Congenital heart disease in the fetus

2. Broad based appendage
3. Receives coronary sinus
4. Connects to TV1. Sagittal
2. Sagittal
3. Four chamber
4. Four chamberLeft atrium1. Receives pulmonary veins
2. Finger-like long narrow-based appendage
3. Flap valve of FO floats inside
4. Connects to MV1. Four chamber
2. Parasternal short axis
3. Four chamber
4. Four chamberRight ventricle1. Receives TV
2. TV attachment to septum
3. TV more apically positioned
4. Moderator band
5. Coarse trabeculation
6. Connects to a bifurcating pulmonary artery1. Four chamber
2. Four chamber
3. Four chamber
4. Four chamber
5. Four chamber
6. Parasternal short axisLeft ventricle1. Receives MV
2. MV more basally positioned
3. MV attaches to the free wall only
4. Apex is wide open
5. Fine trabeculation
6. Connects to a non-bifurcating aorta with head and neck vessels arising from it1. Four chamber
2. Four chamber
3. Parasternal long axis
4. Four chamber
5. Four chamber
6. Parasternal long axisPulmonary artery1. Arises from an anterior ventricle
2. Bifurcates within first centimeter of its origin
3. Continues with DA into DAO1. Parasternal short axis
2. Parasternal short axis
3. Sagittal ductal archAorta1. Arises from a posterior ventricle
2. Branches out superiorly towards neck
3. In continuity with MV1. Parasternal long axis
2. Sagittal aortic arch view
3. Parasternal long axisDuctal arch1. Arises anteriorly with horizontal golf club appearance
2. Trifurcates with LPA and RPA, and DA
3. In continuity with DA and DAO1. Sagittal ductal arch
2. Sagittal ductal arch
3. Sagittal ductal archAortic arch1. Round “walking-stick” appearance
2. Gives off head and neck vessels
3. Arises from the middle of chest1. Sagittal aortic arch
2. Sagittal aortic arch
3. Sagittal aortic arch

DA, ductus arteriosus; DAO, descending aorta; FO, foramen ovale; IVC, inferior vena cava; LPA, left pulmonary artery; MV, mitral valve; RPA, right pulmonary artery; SVC, superior vena cava; TV; tricuspid valve.

Therefore, methodical application of other multiple scanning views should be utilized for accurate detection of all congenital heart anomalies (Table 8.2). In addition, M-mode, color flow, and pulse wave Doppler modalities (as deemed appropriate) should be employed when assessing integrity and function of those structures[14,15]. Measurement of cardiac structures should be performed in systole and diastole (Table 8.3 and Figure 8.1), and their values should be compared with established normal ranges in the corresponding gestation (Table 8.4)[15–18].

Table 8.2 The five fetal scanning views and likely cardiac anomalies detectable in each plane

Scanning view	Cardiac anomalies
A. Four-chamber view	1. Primum ASD 2. VSD 3. AVSD 4. Mitral or tricuspid atresia 5. Ebstein’s anomaly of the tricuspid valve 6. Enlargement of atriums and ventricles 7. Hypoplastic left or right ventricle 8. Atrial septal aneurysm 9. Double inlet left ventricle 10. Abnormal connection of pulmonary veins 11. Congenitally corrected TGA 12. Left superior vena cava to coronary sinus connection
B. Outflow tract views
I. Left ventricular outflow tract (parasternal long axis)	1. Aortic stenosis or atresia 2. TGA 3. Double outlet right ventricle 4. Truncus arteriosus 5. VSD 6. Left SVC to coronary sinus connection
II. Right ventricular outflow (parasternal short axis)	1. Pulmonary stenosis or atresia 2. Absent pulmonary valve syndrome 3. TOF 4. VSD
C. Three-vessel and trachea view	1. CoA 2. Vascular ring, double aortic arch or right aortic arch 3. Left SVC to coronary sinus connection 4. Pulmonary artery hypoplasia 5. Aortic hypoplasia 6. Ductal anomalies, abnormal, restricted or reversed ductal flow 7. TGA 8. TOF
D. Bicaval long-axis view	1. Interrupted IVC 2. Vein of Galen 3. Abnormal connection of pulmonary veins 4. Absent ductus venosus 5. Sinus venosus ASD 6. Restrictive FO
E. Ductal and aortic arch view	1. CoA 2. TGA 3. Hypoplasia of aorta or pulmonary artery 4. Interrupted aortic arch

ASD, atrial septal defect; AVSD, atrioventricular septal defect; CoA, coarctation of the aorta; FO, foramen ovale; IVC, inferior vena cava; SVC, superior vena cava; TGA, transposition of the great arteries; TOF, tetralogy of Fallot; VSD, ventricular septal defect.

