Hypoplastic Right Heart Syndrome (HRHS): Information on Causes, Diagnosis & Treatments
Hypoplastic right heart syndrome (HRHS) is a congenital heart problem involving the structure of the right side of the heart that is underdeveloped at birth. The issue involves the heart's muscular lower chamber that functions abnormally making it impossible or difficult for blood to pass through the lungs. Normally, the right ventricle will push blood to the heart into the body's lungs to receive oxygen before being pumped to tissue and organs.
In some cases, the newborn will also suffer an underdeveloped atrium, pulmonary artery, pulmonary valve, or tricuspid valve. These problems develop before birth in the initial stages of pregnancy. While doctors are yet to determine the exact cause of hypoplastic right heart syndrome, it is thought to develop through a combination of environmental factors and genetics. The inadequate flow of blood from the defect into the body's lungs often produces a cyanotic (blue) tinted infant.
- Who Is at Risk for Hypoplastic Right Heart Syndrome?
- Common Symptoms
- Diagnosing Hypoplastic Right Heart Syndrome
- Treating the Condition
- Prognosis (Outlook)
Who Is at Risk for Hypoplastic Right Heart Syndrome?
Mothers who previously birthed the child with hypoplastic right heart syndrome are at greater risk of birthing another baby with a similar condition. Doctors have yet to determine the exact cause of the condition but it is likely the result of environmental factors and genetics.
The main issue involving hypoplastic right heart syndrome is pulmonary valve atresia where the child is born without the pulmonary valve that is essential in the opening and closing the heart chamber to allow the flow of blood to enter the pulmonary artery. However, there also secondary issues associated with HRHS that include:
- Hypoplastic (small) Right Ventricle – Normally developed lower chamber of the heart pumps blood to the lungs
- Hypoplastic (small) Tricuspid Valve – The small bowel restricts the flow of blood into the right ventricle
- Hypoplastic (small) Pulmonary Artery
- The flow of blood from the heart to the coronary arteries can be restricted and cause considerable damage to the heart muscle
Without treatment, the condition can be fatal.
The most common symptoms associated with hypoplastic right heart syndrome involve:
- Cyanosis where the baby's skin and fingernails appear blue due to a lack of oxygen
- Poor feeding habits
- Rapid breath process
- Difficulty in breathing
- Slow growth
- Poor weight gain
- Circulatory collapse that might involve cold skin, gray appearance, or the heart to stop beating
Typically, and an inadequate amount of blood supply entering the lungs often results in insufficiently oxygenated blood delivered throughout the body. In addition, the heart a positive ventricle can exhaust easily would feeding, moving, or even breathing.
Birthing a Baby with Hypoplastic Right Heart Syndrome
Most babies identified with hypoplastic right heart syndrome can be delivered through the vaginal canal unless other modes a delivery are recommended. However, the child should be birthed that a center that specializes in birthing and staffed with neonatologists and pediatric cardiologists. The facility should also have a NICU (neonatal intensive care unit).
Once the child is born the doctor will need to prescribe intravenous dosages of PGE (prostaglandin) to ensure that the baby's patent ductus arteriosus (PDA) remains open. The PDA was essential while the child is in the womb and can serve as a temporary solution for ensuring that the lungs receive adequate blood flow.
In the first few days of the baby's life, the doctor may choose to perform a balloon atrial septectomy using cardiac catheterization procedures or a thin flexible catheter (tube) is guided through the umbilical vein inside the umbilical cord to create a large opening between the heart's top chambers.
Diagnosing Hypoplastic Right Heart Syndrome
Oftentimes, hypoplastic right heart syndrome is diagnosed by the obstetrician or pediatrician performing a physical examination just after the child is born. Using a stethoscope, a detectable heart murmur may be identified that can help the pediatric cardiologist accurately diagnose the condition. The murmur usually presents itself as a noise associated with turbulent blood flow as it passes through the tiny opening.
In addition, the doctor may choose to order an echocardiogram that can produce visual imagery of the function and structure of the heart. This machine uses sound waves and an electronic sensor that records the information is the blood moves through the heart and heart valves.
In some cases, the condition is detected early using prenatal ultrasound equipment when the fetus is in the womb. Unfortunately, an echocardiogram on the fetus is rarely performed even though this test is minimally invasive compared other procedures like amniocentesis for amniotic fluid is withdrawn from the mother's womb using along for needle.
Treating the Condition
The doctor typically has three options for treating hypoplastic right heart syndrome that include open heart surgery, a heart transplant, or the Norwood procedure. This procedure is performed in three distinct stages to create a functional circulatory system.
If the Norwood procedure is performed on children before the age of five, they have a 70% chance of normal growth and development. The initial procedure is performed just after the child's birth. Within six months, a shunt is added to the child's pulmonary arteries. This is followed by the Fontan operation that occurs within the first three years of the child's life. This procedure creates a channel through the outside of the heart to allow the oxygenated blood to flow passively from the heart to the lungs.
The post-repair prognosis (survival rate) of a child who has undergone a Fontan procedure increases life longevity between 15 and 30 years. However, this outcome in no way meets the child will not succumb to the condition, but only that the child's deteriorating heart function often means they will be listed for heart transplant.
In many cases, the parents will immediately opt in for a heart transplant after the child has been born instead of following normal treatment involving a Fontan procedure. Alternatively, some parents believe that medical advancements involving heart transplantation has yet to reach the level of surety of the child's longevity and instead will choose the Fontan procedure to buy time.
That said, the child's outlook for living a healthy life after being born with hypoplastic right heart syndrome has never been better. The condition was once considered to produce fatal certainty. However, in recent years, many children are now surviving the three stages of repair and go on to live active lives.
There are certain aspects of suffering from the congenital heart disease that requires specific care tips to avoid a heart infection that can easily develop without an apparent reason. Parents should consider following specific care tips of their child that include:
- Dental Care – Any individual suffering from any form of heart disease has an increased potential risk of developing a heart infection. This is especially true when undergoing dental care where germs in the mouth can easily spread into the body's bloodstream and eventually cause an infection in the heart.
- Exercise – Children of undergone a shunt operation are usually limited to light exercise.
- Vaccination Scheduling – Children who have had a heart transplantation usually follow a variable vaccination schedule that is much different than children who have not had a heart transplant.
Before the doctor prescribes any medications, they should be fully aware of the child's congenital heart defect and any repairs that have been made to minimize the potential for serious side effects or unusual symptoms caused by taking much-needed drugs.