Coarctation of the aorta in prenatal life: an echocardiographic, anatomical, and functional study.

Abstract

SUMMARY In a prospective echocardiographic study of over 2000 pregnancies, 24 fetuses were found to have dilatation of the right ventricle and pulmonary artery when these structures were compared with those of the left heart. In 18 of these cases the diagnosis of coarctation or interruption of the aorta was correctly inferred from these findings. On direct echocardiographic examination of the aortic arch, arch hypoplasia or interruption of the aortic arch was recognisable prenatally in 10 of these 18 cases, most readily between 20-30 weeks' gestation. In 11 of 12 cases of aortic arch anomaly studied by Doppler echocardiography, a reduction in blood flow in the ascending aorta was demonstrated. The intracardiac appearances were suggestive of coarctation but the Doppler findings were within normal limits in two further cases which later proved to be normal. A diaphragmatic hernia was found in four fetuses and the intracardiac echocardiography and Doppler findings were the same as those found in fetuses with aortic coarctation. Five cases of coarctation were overlooked on the prenatal echocardiogram but these were found at follow up of the infants.Thus coarctation of the aorta can be diagnosed prenatally, although the condition may be missed or incorrectly predicted by the criteria examined in the present study. Reduced aortic blood flow is a demonstrable feature of aortic arch abnormalities but it is found in other conditions that are not associated with coarctation.During our total experience of fetal echocardiography we have had the opportunity to describe both normal and abnormal cardiac anatomy'2 and to follow the development of cardiac structure in the normal fetus.3 More recently we have been able to define the normal flow patterns during fetal life.4 Earlier in this programme we reported on the echocardiographic diagnosis and evolution of a case of coarctation of the aorta recognised initially at 20 weeks' gestation.' This case showed that coarctation of the aorta could be diagnosed prenatally but raised questions about the prevailing theories of its development. This case prompted a prospective study of the diagnosis of fetal coarctation in 2000 pregnancies that we subsequently examined and in which we studied development of the heart and great arteries in those suspected cases which went to term. Neonates were examined by a paediatric cardiologist or paediatrician. All fetuses that died in utero and the products of termination were examined at necropsy.The echocardiographic signs that we particularly noted were: (a) relative sizes of the right and left ventricles as measured at the level of the atrioventricular valve orifices in a frozen frame diastolic image of a four chamber view of the fetal heart (the range (mean (1 SD)) for this ratio, based on 80 normal fetuses is 1 1 (0 09)4); (b) relative sizes of the 356

Original paper. Do Umbilical Cord Wrapped Around the Fetal Body Can Mimic Signs of Aortal Coarctation?

“…by obtaining the four-chamber view, because examination shows that the right side of the heart is larger than the left and the disproportion is also seen in the great vessels in the mediastinum 4,5,6,7 . The inference is strengthened if there is disproportion between the pulmonary artery and the aorta with the PA/Ao ratio equal to or larger than 1,6 should alert about CoA 8,9 .…”

High‐definition flow combined with spatiotemporal image correlation in the diagnosis of fetal coarctation of the aorta

“…Prenatal suspicion of coarctation has been reported for 20 years 2 . However, despite a large number of publications, the prenatal diagnosis of this condition is still challenging.…”

In situ Morphology of Fetal Aortic Isthmus following Ductal Constriction in Rats

“…Clini cal observations also support this concept. Namely, intracardiac anomalies where blood is diverted away from the aorta to the pulmo nary artery tend to be associated with isthmus narrowing [5], In contrast, in congenital heart diseases with reduced pulmonary blood flow, the diameter of the aortic isthmus is wider than normal [4], Recent echocardiographic studies of human fetuses with coarctation of the aorta have revealed enlarged right ventricle and pulmonary artery [6], and smaller ascend ing aorta and aortic arch [6,7], These observa tions support the concept that coarctation of the aorta and isthmic hypoplasia are intimate ly related to decreased fetal isthmic flow.…”