Table 8.3 Cardiac structures and measurement sites

Cardiac Structures	Measurement Sites
Aortic annulus	At valve level, long-axis view
Ascending aorta	Above sinus of Valsalva, long-axis view
Descending aorta	Below entrance of ductus arteriosus, long-axis view
Ductus arteriosus	At its middle, short-axis view
Superior vena cava	At the entry into the RA
Inferior vena cava	At the entry into the RA
Aortic valve width	Aortic valve, short and long-axis view
Ascending ortic width	Aortic annulus, long-axis view
Main pulmonary artery	Above the annulus, short-axis view
Left and right pulmonary arteries	At origin, short axis view
Left and right ventricular width	Below coapted AV leaflets, four-chamber view
Ventricular free wall and septal thickness	Below coapted AV leaflets, four-chamber view
Left and right ventricular length	From the apex to the point of the coapted valve leaflets, four-chamber view
Left and right atrial width	From the lateral wall to the line between the two portions of the FO, four-chamber view
Left and right atrial length	From the coapted AV valve leaflet to the posterior wall, four-chamber view
Left ventricular width	Below coapted AV valve, from the septum to the posterior wall, long-axis view
Left ventricular length	From the apex to the point of coapted valve leaflets, long-axis view
Left atrial width	From the anterior to the posterior wall, long-axis view
Left atrial length	From the coapted MV leaflets to the top of the atrium
Right atrial width	From the lateral wall to the line between the 2 portions of the FO, short-axis view
Right atrial length	From the coapted TV leaflets to the posterior wall, short-axis view

AV; atrioventricular; FO, foramen ovale; MV, mitral valve; RA, right atrium.

Table 8.4 Normal dimensions of cardiac structures at 20 weeks

Examined cardiac structure	Normal value
Cardiac size
Cardiac/thoracic area ratio	0.25–0.35
Cardiac/thoracic circumference ratio	<0.5
Foramen ovale
FO diameter	0.28 ± 0.05 cm
FO Doppler velocity	<0.5 m/s
FO/right atrium diameter ratio	0.45 ± 0.01
FO/aorta diameter ratio	0.96 ± 0.16
FO/atrial septum length ratio	0.33 ± 0.04
Right heart
Atrial septal length	0.88 ± 0.13 cm
Right atrium transverse diameter	0.73 ± 0.08
Left/right atrium transverse diameter ratio	0.94
Tricuspid valve annulus	0.59 ± 0.11 cm
Tricuspid valve Doppler	0.52 ± 0.07 m/s
Tricuspid valve E/A ratio	0.64 ± 0.07
Right ventricle diastole	0.62 ± 0.11 cm
Right/left ventricle diameter ratio	1–1.2
Right ventricular free wall	0.23 ± 0.05
Pulmonary artery
Pulmonary valve	0.3 ± 0.05 cm
Pulmonary valve Doppler	0.55 ± 0.19 m/s
Main pulmonary artery	>0.3 ± 0.01 cm
Right pulmonary artery	>0.23 cm
Pulmonary/aorta size ratio	1–1.2
Left heart
Left atrium transverse diameter	0.68 ± 0.08
Mitral valve annulus	0.56 ± 0.09 cm
Mitral valve Doppler	0.45 ± 0.07 m/s
Mitral E/A ratio	0.63 ± 0.07
Left ventricular posterior wall	0.23 ± 0.05 cm
Interventricular septum	0.22 ± 0.05 cm
Left ventricle diastole	0.61 ± 0.12 cm
Left/right ventricle size ratio	0.97 ± 0.1
Fractional shortening	>28%
Aorta
Aortic valve	0.3 ± 0.05 cm
Aortic valve Doppler	0.6 ± 0.26 m/s
Ascending aorta	>0.3 ± 0.05 cm
Isthmus/ductus ratio	>0.74
Descending aorta	>0.25 cm
Ductus arteriosus
Three-vessel trachea view	>0.21 cm
Sagittal view	>0.21 cm
Ductus arteriosus velocity	0.6–0.8 m/s
Ductus/pulmonary artery diameter ratio	0.67± 0.1
Aorta/pulmonary artery ratio	0.92
Cardiac output
Right ventricular stroke volume	0.8 mL
Right ventricular output	110 mL/min
Left ventricular stroke volume	0.65 mL
Left ventricular output	88 mL/min
Right/left ventricular output ratio	1.2

E/A, early ventricular filling velocity/late ventricular filling velocity; FO, foramen ovale.

