Treatment Options for Newborn Heart Defects

Newborn heart defects

Newborn heart defects, also known as congenital heart diseases (CHD), are structural abnormalities of the heart or blood vessels present at birth.¹ CHD is one of the most common types of birth defects and the leading cause of mortality in children.

Blood vessels have a responsibility of carrying blood, nutrients and oxygen throughout the body; irregularities in their structure or function may impair blood flow and impact a person’s health.

Several types of neonatal cardiac abnormalities exist, and the treatment depends on which defect(s) a person has. The most common abnormalities involve any of the following:²

• Heart valves
• Blood vessels
• Heart chambers

Some congenital heart defects are classified as ‘simple’ and do not require treatment, whereas others are considered ‘complex’ and require close monitoring of the individual, as well as a combination of various treatment strategies.²

The anatomy of the heart and an overview of cardiac circulation

To understand the reasons for neonatal heart disorders, it is first crucial to garner an appreciation and understanding of the basics of cardiac circulation.

The human heart is composed of four chambers: two atria (left and right) and two ventricles (left and right). Oxygen-deprived (i.e., deoxygenated) blood from the body enters the heart through two large veins known as the superior and inferior vena cava and fills the right atrium. The blood then passes into the right ventricle through a valve that separates these two right chambers, called the tricuspid valve.³

From the right ventricle, blood is sent to the lungs through the pulmonary artery via the pulmonary valve, where it becomes oxygen-rich (i.e., oxygenated). The oxygen-rich blood returns to the heart through the pulmonary veins and enters the left atrium before it passes into the left ventricle through the mitral valve that separates these two left chambers.

The pressure in the left ventricle is greater than that of the other three chambers, which is required to pump blood out of the heart via the aorta through the aortic valve and be sent around the body.³

The basic anatomy of the human heart is depicted below.

Overview of ‘simple’ and ‘complex’ newborn heart defects

Simple heart defects

• Atrial/Ventricular septal defects (ASD/VSD)
• Patent ductus arteriosus (PDA)
• Coarctation of the aorta
• Pulmonary/Aortic valve stenosis

Complex heart defects

• Tetralogy of fallot
• D-transposition of the great arteries
• Ebstein’s anomaly
• Truncus arteriosus
• Total anomalous pulmonary venous connection (TAPVC)
• Single ventricle defects

Different types of newborn heart defects

Atrial/Ventricular septal defects (ASD/VSD)

Atrial and ventricular septal defects (ASD and VSD, respectively) are congenital heart defects characterised by the presence of a hole in the wall (i.e., septum) between the two upper or lower chambers (i.e., the left/right atria and ventricles, respectively) of the heart.⁴

Deoxygenated blood from the right atrium/ventricle mixes with oxygenated blood in the left atrium/ventricle through the hole between them.

Small septal defects are considered ‘simple’ and close naturally in childhood as the heart develops.⁴ However, larger septal defects may require close monitoring and surgical intervention to prevent further complications such as pulmonary hypertension or stroke.⁴

Patent ductus arteriosus (PDA)

Patent ductus arteriosus (PDA) is considered a simple congenital heart defect, where the space between two of the body’s largest arteries (i.e., the aorta and the pulmonary artery), do not close properly after birth². This leaves an opening where oxygenated blood from the aorta can readily mix with the deoxygenated blood carried by the pulmonary artery.

Coarctation of the aorta

Coarctation of the aorta is characterised by the narrowing of the aorta. Complications include increased blood pressure in the upper body, known as hypertension.⁷

Pulmonary/Aortic valve stenosis

Pulmonary valve stenosis is a congenital heart defect that causes the pulmonary valve to become narrow or stiff, which disrupts the normal flow of blood from the heart to the lungs through the pulmonary artery.²

Aortic valve stenosis is a similar congenital heart defect which affects the aortic valve, located between the left ventricle and the aorta.

Tetralogy of Fallot

Tetralogy of Fallot is considered a complex congenital heart disorder that involves a combination of several heart defects, such as stenosis of the pulmonary valve, misplaced aorta (i.e., the aorta is between the two ventricles instead of above the left ventricle), ventricular septal defect, and the abnormal thickening of the right ventricular wall due to it having to work harder (i.e., right ventricular hypertrophy).²

D-transposition of the great arteries

D-transposition of the great arteries is a rare congenital heart defect where the main arteries of the heart are misplaced: the aorta (required for the transportation of oxygen-rich blood throughout the body) arises from the right ventricle rather than the left ventricle, and the pulmonary artery (which is needed for the transportation of oxygen-deprived blood to the lungs to become oxygenated) is present in the left ventricle.⁸

This type of heart is considered incompatible with life.

Ebstein’s anomaly

Ebstein’s anomaly is a rare (incidence of <1%) congenital heart defect in which the valve separating the right atrium and right ventricle, called the tricuspid valve, does not form properly, and thus causes the backward flow of blood.⁹

Truncus arteriosus

Truncus arteriosus is a rare congenital disorder characterised by an abnormality in the major arteries of the heart. In a normal heart, the aorta extends from the left ventricle and the pulmonary artery arises from the right ventricle. In truncus arteriosus, however, only one large blood vessel carries blood out of the heart. This means that oxygen-rich blood (from the aorta) and oxygen-deprived blood (from the pulmonary artery) mix in the large blood vessel, where it is then sent to the lungs and the body.

