Real-time Three-dimensional Echocardiographic Assessment Of Left Ventricular Volume In Healthy Fetuses

Evaluation of the fetal heart constitutes one of the critical areas of the prenatal diagnosis, fetal echocardiography acts as a window to the developing heart, With the fetal echocardiography in the application of the fetal cardiac examination increasingly sophisticated, it will provide a new means for prenatal ultrasound diagnosis of fetal complex congenital heart disease, and has very important significance to improve the quality of perinatal survival and quality of the population. The purposes of this study were to evaluate the feasibility and accuracy of real-time three-dimensional echocardiography (RT3DE) for quantifying the left ventricular volume in fetuses.Materials And MethodsFrom October 2008 to June 2009, A total of 222 pregnant women were randomly selected after they provided informed consent. Five twin pregnancies were excluded from the study. Only the cases with clear three-dimensional images for heart were included for final statistical analysis, thus, the study subjects consisted of 181 singleton fetuses with gestational ages between 20 and 40 weeks (mean 29.6±4.2 weeks). The biparietal diameters for fetuses were 46.8～97.4 millimeter (mean 76.8±10.7 millimeter), the ratios of fetal heart to fetal chest were 0.12～0.33 (mean 0.20±0.04), and the fetal heart rates were 120～165 beats per minute (mean 146.6±9.3 beats per minute). The maternal ages were 21～40 ages (mean 28.2±3.7 ages). The 181 cases were the fetuses with normal heart rate (regular rhythm) and normal anatomy. Full volume three-dimensional, two- dimensional (2D) and M-mode images were acquired by using a Philips iE33 system and data was processed offline using QLAB analysis software. Left ventricular end-systolic volume (ESV) and end-diastolic volume (EDV) were measured using semiautomated border detection echocardiographic techniques, and compared with 2D biplane Simpson's method and M-mode Teichholz formula.ResultsIn 181 healthy fetuses,the highest concordance correlation ((R2=0.975 for EDV, R2=0.982 for ESV; P<0.001) was noted between 2D biplane Simpson's and RT3DE-derived values with a small bias (0.332 ml for EDV,0.135 ml for ESV). The Bland-Altman analysis showed that FV3DE had the best reproducibility than M-mode Teichholz formula and 2D biplane Simpson's method. Intra-and interobserver error of EDV were 2.85% and 4.22% for RT3DE,8.37% and 8.98% for 2D biplane Simpson's rule,30.63% and 54.70% for M-mode Teichholz formula. Intra-and interobserver error of ESV were 2.34% and 6.14% for RT3DE,6.26% and 11.7% for 2D biplane Simpson's rule,43.06% and 66.03% for M-mode Teichholz formula.ConclusionRT3DE is a novel technique that can be more accurate than conventional methods in quantification of fetal left ventricular volumes, it may in future provide new insight into evolving fetal cardiac structure and function.