Figure 8.1

Measurement of cardiac structures. a) Measurement point of the four-chamber view in diastole and systole; b) from parasternal long axis view shows measurement of aortic valve and root; c) from parasternal short axis view shows aortic and pulmonary artery measurement points; d) from the ductal arch view shows ductus arteriosus, isthmus and descending aortic measurement points; e) from the aortic arch view shows isthmus and descending aortic measurement points; f) from the three vessel and trachea view shows measurement points of ductus arteriosus and the isthmus; g) from bicaval view shows measurement point of foramen ovale, IVC and SVC. LA, left atrium; RV, right ventricle; LV, left ventricle; AO, ascending aorta; PA, pulmonary artery; RPA, right pulmonary artery; LPA, left pulmonary artery; DA, ductus arteriosus; DV, ductus venosus; DAO, descending aorta; IVC, inferior vena cava; SVC, superior vena cava; FO, foramen ovale.

Ultrasound appearance of major cardiac anomalies and differential diagnosis

Normal fetal circulation

Figure 8.2

Normal fetal circulation. UV, umbilical vein; PoV, portal vein; DV, ductus venosus; HV, hepatic vein; IVC, inferior vena cava; RA, right atrium; LA, left atrium; RV, right ventricle; LV, left ventricle; AO, ascending aorta; PA, pulmonary artery; DA, ductus arteriosus; DV, ductus venosus; DAO, descending aorta; IVC, inferior vena cava; RPVs, right pulmonary veins; LPVs, left pulmonary veins; FO, foramen ovale.

The placenta is the main blood supply for the fetus. Its main function is to provide oxygenation for fetal venous blood. There are three unique fetal cardiovascular connections: the ductus venosus (DV) (a connection between the umbilical vein and the inferior vena cava (IVC)), the foramen ovale (FO) (a communication between the right (RA) and the left atrium (LA)) and the ductus arteriosus (DA) (a connection between the pulmonary artery and the aorta) (Figure 8.2). Increased oxygen tension in the ductal tissue promotes closure of the DA within a few days after birth. As the pulmonary vascular resistance drops, pulmonary arterial blood flow increases significantly, which in turn leads to increased pulmonary venous return to the LA. Due to increased left atrial pressure, the flap valve of the FO moves rightward onto the septum secundum resulting in functional closure of the FO.

Outline of antenatal and postnatal management of major cardiac abnormalities

From the sonographic diagnostic point of view, it is more logical to describe heart defects by their diagnostic anatomic features in specific scanning views (Table 8.5). Congenital heart defects can also be classified according to their clinical importance as severe, moderately severe and minor anomalies (Table 8.6). Clinical classification of cardiac anomalies determines the need for prostaglandin infusion or requirement of surgery at birth or in the infancy, thereby allowing the fetal medicine specialist to decide place of delivery. Generally, half of congenital heart defects are major (severe) requiring surgery within the first year of life. There is also a subgroup of life-threatening severe congenital heart defects, so called “ductus arteriosus dependent congenital heart anomalies” (Table 8.7), which most certainly require delivery at a surgical center and infusion of prostaglandin-E immediately after birth. If such anomalies escape detection antenatally or after birth, they may lead to cardiovascular collapse and sudden death following closure of the DA. Between 35% and 65% of pregnancies with major (severe) cardiac anomalies are medically terminated (Table 8.5), which might affect the postnatal frequency of a specific congenital heart defect (Table 8.8) [19–24]. Antenatal and postnatal management of major congenital cardiac anomalies are summarized in Tables 8.6 to 8.9 [25–39]. We will now describe each cardiac anomaly and its diagnostic features and long-term outlook in the following section.

Table 8.5 Diagnostic features of major cardiac anomalies, scanning views and detection and termination rates

