Qualitative real-time cross-sectional echocardiographic imaging of the human fetus during the second half of pregnancy

Congenital heart disease and extracardiac anomalies: associations and indications for fetal echocardiography

Fetal echocardiography is a well-established technique for the prenatal identification of congenital heart disease. One of the indications for its use is the presence of extracardiac anomalies, as such coexistent defects may have important implications for obstetric and neonatal management. We have reviewed the obstetric and pediatric literature to examine reported associations. If a fetus is suspected to have hydrocephalus, microcephaly, holoprosencephaly, agenesis of the corpus callosum, Meckel-Gruber syndrome, esophageal atresia, duodenal atresia, diaphragmatic hernia, omphalocele, or renal dysplasia, cardiac evaluation should be pursued. Furthermore, echocardiography may be of help in differential diagnosis of some anomalies (for instance, skeletal dysplasias). Maternal diabetes and phenylketonuria, as well as exposure to phenytoin, trimethadione, or isotretinoin, may result in multiple systemic defects, including congenital heart disease.

Fetal echocardiography. V. M-mode measurements of the aortic root and aortic valve in second- and third-trimester normal human fetuses

The aortic root dimension and aortic valve excursion of 43 normal fetuses were recorded with M-mode echocardiography and the measured dimensions correlated with noncardiac measurements (biparietal diameter, head circumference, abdominal circumference, and femur length) and cardiac measurements (diastolic biventricular inner dimension, diastolic left ventricular internal dimension, and mitral valve excursion). The correlation coefficients for the aortic root dimension ranged between 0.87 and 0.95, while those for the aortic valve excursion ranged between 0.78 and 0.87. Regression analysis demonstrated that the best fit of the data was a linear model from which the 5% and 95% confidence limits were computed for individual predictions of aortic root dimension and aortic valve excursion from noncardiac and cardiac measurements.

Echocardiographic techniques for assessing normal and abnormal fetal cardiac anatomy

Diagnostic quality images of the fetal heart in utero can be obtained as early as 18 to 20 weeks of gestation. The cardiac structures can be imaged primarily by cross-sectional echocardiography and augmented by a combination of simultaneous M-mode echocardiography and range-gated pulsed Doppler ultrasonography. Cross-sectional images from planes through the fetal heart equivalent to planes that can be obtained after birth can be generated in utero. In a study of 168 pregnancies, 10 structural cardiac abnormalities have been defined. These abnormalities and others that have been reported indicate the potential for in utero cardiac diagnosis. The recognition of structural congenital heart disease in utero has been helpful in genetic counseling, planning the method of labor and delivery and making decisions regarding termination of pregnancy and planning postnatal care. Fetal echocardiography offers the potential to change the pattern of health care delivery to those with suspected congenital heart disease.

Left atrial isomerism associated with asplenia: prenatal echocardiographic detection of complex congenital cardiac malformations

Complex congenital heart disease with suspected isomerism of the atria was diagnosed in two fetuses of 20 and 29 weeks' gestation using two-dimensional and M-mode scanning techniques. The first pregnancy was terminated at 21 weeks' gestation and stillbirth occurred at 31 weeks' gestation in the second pregnancy. At postmortem examination, a thoracoabdominal discordancy was found; the spleen was absent and the arrangement of the abdominal vessels was as anticipated for asplenia, but the thoracic situs revealed a bilateral right-sided arrangement with left isomerism of the atria. The heart, otherwise, showed complex abnormalities as anticipated for asplenia.

The role of diagnostic ultrasound in the study of fetal cardiac abnormalities

Between January 1982 and April 1983, a total of 315 patients was scanned for fetal Congenital Heart Disease (CHD). In 70% of these patients, there was an increased risk for CHD in their offspring, in the remaining 30% abnormal findings were made by ultrasound in the present pregnancy. Nine cardiac defects were correctly diagnosed. There were three false positive and three false negative findings. The presence of fetal dysrhythmia, Intra-Uterine Growth Retardation (IUGR), ascites or polyhydramnios warrants a structural analysis of the fetal heart. Prenatal scanning for CHD should preferably be carried out in centres which can guarantee a high degree of scanning experience, up-to-date scanning equipment and close cooperation with a well-established neonatal and pediatric cardiology unit.

In utero evaluation of fetal cardiac structure: a preliminary report

Fetal echocardiography as a tool for the prenatal diagnosis of cardiac structural abnormalities was utilized in 27 consecutive patients who were referred for evaluation. Four abnormalities were recognized prenatally and confirmed postnatally. A fifth was identified postnatally. The sensitivity and specificity of this diagnostic test were 80% and 100%, respectively. The utilization of this tool in a tertiary care setting by an adequately trained team has proved to be helpful and is recommended.

