Atrial Isomerism

Introduction Heterotaxy (or situs ambiguus ) is defined as the abnormal arrangement of thoracic or abdominal organs, or both, across the left-right axis ( Video 90.1 ); it is different from complete situs inversus, which involves all organs. The term isomerism refers to the symmetric development of normally asymmetric organs or organ systems; this is the main feature of heterotaxy syndromes. These syndromes comprise a combination…

Double-Inlet Single Ventricle

Introduction Double-inlet single ventricle is a rare anomaly, accounting for 2% to 3% of all congenital heart diseases (CHDs). Double-inlet single ventricle comprises a heterogeneous group of cardiac anomalies characterized by the presence of two atria with a single ventricle. Cardiac and extracardiac anomalies are commonly associated. The prognosis is usually very poor, and univentricular repair is required. Disease Definition Double-inlet single ventricle comprises a heterogeneous…

Common Arterial Trunk

Introduction Common arterial trunk (CAT), also called truncus arteriosus, is an infrequent conotruncal anomaly in which there is a single outflow tract for both ventricles. Disease Definition CAT is characterized by a single great artery connecting both ventricles, which is responsible for the pulmonary, systemic, and coronary circulation ( Video 88.1 ). Prevalence and Epidemiology CAT accounts for 1% of all congenital heart diseases (CHDs), and…

Double-Outlet Right Ventricle

Introduction Double-outlet right ventricle (DORV) refers to a group of complex heart anomalies in which both great arteries arise entirely, or to a great extent, from the right ventricle. Disease Definition DORV encompasses a spectrum of lesions in which both outflow tracts connect to the right ventricle entirely or predominantly. Prevalence and Epidemiology DORV accounts for 4% to 8% of prenatal congenital heart diseases (CHDs). The…

Transposition of Great Arteries

Introduction There are two forms of transposition of great arteries (TGA): complete and corrected. Complete Transposition of Great Arteries A conotruncal anomaly characterized by a discordant ventriculoarterial connection. Complete TGA affects approximately 3 : 10,000 newborns. Definition Complete TGA is defined by normal atrioventricular concordance associated with an abnormal ventriculoarterial connection. The pulmonary artery arises from the morphologic left ventricle and the aorta emerges anteriorly from the morphologic…

Tetralogy of Fallot

Introduction Tetralogy of Fallot (TOF) is one of the most common conotruncal heart anomalies. It affects 9% to 11% of newborns with congenital heart disease (CHD). Disease Definition In TOF, there is an anterior-superior and leftward displacement of the outlet septum in relation to the trabecular interventricular septum. It is characterized by an outlet, perimembranous ventricular septal defect (VSD), an overriding aorta over the infundibular septum,…

Aortic Arch Anomalies

Introduction Aortic arch (AA) anomalies comprise a group of congenital alterations of the aortic arch that affect the position of the aortic branching. These anomalies can occur in association with other congenital heart diseases (CHDs) or as incidental findings in asymptomatic newborns. Disease Definition Most frequent AA anomalies include right aortic arch (RAA) anomaly and aberrant right subclavian artery (ARSA ) . RAA anomaly consists of…

Interruption of the Aortic Arch

Introduction Interruption of the aortic arch (IAA) is an uncommon ductal-dependent congenital cardiovascular malformation. It is the most severe form of aortic coarctation (AoC). Disease Definition IAA is characterized by the lack of continuity between the ascending and descending aorta. Prevalence and Epidemiology IAA accounts for 0.1% of all prenatally detected congenital heart diseases (CHDs) and 0.2% to 1% of postnatal CHDs, affecting 1 : 300,000 newborns. IAA…

Aortic Coarctation

Introduction Aortic coarctation (AoC) is a ductal-dependent heart anomaly characterized by a narrowing of the aorta. The presence of physiologic right-to-left shunts in the fetal circulation constitutes a challenge for prenatal diagnosis, making AoC one of the congenital heart diseases (CHDs) with the most common false-positive and false-negative diagnoses. Disease Definition AoC consists of a constriction on the aortic arch that causes obstruction of the blood…

