Tricuspid Atresia – Symptoms and Causes
Overview
Tricuspid atresia is a rare congenital heart defect that affects how blood flows through the heart. It occurs during fetal development and is present at birth.
In this condition, the heart’s internal structure is altered in a way that disrupts normal blood circulation.
Children born with tricuspid atresia require specialized heart care and regular follow-up to support healthy growth and manage potential complications.
Signs and Symptoms
Tricuspid atresia is a heart problem that babies are born with. In this condition, the valve between the right atrium and right ventricle doesn’t form correctly. This causes blood flow problems that can lead to several noticeable symptoms.
A baby with tricuspid atresia may look blue or have bluish skin (cyanosis). This happens because their blood doesn’t get enough oxygen.
The child might also get tired quickly, especially during feeding. They may breathe faster than normal or have trouble breathing.
Some babies with this condition don’t grow as expected. They might gain weight slowly and appear smaller than other children their age.
Heart murmurs, which are unusual sounds during heartbeats, are also common. A doctor can hear these using a stethoscope.
When to Get Medical Attention
Call a doctor right away if your baby shows blue skin, especially around the lips or tongue. This is a sign that they aren’t getting enough oxygen.
Seek emergency care if your child:
- Has trouble breathing
- Breathes very fast
- Seems unusually tired
- Feeds poorly or sweats during feeding
- Faints or passes out
If your child already has a diagnosis but their symptoms get worse, contact their healthcare provider immediately.
Causes
Tricuspid atresia happens before birth when a baby’s heart doesn’t form correctly. The tricuspid valve—which should connect the right atrium and right ventricle—fails to develop, blocking normal blood flow through the heart.
How the Heart Normally Works
The heart has four chambers, with two on each side. The upper chambers are the right and left atria, while the lower chambers are the right and left ventricles.
The left ventricle is the strongest chamber as it pumps blood throughout the entire body.
Each side of the heart has a specific job. The right side sends blood to the lungs through pulmonary arteries where it picks up oxygen.
This oxygen-rich blood returns to the left side through pulmonary veins. The left side then pumps this blood through the aorta (the main artery) to supply the rest of the body.
Special doors called valves control blood flow in the heart. These valves open to let blood move forward and close to prevent backward flow.
What Happens in Tricuspid Atresia
In tricuspid atresia, the valve between the right atrium and right ventricle is missing. Instead, a solid tissue layer blocks blood from flowing between these chambers.
This means the right side cannot pump blood to the lungs as it normally would.
Blood must find another path. It moves from the right atrium directly into the left atrium through a hole in the wall between them. This hole may be either:
- An atrial septal defect (ASD)
- A patent foramen ovale (PFO)
What happens next depends on additional heart features. Some babies also have:
- A ventricular septal defect (VSD) (a hole between the lower heart chambers)
- A ductus arteriosus that remains open temporarily after birth
If a VSD is present, blood can flow from the left ventricle directly into the pulmonary artery. The amount of blood reaching the lungs depends on:
- The size of the VSD
- Whether the pulmonary valve is narrowed
If the VSD is large, too much blood may flow to the lungs, possibly causing heart failure.
Risk Factors
The most significant risk factor for tricuspid atresia is a family history of congenital heart defects. If a parent or sibling has a heart defect, the chances are higher for the baby to develop one.
Certain maternal health conditions may increase the risk. Mothers with diabetes face a higher chance of having a baby with heart problems.
Some medications taken during pregnancy can also raise the risk, including:
- Certain anti-seizure drugs
- Acne treatments with isotretinoin
- Specific blood thinners
Other risk factors include:
- Advanced maternal age (over 35), which may slightly increase the risk
- Alcohol consumption during pregnancy
- Exposure to environmental toxins or air pollution (still under study)
Complications
Tricuspid atresia can lead to several serious health problems over time. Without treatment, oxygen levels in the blood remain low, putting strain on the heart and other organs.
Heart failure is a common complication. The heart must work harder to pump blood, which can cause the heart muscle to weaken and eventually fail.
Irregular heart rhythms may develop as the heart’s electrical system becomes affected by structural changes. These arrhythmias can range from mild to life-threatening.
Growth and development problems often occur in children with tricuspid atresia. Poor oxygen delivery throughout the body can slow physical growth and, in some cases, impact brain development.
Blood clots may form due to abnormal blood flow patterns, potentially leading to a stroke if they travel to the brain.
Lung problems can develop over time. The abnormal blood flow patterns may cause high blood pressure in the lungs (pulmonary hypertension), which further strains the heart.
Liver damage is possible in long-term cases. This happens because blood backs up in the liver, causing congestion and eventually scarring.
Endocarditis risk increases in people with tricuspid atresia. This infection of the heart’s inner lining can be serious and often requires aggressive antibiotic treatment.
