Clinical Research On Screening And Diagnosis Of Fetal Congenital Heart Disease By Four-chamber View

Background:Fetal echocardiography is one of precise measurements in diagnosing congenital heart disease (CHD), which is one of the most common birth defects and greatly impairs health conditions of human being. Current perinatal cardiology, with fetal echocardiography as its core technology, is based on the concept of second level prevention and figure out CHD as early as possible through prenatal screening and diagnosis. A four-chamber view of the heart has been proposed as a routine portion of the sonographic examination of the fetus as a satisfactory four-chamber view may be obtained in 97.64% of pregnancies. Therefore, for routine obstetric sonography, the four-chamber view is the simplest. A four-chamber view shows almost all structures of the fetus heart except pulmonary artery, aorta artery, pulmonary valve and aortic valve. It can indicate cardiac structural abnormalities in about 60% fetuses affected with CHD. The dimension and proportion of heart chambers will alter in fetuses with cardiac structural abnormalities when compared to normal ones. Therefore, normal values of dimension and proportion of heart chambers in four-chamber view are needed for to establish diagnosis standard. Clinical research on screening and diagnosis of fetal congenital heart disease by four-chamber view will be performed.Methods:1310 normal singletons undergoing fetal echocardiogram at the Second Affliated Hospital of Central South University from 2005 to 2010 and 221 singleton fetuses with CHD diagnosed by prenatal echocardiogram and confimed by autopsy or echocardiography were recruited. A standardized four-chamber view was obtained in a horizontal section, just above the region of the diaphragm with Sequoia 512 and Voluson 730. Fetal echocardiographic measurements included right and left atrial diameters at end-systole(LAD, RAD), right and left ventricular diameters(LVD, RVD) at end-diastole and foramen oval diameter. Various CHD anomalies in the four-chamber view were analysed.Results:The LVD of the 1310 normal fetus increased from 5.05mm at 16 weeks' gestation to 16.09mm at term. The RVD increased from 5.55mm at 16 weeks' gestation to 16.71mm at term. The LAD increased from 4.71mm at 16 weeks' gestation to 14.91mm at term. The RAD increased from 4.99mm at 16 weeks'gestation to 15.46mm at term. A simple, linear regression model was the best description of fetal cardiac measurements and gestation. The correlations were excellent. RVD/LVD is 1.05 and RAD/LAD is 1.05, which have no correlation with gestation. When only the four-chamber view was visualized, 117 of 221 fetuses (53%) with confirmed abnormalities including cardiac axis deviation, structure abnormality, difference in size of the atrial or ventricular chambers and doppler abnormality.Conclusion:For routine obstetric sonography, the four-chamber view has been proved as simplest, and yet highly accurate method of detecting significant CHD such as single ventricular, single atrial, atrioventricular septal defect, Ebstein's anomaly, heart mass, hypoplasia of the right and left ventricular. It laid clues for obstructive lesions of the ventricular outflow tract and anormaly of the great artery. Thus, the four-chamber view could probably be used as part of routine screening for CHD. The obtained cardiac dimensions in normal fetal hearts can supply diagnosis guideline for difference in size of the atrial or ventricular chambers.