Heart anomaly	Diagnostic features	Scanning views	Detection rate (%)	Termination rate (%)
Atrioventricular septal defect	1. Atrioventricular valves at the same level 2. Primum atrial septal defect 3. Common inlet valve 4. Most common abnormality inlet VSD 5. Left/right inlet valve regurgitation 50% 6. With tetralogy of Fallot 10–25% 7. With isomerism 15–20%	1. Four chamber 2. Short axis 3. Long axis	56–70	6–40
Ventricular septal defect	1. Communication between LV and RV 2. 75% perimembranous type: tetralogy, DORV 3. 10–15% muscular 4. 5% outlet: truncus 5. 5–8% inlet type: AVSD	1. Four chamber 2. Long axis	7–50	0–5
Hypoplastic left heart syndrome	1. Small LA and LV 2. Hypoplastic/stenosed/atretic aorta 3. Hypoplastic or atretic mitral valve 4. Check foramen ovale restriction 5. Check aortic arch coarctation 6. Check endocardial fibroelastosis	1. Four chamber 2. Five chamber 3. Long axis 4. Sagittal	63–95	36–63
Tricuspid atresia	1. Atretic right inlet valve 2. Small RV 3. VSD or intact ventricular septum 4. 25% TGA, 3% CCTGA	1. Four chamber	40–80	30–59
Total anomalous pulmonary venous connection	1. Small left-sided structures 2. Enlarged right heart 3. Increased flow from SVC, IVC	1. Four chamber 2. Long axis 3. Bicaval view 4. Sagittal view	0–12	0–10
Ebstein’s anomaly	1. Enlarged right atrium/enlarged heart 2. Apically displaced tricuspid valve 3. Severe tricuspid regurgitation 4. 30% VSD or PS 5. 30–50% accessory pathways/arrhythmias	1. Four chamber 2. Five chamber 3. Short axis	59–80	6–44
Double inlet left ventricle	1. Mitral and tricuspid valves open into a large single LV 2. RV hypoplastic 3. RV usually give rise to both great arteries 4. VSD	1. Four chamber 2. Five chamber 3. Short axis	30–50	51–55
Tetralogy of Fallot	1. VSD, 10% AVSD 2. PS/regurgitation 3. Hypertrophied right ventricle 4. Aortic override <50% 5. Right aortic arch >25% 6. Small ductus in 70% and not visualized in 30%, LSVC in 10%	1. Four chamber 2. Five chamber 3. Short axis 4. Long axis 5. Three-vessel trachea	15–69	0–17
Truncus arteriosus	1. Single artery arises from both ventricles and overrides VSD 2. Truncal valve either narrow or leaky in more than 50% 3. Biventricular hypertrophy 4. VSD, right aortic arch 33%, interrupted aortic arch 10–20% 5. PA arises from the main trunk	1. Four chamber 2. Five chamber 3. Short axis 4. Long axis	18–50	20–35
Double outlet right ventricle	1. Both great arteries arising from RV 2. VSD subaortic 47%, subpulmonary 23% 3. PS 4. TGA	1. Four chamber 2. Five chamber 3. Short axis 4. Long axis 5. Three-vessel trachea	50–65	31–56
Pulmonary stenosis or atresia	1. Pulmonary valve atretic or severely stenosed 2. RV hypoplastic or hypertrophied 3. VSD or intact ventricular septum 4. Major aortopulmonary collateral circulation	1. Four chamber 2. Short axis 3. Three-vessel and trachea	31–50	13
Transposition of the great arteries	1. Aorta arises from RV 2. PA arises from LV 3. Failure to show crossover of great arteries 4. VSD 40–45% 5. PS 30–50% 6. Coarctation or interruption 5%	1. Five chamber 2. Short axis 3. Long axis 4. Three-vessel and trachea	72–85	0–14
Coarctation/interruption of aorta	1. Small ascending aorta, VSD, bicuspid aortic valve 2. Small aortic isthmus (coarctation) 3. Discontinuity between transverse arch and descending aorta (interruption) 4. Large RV and PA compared with small LV	1. Five chamber 2. Long axis 3. Sagittal ductal arch 4. Sagittal aortic arch 5. Three-vessel and trachea	16–42	0–4

AVSD, atrioventricular septal defect; CCTGA; congenitally corrected transposition of the great arteries; DORV, double outlet right ventricle; IVC, inferior vena cava; LA, left atrium; LV, left ventricle; PA, pulmonary artery; PS, pulmonary stenosis; RV, right ventricle; SVC, superior vena cava; TGA, transposition of the great arteries; VSD, ventricular septal defect.

Table 8.6 Classification and ideal delivery place of babies with severe, moderate and mild CHD

Category	Anomaly
I. Severe CHD This category includes heart anomalies that require prostaglandin-E infusion at birth or operation in the newborn period. Therefore, delivery of a baby with such an anomaly should take place at a surgical center.	1. TGA 2. Pulmonary atresia 3. Absent pulmonary valve syndrome with severe stenosis 4. Hypoplastic right heart with severe PS 5. TA with restrictive FO, restrictive ventricular septum, severe PS 6. Hypoplastic left heart 7. Aortic atresia 8. Mitral atresia with restrictive FO, restrictive ventricular septum, severe PS or AS 9. Single ventricle (double inlet left ventricle) with severe PS or AS 10. Critical PS 11. Critical AS 12. TAPVC 13. Truncus arteriosus 14. Critical–severe CoA 15. Interrupted aortic arch 16. DORV with unrestricted pulmonary flow, severe PS or AS 17. Ebstein’s anomaly with severe tricuspid regurgitation and PS 18. TOF with absent pulmonary valve syndrome
II. Moderately severe CHD These anomalies do not require prostaglandin infusion at birth but some of them are expected to require surgery in the infancy. These babies need to be delivered at a tertiary cardiac center with or without surgical facility.	1. TOF 2. DORV with balanced pulmonary and systemic flow 3. Ebstein’s anomaly with mild-to-moderate tricuspid regurgitation 4. Double outlet left ventricle 5. CCTGA 6. AVSD 7. Large VSD 8. Mild-to-moderate AS or incompetence 9. Mild-to-moderate PS or incompetence 10. Noncritical coarctation 11. Vascular ring, double aortic arch
III. Mild CHD These patients do not require prostaglandin infusion at birth or surgery within neonatal period or in infancy. Therefore, these babies can be delivered locally. They are usually asymptomatic, and their cardiac anomaly may undergo spontaneous resolution, remain static or their progression is rather gradual over the years.	1. Small VSD 2. Atrial septal defect – primum or sinus venosus types

