OC174: The area behind the heart in the four‐chamber view and the quest for congenital heart defects

Abstract

To evaluate the spectrum of fetal cardiac defects associated with abnormal findings in the area behind the heart (ABTH) in the four-chamber view. This was a retrospective review of 393 cases with cardiac anomalies detected prenatally between 2003 and 2005 in a tertiary referral center. Some 4666 echocardiographies performed over a period of 15 months in 2006 and 2007, including 220 cases with cardiac anomalies were evaluated prospectively. In the study period 69 fetuses had abnormalities of the ABTH (75% with cardiac defects that warranted correction in the postnatal period). In 28 fetuses two equal-sized vessels were running behind the heart. Of these 26 had an aplasia of the hepatic segment of the vena cava inferior with azygos continuation (19 left isomerism with complex cardiac malformations, three left isomerism without cardiac defect, four isolated) and two had totally anomalous pulmonary venous drainage (both with right isomerism and complex cardiac malformations). In 41 fetuses only one vessel was visualized but the descending thoracic aorta was positioned contralateral to the cardiac apex. Of these 29 had levocardia with a right descending aorta. All of them were associated with a right aortic arch (23 with cardiac defects, six isolated). The remaining 12 had dextrocardia with left descending aorta (eight with cardiac defects, two with extracardiac malformations, two isolated). The ABTH in the four-chamber view is easy to evaluate and offers important diagnostic markers for fetal cardiac defects. Thus, it might enhance the screening performance of the four-chamber view. Attention has to be paid to the number of vessels and their laterality.