Hypoplastic Right Heart Syndrome (HRHS)

How is HRHS Diagnosed?

Hypoplastic right heart may first be suspected when a routine prenatal ultrasound shows an irregularity in the fetal heart. Your health care provider may order a fetal echocardiogram (fetal echo) to confirm the diagnosis so that special preparations can be made for the baby’s delivery and care after birth.   

What Causes HRHS?  

The cause of hypoplastic right heart syndrome is not fully understood, but it is believed to result from a combination of genetic and environmental factors during fetal development. The defect likely occurs early in pregnancy, when the baby’s heart is developing. Genetic and/or environmental factors may contribute to the development of this condition and your team may recommend genetic testing as part of the baby’s evaluation.  

While HRHS may be associated with certain genetic syndromes, it can also manifest in a child with no family history of congenital heart abnormalities. 

What Are the Signs and Symptoms of HRHS? 

Hypoplastic right heart syndrome appears very early in newborn babies, from the first few days to weeks of life. Symptoms may include: 

• A bluish color to the skin and lips (cyanosis) due to low blood oxygen 
• Failure to gain weight and grow 
• Pale skin 
• Poor feeding because of tiring easily 
• Sweating 
• Swollen legs or abdomen 
• Trouble breathing

How is HRHS Treated?

If the diagnosis of HRHS is made before birth, you will meet regularly with your healthcare team at Lurie Children’s throughout the pregnancy to plan for your baby’s arrival and care. A comprehensive fetal care consultation will be arranged with specialists who will be involved in your child’s treatment.

Babies born with HRHS usually require a series of surgeries during the first few years of life to re-route the blood flow through their heart. Children with these heart defects require lifelong cardiac care to ensure they have every opportunity to lead healthy lives as they grow. The specific procedures and timing will depend on your child’s condition and any other heart defects they may have. The series of surgeries HRHS usually requires include:

Neonatal Procedure  

Within the first few days to weeks of your baby’s life, your baby may need a procedure to help balance the blood flow to the lungs and the body. This procedure could be done in the cardiac catheterization lab or might require an operation. In some cases, the blood flow is already naturally balanced, and your baby might eventually be able to go home without an operation to wait for the next surgery.

Glenn Procedure

A pediatric cardiologist will decide the timing of this second surgery, which is usually done when your baby is 4 to 6 months old. The procedure directs the oxygen-poor blood from the upper body to flow directly to their pulmonary arteries, so blood can collect oxygen from the baby’s lungs without going through their heart.   

Fontan Procedure

The third surgery is performed when your child is 2 to 3 years old. The Fontan procedure is done to complete the separation of systemic and pulmonary blood circulation, allowing the oxygen-poor blood from the upper and lower body to flow directly to the lungs without passing through the heart. After the procedure, your child’s oxygen levels will be similar to a child with a typical heart. Although the surgery does not create normal circulation in your child’s body, it does improve blood flow enough for them to live and grow for many years.  
 
Many children with HRHS need future operations or cardiac catheter-based procedures, complex testing, multiple hospitalizations and frequent outpatient follow-up. In the most severe cases of HRHS, children may need a heart transplant.  
 
The Lurie Children’s Single Ventricle Team is uniquely equipped to help these patients and their families face these challenges both inside and outside the hospital. Learn more from Lurie Children’s Single Ventricle Roadmap.

What is the Long-term Outlook for HRHS?

The long-term outlook for children with HRHS depends on the severity of their condition, the presence of other associated defects and their response to treatment.

The long-term outlook for children with HRHS has improved significantly in the past few decades. Many babies with the condition live to adulthood. Still, these babies are especially fragile between their first and second surgeries which is why they are followed by a specialized team that coordinates their care. Even after the second surgery, they are at risk for serious health problems from common childhood illnesses such as colds. They may have trouble feeding and growing.  

After their surgeries, children with HRHS will require regular follow-ups. They may face complications and need to limit their physical activities.

Complications may include:

• Thickening of the nail beds on fingers and toes (clubbing)
• Frequent pneumonia
• Heart rhythm problems
• Heart failure

Children with single ventricle physiology such as HRHS are also at increased risk for challenges with their development, social functioning and school performance that need to be watched carefully throughout their lives. Lurie Children’s NICU-Cardiac Neurodevelopmental Program works with families to ensure that all of our cardiac patients are achieving their full potential.

With advances in medical and surgical management, many children with hypoplastic right heart can lead relatively normal lives. However, they will need lifelong care with a cardiologist to monitor heart function, manage potential complications and adjust treatment as needed. As they approach adulthood, our team will help them transition to an adult cardiologist with special expertise in congenital heart disease through Lurie Children’s Adult Congenital Heart Disease (ACHD) Program.