AS, aortic stenosis; AVSD, atrioventricular septal defect; CHD, congenital heart disease; CoA, coarctation of the aorta; DORV, double outlet right ventricle; FO, foramen ovale; PS, pulmonary stenosis; TA, tricuspid atresia; TAPVC, total anomalous pulmonary venous connection; TGA, transposition of the great arteries; TOF, tetralogy of Fallot; VSD, ventricular septal defect.

Table 8.7 Ductus dependent cardiac anomalies and their management

Cardiac anomaly	Antenatal management	Postnatal management
A. DA dependent systemic and pulmonary circulation 1. Transposition of the great arteries. B. DA dependent systemic circulation 1. Hypoplastic left heart syndrome 2. Critical aortic stenosis, 3. Aortic atresia 4. Coarctation of the aorta 5. Interrupted aortic arch C. Ductus arteriosus dependent pulmonary circulation 1. Critical pulmonary stenosis 2. Pulmonary atresia	The DA must remain open therefore avoid the use of ibuprofen, indomethacin, and discourage excess consumption of polyphenol rich food and drinks. The FO must remain open, hence monitor patency of the interatrial communication with bi-weekly ultrasound. Monitor pulmonary vein Doppler to help identify FO restriction in HLHS. Discuss at MDT meeting with neonatologist and pediatric cardiologist. Check karyotype to exclude 22q11 microdeletion in IAA, PS with VSD; Noonan syndrome in critical PS; Turner syndrome in coarctation; and William’s syndrome in supravalvar aortic stenosis.	Normal planned delivery with induction at 39 weeks in a surgical center if local facilities are away from a tertiary surgical center. Delivery at a nonsurgical center may be feasible if there is local pediatric cardiology service, local neonatal intensive care and neonatal transfer facilities are available. Prostaglandin infusion at 5–10 ng/kg/min should be started after birth. Avoid excess use of oxygen or unnecessary intubation. Oxygen saturations between 70–90% are acceptable. Nil by mouth until diagnosis is established and management plan is drawn

CoA, coarctation of the aorta; DA, ductus arteriosus; FO, foramen ovale; HLHS, hypoplastic left heart syndrome; IAA, interrupted aortic arch; MDT, multidisciplinary team; TGA, transposition of the great arteries.

Table 8.8 Major congenital heart anomalies, their frequency, birth incidence and outcomes

Heart anomaly	Fetal frequency among CHD %	Incidence in per 1,000 live birth	Outcome
Atrioventricular septal defect	5–16	0.19–0.35	1. <2% operative mortality 2. 95% survival at 20 year 3. 25% reoperation rate for AV valve regurgitation 4. 40% associated with Down’s syndrome, 20% trisomy 13 and 18
Ventricular septal defect	15–35	1.1–3.57	1.<2% operative mortality 2. Risk of complete heart block postoperatively 3. Excellent long term outlook
Hypoplastic left heart syndrome/ critical aortic stenosis	4–16	0.14–0.27	1. 20% IU death 2. >85% survival after stage 1 Norwood and >98% survival after Glenn and Fontan 3. 50% survival in 10 years 4. 15% association with chromosome abnormalities, Turner most common 5. Isolated aortic stenosis 25-year survival >70% 6. Need for repeat operation to replace aortic valve
Tricuspid atresia	1–3	0.03–0.5	1. >90% survival with arterial shunt, >98% survival with Glenn operation and >98% survival with Fontan operation. 2. 85% survival at 10 years 3. 8% associated with 22q11 deletion
Total anomalous pulmonary venous connection	0.6–3	0.06–0.09	1. Excellent long term outlook 2. 2% risk of pulmonary vein stenosis
Ebstein’s anomaly	0.3–0.7	0.06–0.11	1. IU mortality up to 45–100 % in severe cases, up to 90% survival in mild cases 2. May be associated with trisomy 21
Double inlet left ventricle	0.07–0.1	N/A	1. 10 year survival >70%
Tetralogy of Fallot	3–7	0.42	1. 8–23% 22q11 deletion, up to 75% if absent pulmonary valve syndrome 2. Tetralogy has excellent long term survival but up to 30% reoperation for PS or regurgitation 3. 30–50% mortality in absent pulmonary valve syndrome
Truncus arteriosus	3–4.8	0.05–0.11	1. 40% 22q11 deletion 2. 50% truncal valve regurgitation or stenosis 3. Early pre-operative death 5–10%, early survival 90% at 5 years
Double outlet right ventricle	2.4–12	0.16	1. Survival 70–80% at medium term
Severe pulmonary stenosis or atresia	2.4–6.5	0.16–0.26	1. PA-VSD 8–23% associated with 22q11 deletion 2. PS may be associated with Noonan’s, Alagille, and Leopard syndromes 3. Outlook is good in PS and tripartite right ventricle 4. PA-IVS survival 65% at 5 years and PA-VSD 70% survival at 10 years
Transposition of the great arteries	4.3–11	0.24–0.32	1. Excellent long term survival 97% at 10 years 2. Branch pulmonary artery stenosis 5–30%
Coarctation/interruption of aorta	8.9	0.14–0.41	1. 50% of interruption has 22q11 and 35% of Turner has coarctation 2. 25% associated with noncardiac anomalies 3. Excellent survival 4. 4% recurrence rate and reoperation risk, 25% risk of hypertension

