AV), pulmonary artery valve diameter(PV), main pulmonary artery diameter (MPA) and Z-score. The overall morphometric measurements including end-diastolic length diameter, transverse diameter, area, and global spherical index (GSI) of the fetal heart in the 4-chamber view(4CV), area and length of the right and left ventricles and their ratios. Measurements of left and right ventricular function included ejection fraction (EF), fraction area change rate (FAC), tricuspid annular plane systolic excursion (TAPSE), left and right ventricular global longitudinal strain (GLS), and left and right ventricular end-diastolic diameter (ED), spherical index (SI), and fractional shortening rate (FS) of 24-segments. The differences of above parameters between TOF group and control group were compared. In addition, the relationships between the absolute value of left and right ventricular GLS of TOF fetus and PV/AV, PV Z-score and MPA Z-score were analyzed. The optimal critical values of GSI, left ventricular EF and left ventricular FAC of TOF fetus were determined by ROC curve, and their corresponding sensitivity and specificity were obtained.Results:Compared with control group, there were significant differences in 4CV end-diastolic length, area, GSI, left ventricular area, left ventricular length, left ventricular EF, left ventricular FAC and left ventricular GLS in TOF group (all P<0.05). There were significant differences in ED between left ventricular 15-24 segments and right ventricular 1-21 segments (all P<0.05). There were significant differences in SI between left ventricular 1-16 segments, 21-24 segments and all segments of right ventricle (all P<0.05). The differences in FS were statistically significant (all P<0.05) when comparing all segments of the left ventricle and 1-2 segments of the right ventricular, and the remaining parameters were not statistically significant (all P>0.05). The left ventricular GLS absolute value of TOF fetuses was positively correlated with PV/AV, PV Z-score and MPA Z-score( rs=0.338, 0.441 and 0.458, all P<0.05), the right ventricular GLS absolute value of TOF fetuses was positively correlated with PV AV, PV Z-score and MPA Z-score( rs=0.418, 0.368 and 0.338, all P<0.05). The optimal critical values of GSI, left ventricular EF, and left ventricular FAC in the diagnosis of fetal TOF were 1.19, 59.05%, and 44.4%, respectively. At this time, the sensitivities of diagnosis of TOF were 0.78, 0.75, and 0.80, respectively. The specificities were 0.88, 0.88 and 0.83, respectively. The areas under ROC curve were 0.89, 0.88 and 0.89, respectively. Conclusions:Fetal HQ technology can provide a simple and reliable quantitative evaluation of fetal heart shape and function, and provide certain theoretical parameters for the study of fetal heart shape and function.