Total anomalous pulmonary venous connection (TAPVC)

Total anomalous pulmonary venous connection (TAPVC) is characterised by a defect in the veins that carries blood back to the heart from the lungs. Oxygenated blood from the lungs does not reenter the heart through the normal route (which is through the left atrium), but instead, fills into the right atrium.¹⁰

Single ventricle defects

A single ventricle defect occurs when an individual is born with one ventricle instead of two. This condition is characterised by the anatomical loss of the ventricular cavity which is required for the creation of two distinct ventricles.¹¹

Treatment option for the different types of newborn heart defects

Atrial/Ventricular septal defects (ASD/VSD)

ASD or VSD that is smaller than 5 mm in size usually closes spontaneously. However, a defect that remains open might become problematic later in life, and hence, would require surgical intervention.⁵ The most common surgical strategy for ASD/VSD is a procedure known as ‘percutaneous transcatheter closure’, which involves inserting a thin tube called a catheter into a vein in the thigh until it reaches the heart. A closure device attached to one end of the catheter covers the hole on both sides, stimulating tissue growth over the hole.⁶

Patent ductus arteriosus (PDA)

PDA often closes up on its own but medication such as indomethacin, or a special form of ibuprofen can stimulate the closure of the hole.² Cardiac catheterisation or surgery may also be recommended to close the opening if the medications are ineffective. Open heart surgery is another treatment option that involves tying the duct shut to close it.

Coarctation of the aorta

Surgery is recommended in the first few days of the newborn’s life to restore normal blood flow in the aorta. A common technique involves removing the narrowed section of the aorta and joining the two remaining ends. Another option is the insertion of a stent (i.e., a tube-like device) into the affected area to widen it.

Pulmonary/Aortic valve stenosis

Most newborns and young children do not require treatment for this congenital heart abnormality. However, those who do require medical intervention for their pulmonary stenosis undergo a procedure known as balloon valvuloplasty, where a catheter is passed through the blood vessels to the site of the narrowed valve. The balloon attached to the catheter is inflated, enabling the valve to be stretched, ultimately relieving the blockage of blood flow.

The treatment strategy for aortic valve stenosis is similar to pulmonary valve stenosis. However, if this method fails, open heart surgery may be recommended to replace the leaky valve.

If balloon valvuloplasty is ineffective, the newborn may need to get their valve opened (valvotomy), or replaced through open heart surgery.

Tetralogy of Fallot

Surgery is the recommended treatment option for newborns with a severe form of this complex heart condition. However, if symptoms are less severe, then surgery will be carried out when the newborn reaches around 5 months of age.

D-transposition of the great arteries

Shortly after birth, the newborn is prescribed a medication called prostaglandin, which helps stop the passage between the aorta and the pulmonary arteries from closing.² Oxygen-rich and oxygen-deprived blood will mix, thereby allowing alleviation of some of the newborn’s symptoms.

A catheter may be used to create a temporary hole between the two upper chambers of the heart, enabling the blood to mix. Alternatively, a procedure known as ‘atrial switch’ is carried out to remove the transposed arteries and reattach them in the correct position.²

Ebstein’s anomaly

Ebstein’s anomaly is often not severe and does not require treatment. However, some people may need medications to control cardiac factors such as their heart rate.

Surgery might be advised to repair the faulty tricuspid valve, but if this turns out to be ineffective, then a valve transplant is usually recommended.²

Truncus arteriosus

Surgery is the common treatment method for this congenital heart defect.² The newborn is provided with medication to induce them into a stable state. A surgeon then separates the large abnormal blood vessel to create two distinct blood vessels that carry oxygenated and deoxygenated blood to the body and the lungs separately.²

Total anomalous pulmonary venous connection (TAPVC)

The recommended action for patients with TAPVC is surgery. An excision is made in the upper heart chambers, allowing blood to be drained into the left atrium from the pulmonary veins instead of being emptied into the right atrium.¹⁰

Single ventricle defects

The treatment for single ventricle defects often involves a complex, multistage surgical procedure that is carried out at different points of a newborn’s life. The surgeon creates artificial passages to encourage blood flow to the lungs, where it can become oxygenated.²

Summary

Newborn heart defects are characterised by structural abnormalities in the heart or blood vessels, and are one of the most common causes of death amongst infants. There are several types of newborn heart defects, ranging from abnormalities in the chambers of the heart that receive blood (i.e., atria) or pump blood out of the heart (i.e., ventricles) or the blood vessels of the heart.

Each heart defect has its own recommended treatment strategy, aiming to alleviate abnormal blood pressure in the affected newborn and ultimately provide a better quality of life. Treatment options include medications and surgical procedures to repair holes in the heart walls, relocate misjoined blood vessels or transplantation of the heart.