AV, atrioventricular; CHD, congenital heart disease; IU, intrauterine; PA-VSD, pulmonary artery-ventricular septal defect.

Table 8.9 Antenatal and postnatal management of major heart anomalies

Cardiac defect	Frequency of antenatal scans	Antenatal management	Place of delivery	Postnatal management
Ventricular septal defect	20 weeks and 32 weeks	No special intervention	Cardiac center	No special intervention at birth. Monitor growth and signs of heart failure. Corrective surgery commonly within first year.
Atrioventricular septal defect	20 weeks and 32 weeks	Exclude trisomy 13, 18, 21, monitor size of right and left ventricles	Cardiac center	No special intervention at birth. Genetic review. Monitor growth and signs of heart failure. Corrective surgery mostly within 6 months.
Aorta-pulmonary window	20 weeks and every 4 weeks	No special intervention	Cardiac center	No special intervention at birth. Monitor growth and signs of heart failure. Corrective surgery within first few months.
Transposition of the great arteries	20 weeks and every 4 weeks	Monitor FO-DA patency, exclude PS and interrupted aortic arch	Surgical center	Prostin infusion and balloon atrial septostomy at birth. Corrective surgery-arterial switch within first few weeks of life.
Truncus arteriosus	20 weeks and every 2–4 weeks	Monitor truncal valve size, exclude truncal valve stenosis, regurgitation or interrupted aortic arch; offer amniocentesis to exclude 22q11 microdeletion	Surgical center	Prostin infusion if there is interrupted aortic arch. Check neonate calcium levels, monitor immunity and give Irradiated blood for when needed if 22q11 deletion present. Corrective surgery within first few weeks.
Total anomalous pulmonary venous connection	20 weeks and every 4 weeks	Determine site of connection of pulmonary veins, and presence of venous obstruction	Surgical center	No special intervention at birth. Corrective surgery within first few weeks.
Hypoplastic left heart	20 weeks and every 2–4 weeks	Monitor foramen ovale-ductus arteriosus patency, exclude CoA	Surgical center	Prostin infusion at birth. Three-stage palliative surgery (Fontan route): either Norwood, or Sanno or hybrid procedure as stage one at birth; SVC to-pulmonary artery shunt (Glenn) operation as second stage beyond 6 months of age and finally total cavo-pulmonary shunt (Fontan) operation at 5 years of age as the third stage.
Aortic atresia	20 weeks and every 2–4 weeks	Monitor FO-DA patency, size and function of left ventricle	Surgical center	Prostin infusion at birth. Corrective surgery within first few weeks of life.
Coarctation of the aorta	20 weeks and every 4 weeks	Monitor DA patency	Surgical center	Prostin infusion at birth. Blood pressure monitoring. Corrective surgery within first few weeks of life.
Interrupted aortic arch	20 weeks and every 4 weeks	Monitor DA patency; offer amniocentesis to exclude 22q11 microdeletion	Surgical center	Prostin infusion at birth. Blood pressure monitoring. Corrective surgery within first few weeks of life. Check neonate calcium levels, monitor immunity and give Irradiated blood for when needed if 22q11 deletion present.
Tetralogy of Fallot	20 weeks and 32 weeks	Monitor pulmonary artery size and growth; offer amniocentesis to exclude 22q11 microdeletion	Cardiac center	No special intervention at birth. Airway management and prevention of hypoxic spells. Check neonate calcium levels, monitor immunity and give Irradiated blood for when needed if 22q11 deletion present. Corrective surgery within first year.
Pulmonary atresia	20 weeks and every 4 weeks	Monitor FO-DA patency, pulmonary artery size and growth, size and function of right ventricle	Surgical center	Prostin infusion at birth. Three-stage palliative surgery within first five years: first few weeks of life aortopulmonary shunt operation; SVC-to-pulmonary artery shunt (Glenn) operation as second stage beyond 6 months of age and finally total cavo-pulmonary shunt (Fontan) operation at 5 years of age as the third stage. Corrective surgery may be possible if the right ventricle and pulmonary artery are of adequate size and they are in a connectable position.
Tricuspid atresia	20 weeks and every 4 weeks	Monitor FO-DA patency, pulmonary artery size and growth, size of VSD; determine origins of great vessels	Surgical center	Prostin if there is duct dependent heart defect or atrial septectomy if the foramen ovale is restrictive. Three-stage palliative surgery within first 5 years of life: first stage is at birth, aorto-pulmonary shunt operation if PS is severe or pulmonary artery banding if pulmonary flow is unrestricted; SVC-to-pulmonary artery shunt (Glenn) operation as second stage beyond 6 months of age and finally total cavopulmonary shunt (Fontan) operation at 5 years of age as the third stage.
Mitral atresia	20 weeks and every 4 weeks	Monitor FO-DA patency, pulmonary artery size and growth, size of VSD; determine origins of great vessels	Surgical center	Prostin if there is duct dependent heart defect or atrial septectomy if the FO is restrictive. Three-stage palliative surgery within first five years: first few weeks of life aorto-pulmonary shunt operation if PS is severe or pulmonary artery banding if pulmonary flow is unrestricted; SVC-to-pulmonary artery shunt (Glenn) operation as second stage beyond 6 months of age and finally total cavo-pulmonary shunt (Fontan) operation at 5 years of age as the third stage.
Ebstein’s anomaly	20 weeks and every 4 weeks	Monitor fetal heart rate and rhythm; size of right atrium, ventricle and pulmonary artery; pulmonary flow; severity of tricuspid regurgitation; cardiac function	Cardiac center	No special intervention at birth but prostin may be needed if pulmonary flow is not adequate. Surgery is determined by adequacy of pulmonary flow and degree of tricuspid regurgitation.