Hypoplastic Left Heart Syndrome and Mitral Atresia

Introduction Hypoplastic left heart syndrome (HLHS) occurs in 0.1 : 1000 to 0.6 : 1000 live births and accounts for 2% to 3% of all congenital heart diseases (CHDs). HLHS is one of the most severe CHDs, with a high rate of perinatal death. Without treatment, it is responsible for 25% to 40% of all neonatal cardiac deaths. Disease Definition HLHS encompasses a spectrum of congenital heart malformations characterized by…

Aortic Stenosis and Aortic Atresia

Introduction Aortic stenosis (AS) affects 1.4 : 10,000 newborns. The spectrum of clinical manifestations varies widely according to the degree of valve stenosis. Disease Definition AS and aortic atresia encompass a group of congenital heart diseases (CHDs) characterized by left ventricular outflow tract obstruction. Depending on the level of the defect, these are classified as supravalvular, valvular, or subaortic obstruction. Valvular stenosis is the most frequently found form…

Pulmonary Stenosis and Atresia

Introduction Pulmonary stenosis (PS) and pulmonary atresia (PA) with intact ventricular septum have a low incidence in the fetus. In PS, there is a narrowing of the right ventricular outflow tract, whereas PA is characterized by an absent ventriculoarterial connection. The conditions are anatomically related, but the prognosis may vary substantially. Disease Definition PS refers to a narrowing of the right ventricular outflow tract secondary to…

Ebstein Anomaly and Tricuspid Dysplasia

Introduction Ebstein anomaly (EA) and tricuspid dysplasia (TD) are congenital heart diseases (CHDs) affecting the tricuspid valve and consequently all of the right heart. Although these anomalies are two different entities from an anatomic point of view, they share many pathophysiologic features. The clinical spectrum is variable depending on the degree of disruption of the valve anatomy. Prenatal forms usually belong to the severe spectrum. Disease…

Tricuspid Atresia

Introduction Tricuspid atresia (TA) is a rare form of congenital heart disease (CHD) that usually involves severe hypoplasia of the right ventricle. Prenatal diagnosis of TA and associated intracardiac and extracardiac anomalies is possible with a high degree of accuracy. Disease Definition TA is defined by the lack of connection between the right atrium and the right ventricle. The most common form is the absence of…

Atrioventricular Septal Defect

Introduction Atrioventricular septal defect (AVSD) is one of the most commonly diagnosed congenital heart diseases (CHDs) during fetal life and affects 4% to 5% of newborns with a CHD. AVSDs have a strong association with Down syndrome and frequently occur in combination with other CHDs. Disease Definition The term AVSD covers a spectrum of CHDs characterized by a common deficient separation in the atrioventricular junction. AVSD…

Ultrasound of Normal Fetal Heart

Introduction Congenital heart diseases (CHDs) are the most common severe congenital malformations, affecting 0.8% to 1% of newborns. Approximately half of the CHDs are severe defects. The overall mortality of a CHD diagnosed prenatally ranges from 25% to 35%, and about 15% of children born with a CHD die before they reach adolescence. Overall, the risk of associated chromosomal aneuploidy lies between 15% and 30%, with…

Congenital High Airways Obstruction Syndrome (CHAOS) and Bronchial Atresia

Introduction Congenital high airway obstruction syndrome (CHAOS) is a rare fetal anomaly that is associated with a high mortality (80%–100%). Prenatal diagnosis is clinically relevant in parental counseling and decision making regarding fetal surveillance, planning of fetal intervention, method of delivery, and postnatal management. CHAOS can be bilateral or unilateral (bronchial atresia). Disorder Definition CHAOS is an extremely rare condition consisting of complete intrinsic obstruction of…

Fetal Thyroid Masses and Fetal Goiter

Introduction The prenatal diagnosis of fetal goiter was first described in 1980. Advances in prenatal imaging and fetal hormonal physiology have enabled the identification of some severe but treatable disorders in the fetus. The potential benefits to the fetus of any prenatal treatment regimen must be carefully weighed against the potential risks to the fetus and the mother. Disease Definition Fetal goiter is an enlargement of…

Neck Teratoma

Introduction Fetal tumors are rare; teratomas are the most common histologic type. The neck is the most common location after the sacrococcygeal area for teratomas. The tissues found in fetal and infant teratomas are essentially the same regardless of the site of origin. A neck teratoma may be associated with neonatal mortality in 80% to 100% of cases if delivery is not managed properly. For large…