Arrhythmia and structural abnormalities of the fetal heart

Thirty fetuses with cardiac arrhythmias were referred for ultrasonography. This included cross sectional and M mode echocardiography and pulsed Doppler analysis of the fetal heart. Three types of arrhythmias were observed: ectopic beats, tachyarrhythmias, and bradycardia. Ectopic beats were associated with cardiac structural abnormalities in two cases, resulting in fetal death in one. Tachycardia was not associated with structural defect, but death from cardiac failure occurred in one patient. Transplacental treatment for tachyarrhythmia was not successful in our experience. In the group with bradycardia four cases had congenital cardiac abnormalities and the mortality rate was 50%. When a fetal cardiac arrhythmia has been established careful structural and rhythm analysis is of vital importance in facilitating prognosis, planning of time and mode of delivery, and monitoring of transplacental treatment where indicated.

Prenatal ultrasound diagnosis of congenital heart disease associated with intrauterine growth retardation. A report of 2 cases

Two fetuses with extreme growth retardation (IUGR) of 31 and 34 weeks gestation were studied using a combination of two dimensional echocardiography (2DE), pulse wave Doppler (PWD) and differential measurement of the instantaneous vessel diameter techniques. The first fetus was diagnosed as having univentricular heart or possible double outlet right ventricle (DORV). Descending aorta blood flow was reduced as was indexing for weight. The second fetus was diagnosed as having univentricular heart with periodic bigeminal and trigeminal rhythm. Descending aorta blood flow was measured on two occasions and was reduced both times. Indexing for weight was within normal limits the first time and showed gross reduction on the second occasion prior to fetal demise. Fetal death occurred in both cases at 34 weeks gestation. Cardiovascular evaluation in fetuses with IUGR is useful as the detection of severe congenital cardiac abnormalities may substantially alter the management of these pregnancies, in particular caesarean section may be avoided when the prognosis for the fetus is considered hopeless.

Fetal echocardiography. A tool for evaluation of in utero cardiac arrhythmias and monitoring of in utero therapy: analysis of 71 patients

Fetal echocardiographic studies were performed in 71 patients referred for evaluation of cardiac rhythm disturbances at 24 to 40 weeks' gestation. After 2-dimensional echocardiographic study of cardiac structure was performed, M-mode echocardiograms were analyzed for measurement of cardiac rate, atrioventricular contraction sequence, atrioventricular valve motion, and duration of postectopic pauses. Arrhythmias were diagnosed in 59 patients. In 34 patients with isolated ectopic beats, the arrhythmia resolved during later pregnancy in 26 or within the first 5 days of life in 8. Six patients had mild sinus bradycardia and 8 had frequent sinus pauses; all 14 had resolution of the arrhythmia during pregnancy. Sustained arrhythmias occurred in 11 patients. Deaths occurred when there was associated fetal congestive heart failure (hydrops fetalis), structural heart disease, or both. M-mode echocardiography diagnosed supraventricular tachycardia in 3 fetuses. The echocardiogram was used thereafter for monitoring transplacental digoxin therapy.

Antenatal real-time ultrasound diagnosis of a congenital cardiac malformation

A case is presented of the antenatal diagnosis of a congenital cardiac abnormality in the fetus of a narcotic dependent mother, diagnosed by two-dimensional echocardiography. Infants born to narcotic dependent mothers require intensive management for their withdrawal symptoms, which may include respiratory and feeding difficulties. Possible cardiac abnormalities may not be considered as a cause for these symptoms until more overt signs appear. The clinical course of infants with coarctation of the aorta, which occurs in 1/1600 live births, is related to the type and degree of coarctation and to the presence, or absence, of other cardiac lesions. Antenatal knowledge of a cardiac malformation should allow the planning of suitable modes of delivery and prompt treatment even before the onset of obvious clinical signs.

Computer analysis of cardiac contractility variables obtained by M-mode echocardiography in normal newborns

There are few echocardiographic studies which examine ventricular cavity and wall dimensions as well as ventricular function in normal newborn infants. We investigated the M-mode echocardiograms of 60 normal newborn infants aged 3 to 6 days using computer analysis. Using the same method, we examined in addition left ventricular cavity dimensions and contractility variables of 15 healthy newborn infants sequentially during the first hour of life. The left and right ventricular diameters, their systolic shortening fraction and maximal rate of change, as well as the thickness of the interventricular septum and the left ventricular posterior wall were found to be comparable to previously published values. In addition, we found that the left ventricular end-diastolic diameter and the systolic shortening fraction of the left ventricular diameter increase significantly during the first hour of life. This increase is probably because of the postnatal increase in left ventricular volume and pressure work.

Prenatal echocardiography

Congenital cardiac defects are not common, but their serious consequences make early detection and treatment essential. In developing a set of workable criteria for selective screening of serious abnormalities, the authors used commercially available ultrasound equipment in more than 500 high-risk pregnancies. Possible future applications include elucidation of causes of fetal cardiac defects.