CoA, coarctation of the aorta; DA, ductus arteriosus; FO, foramen ovale; PS, pulmonary stenosis; SVC, superior vena cava; VSD, ventricular septal defect.

Intracardiac shunts that can be detected in four-chamber view

Ventricular septal defect

Ventricular septal defect (VSD) is a communication between the left and right ventricles (Figure 8.3). It is the most common of all congenital heart lesions and usually occurs as an isolated abnormality. It can also be associated with coarctation of the aorta (CoA), atrioventricular septal defect (AVSD), tetralogy of Fallot (TOF) and truncus arteriosus.

Figure 8.3

Ventricular septal defect. Left: from the four-chamber view shows a ventricular septal defect. Echocardiography on the right from the four-chamber view shows a ventricular septal defect. RA, right atrium; LA, left atrium; RV, right ventricle; LV, left ventricle; VSD, ventricular septal defect; FO, foramen ovale; PA, pulmonary artery; AO, aorta.

There are three major locations: underneath the inlet valves (perimembranous-inlet), in the middle of ventricular septum (muscular) and underneath outflow tracts (outlet). Muscular and perimembranous-inlet type defects can be detected in the four-chamber view, but the five-chamber, long-axis and short views are all needed to demonstrate the outflow defects. Color flow or pulse wave Doppler may aid in diagnosing smaller defects by showing bidirectional flow pattern across the ventricular septum. False-positive and negative rates are high.

The fetal clinical course is uncomplicated. The majority of small VSDs close spontaneously either in utero or after birth. It is important to exclude commonly associated defects such as CoA, TOF and truncus arteriosus.

Amniocentesis should be recommended for large VSDs located in inlet or outlet septum, to exclude 22q11 microdeletion and trisomy 21[38]. Delivery can take place at a local hospital if the VSD is an isolated anomaly regardless of its size.

Postnatally, no special precaution is needed in the newborn other than routine pediatric and cardiac review. A large VSD may lead to faltering growth and heart failure in infancy.

Treatment involves either stitch or patch closure of the defect with surgery. Some anatomically suitable defects may be amenable to device closure via percutaneous transcatheter approach. VSD has an excellent late functional and survival outcome after treatment.

Complete atrioventricular septal defect

AVSD has an atrial and ventricular communication with a common atrioventricular (AV) valve (Figure 8.4). In the incomplete form, there is an ostium primum atrial septal defect and a cleft mitral valve without a defect in the ventricular septum. This abnormality can be suspected from the four-chamber view by showing the left and right inlet valves being at the same level instead of having a normal off-setting appearance.

Figure 8.4

Atrioventricular septal defect. Diagram on the left from the four-chamber view shows atrioventricular septal defect. Echocardiography on the right from the four chamber view shows atrioventricular septal defect. RA, right atrium; LA, left atrium; RV, right ventricle; LV, left ventricle, ASD, atrial septal defect; VSD, ventricular septal defect; PA, pulmonary artery; AO, aorta.

Fetuses with this defect are commonly asymptomatic, but due to its frequent associations with chromosome abnormalities, amniocentesis is strongly recommended. Approximately 40–50% of fetuses with AVSD will have trisomy 21, 18 or 13. Likewise, 40–50% of fetuses with trisomy 21 will have AVSD. AVSD may also coexist with pulmonary stenosis in 2–10% of cases[36].

Postnatally, neonates with AVSD may be totally asymptomatic or only slightly cyanosed, and diagnosis in some cases may be overlooked. Any newborn with AVSD should have a careful pediatric, cardiac and if necessary, genetics review. Percutaneous oxygen saturation should be monitored after birth. Once the pulmonary vascular resistance drops, the neonates with a large VSD may develop respiratory symptoms, faltering growth and heart failure generally beyond 2 weeks of age.

Surgical repair of complete AVSD is usually undertaken before 6 months of age. After surgical repair, reasonable quality of life is expected, but there is a 20% re-operation rate for leaky inlet valves. However, if there is disproportionate ventricular size (unbalanced AVSD), the postnatal outlook is less unfavorable as the corrective two-ventricle repair cannot be achieved.

Anomalous pulmonary venous connection

In total anomalous pulmonary venous connection (TAPVC), some or all pulmonary veins fail to connect to the LA (Figure 8.5). Instead they may connect to the superior vena cava (SVC), RA, or into the liver either directly or indirectly via a common channel. An obstructed venous channel should be excluded. This abnormality is notoriously difficult to detect antenatally with no more than 6–10% detection rates. Presence of nonpulsatile pulmonary vein Doppler flow may alert the sonographer to this diagnosis.

Figure 8.5

Total anomalous pulmonary venous connection. Diagram on the left from the four chamber view shows supracardiac total anomalous pulmonary venous connection to the left brachiocephalic vein. Echocardiography on the right from the four-chamber view shows total anomalous venous connection to the left brachiocephalic vein. RA, right atrium; LA, left atrium; RV, right ventricle; LV, left ventricle; AV, ascending vein; LBCV, left brachiocephalic vein; SVC, superior vena cava; PV, pulmonary vein.

Fetuses with this abnormality are asymptomatic. TAPVC is rarely associated with chromosome abnormality. Usual prenatal follow-up at 4–6 weeks’ intervals is required.

Postnatally some of these patients may exhibit very little in the way of cyanosis, and diagnosis can easily be overlooked. If there is pulmonary venous obstruction, cyanosis will be accompanied by respiratory difficulties, which may frequently mimic persistent pulmonary hypertension of the newborn.

Surgical treatment involves re-implantation of pulmonary veins into the LA. Once corrected, most patients remain asymptomatic with no major long-term issues.

Outflow tract abnormalities

TOF and double outlet right ventricle

TOF has four features: severe narrowing of the right ventricular outflow (infundibular pulmonary stenosis), a large subaortic VSD, overriding of the aortic outlet above the ventricular septum and right ventricular hypertrophy (Figure 8.6). The 22q11 chromosome microdeletion is not infrequently (5–10%) associated with this anomaly. The four-chamber view may be completely normal, but an extended apical five-chamber view should demonstrate the VSD and the aortic override. The parasternal short-axis view is necessary to show the site of pulmonary stenosis.

Figure 8.6

Tetralogy of Fallot. Diagram on the left from the four-chamber view shows right ventricular hypertrophy, right ventricular outflow tract obstruction, ventricular septal defect and an overriding aorta. On the left, echocardiography from the parasternal long axis view shows an overriding aorta and ventricular septal defect. This view does not demonstrate pulmonary stenosis which can be obtained from the parasternal short axis view. RA, right atrium; LA, left atrium; RV, right ventricle; LV, left ventricle; RVOT, right ventricular outflow tract; VSD, ventricular septal defect; AO, aorta; PA, pulmonary artery.

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Tags: Fetal Medicine

Apr 14, 2017 | Posted by admin in PEDIATRICS | Comments Off

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