Pulmonary Hypertension and Congenital Heart Disease

What is pulmonary hypertension?

Pulmonary arteries carry blood from the heart to the lungs. In the lungs, the blood picks up oxygen. Pulmonary hypertension (PH) happens when pressure is abnormally high in the blood vessels of the lungs. Pulmonary arterial hypertension (PAH) is one type of PH.

Depending on the type of PH, blood vessels in the lungs may narrow, become stiff or undergo changes that make it hard for blood to flow through them. Like a kink in a garden hose, increased resistance to blood flow causes pressure builds up and makes the right side of the heart to work harder. Over time, the right side of the heart may weaken and have difficulty pumping enough blood through the lungs. As a result, people may feel tired, dizzy or short of breath.

What causes pulmonary hypertension in people with congenital heart disease (CHD)?

Some congenital heart defects can increase the risk of developing PH. In some people with CHD, pulmonary vascular disease can develop even after the heart defect has been repaired and may have features like pulmonary arterial hypertension.

Some CHDs, such as ventricular septal defects and atrial septal defects, can increase blood flow to the lungs. Over time, this extra blood flow can cause changes in the small blood vessels of the lungs, potentially leading to pulmonary arterial hypertension.

How is pulmonary hypertension treated?

When appropriate, CHDs should be repaired before irreversible pulmonary vascular disease develops. However, PH can persist, recur or develop after repair of some congenital heart defects. Some medications may help manage PH related to CHD. Certain heart valve conditions, such as mitral stenosis (narrowing of the mitral valve), can also increase pressure in the blood vessels of the lungs and lead to PH. Treating the underlying valve condition may lower pulmonary pressures, although PH may not completely resolve.

People with PH often need ongoing medical care. Regular follow-up with healthcare professionals experienced in treating pulmonary hypertension is important. People with CHD-related PH may also benefit from care at a center with expertise in both congenital, heart disease and pulmonary hypertension.

When an underlying condition causes PH, treating that condition is an important first step. However, PH may persist even after the underlying condition is treated, particularly when changes in the blood vessels of the lungs have become established.

Although PH is a serious condition, treatment depends on its cause, severity and type. Treatment may include:

• Oxygen therapy
• Medications
• Diuretics (water pills)
• Anticoagulants
• Medications that lower pressure in the lung arteries and help prevent more damage to the blood vessels in the lungs

In some cases, a lung transplant may be considered. For people with CHD and severe, irreversible PH, a combined heart-lung transplant may be needed.

How does pulmonary hypertension affect children with CHD?

Repairing certain congenital heart defects may reduce pulmonary pressures and, in some children, allow pulmonary pressures to return to normal. In some children, however, pulmonary pressures remain elevated after repair, increasing the workload on the right side of the heart. In some children with severe, irreversible pulmonary vascular disease, repairing the heart defect may be too risky or no longer be beneficial.

After surgery, oxygen or medications may be used to try to relax the blood vessels in the lungs and lower blood pressure. These treatments may also be considered for selected children who cannot undergo repair.

How are cyanosis and pulmonary hypertension connected?

Cyanosis is a bluish or grayish discoloration of the skin, lips or nails that can occur when the blood has a lower-than-normal oxygen level.

Some CHDs create abnormal connections between the heart chambers or major blood vessels. These connections can allow oxygen-poor blood to bypass the lungs and enter the body’s circulation. Over time, increased blood flow and pressure in the lungs can lead to pulmonary hypertension. If this damage becomes severe, blood flow through the abnormal connection may reverse direction, allowing even more oxygen-poor blood to enter the body.

To adapt to chronically low oxygen levels, the body may produce extra red blood cells. This increase in red blood cells is called secondary erythrocytosis. Severe secondary erythrocytosis can sometimes cause symptoms such as:

• Headaches
• Fatigue
• Reduced exercise tolerance

Therapeutic phlebotomy may be considered in selected people with significant symptoms of hyperviscosity after other causes of symptoms, including iron deficiency, have been evaluated.

Phlebotomy in people with cyanotic CHD should be managed in consultation with clinicians experienced in congenital heart disease and its complications.

Can people with pulmonary hypertension be physically active?

Many people with PH can live active, fulfilling lives. However, it’s important to take precautions. Ask your healthcare team which types and levels of physical activity are appropriate for you.

PH is a lifelong condition. Smoking and exposure to low-oxygen environments, including high altitude, may worsen symptoms or place additional stress on the heart and lungs.

Be as active as your doctor recommends. Strenuous exercise or activities involving heavy lifting or straining, may not be appropriate for some people with PH because they can place additional stress on the heart and circulation. Some people may develop symptoms such as chest pain, dizziness or severe shortness of breath during exertion. Light to moderate physical activity is often safe but talk with your doctor if exercise makes you feel unwell.

Some people with PH may benefit from a supervised exercise or rehabilitation program designed for their individual needs. These programs have healthcare professionals who monitor you while you exercise.

Many people with PH have days when they feel better and days when they feel worse. Listen to your body and rest when needed.

Which medications help with pulmonary hypertension?

People with PH should review all prescription and over-the-counter medications with their healthcare team because some medicines can affect blood pressure, fluid balance, or heart and lung function. Talk with your healthcare team about any medications you take, including cold and decongestant medications.

Why is pregnancy risky for people with pulmonary hypertension?

Pregnancy carries a high risk of serious complications for people with pulmonary arterial hypertension and some other forms of severe PH and require pre-pregnancy counseling by a specialized healthcare team. Pregnancy and the period around delivery cause major changes in the blood volume and cardiovascular function that can place substantial strain on the heart and lungs in people with significant PH.

Some types of birth control may be safer than others for people with PH. Some estrogen-containing contraceptives may not be appropriate for people with PAH or other forms of PH because they can increase the risk of blood clots. Progestin-only or other highly effective contraceptive options may be appropriate, depending on a person’s medical condition and preferences. Talk with your healthcare team about which birth control method is right for you.

Learn more in our section on Birth Control and Pregnancy.

Which precautions should people with pulmonary hypertension take?

Air travel

Some forms of CHD associated with can lower the amount of oxygen in the blood. Many people with PH can travel by air, but the need for additional evaluation or supplemental oxygen, depends on their oxygen levels, symptoms, and overall condition. Your healthcare team may recommend it if it improves your oxygen levels.

During long periods of travel, stay hydrated and move around periodically when it is safe to do so. Long periods of inactivity can increase the risk of blood clots. Ask your healthcare team whether compression socks are appropriate for you.

High altitude or low-oxygen environments

People with PH should discuss travel to high-altitude or other low-oxygen environments with their healthcare team.

Vaccines

Talk with your healthcare team about which vaccines are recommended for you based on current guidelines or your health needs. These may include:

• Seasonal flu vaccine
• COVID-19 vaccine
• Age-appropriate pneumococcal vaccine

Respiratory infections can place additional stress on the heart and lungs and may be especially serious for people with significant PH.

Following your treatment plan

Do not stop taking prescribed medications unless your PH specialist recommends it. Treatment can improve symptoms and help manage many forms of PH. Whether PH improves or resolves depends on its underlying cause. 

Preventing endocarditis

People with PH and certain CHDs may need antibiotics before certain dental procedures to help prevent endocarditis. Talk with your healthcare team about what’s right for you.

Learn more about pulmonary hypertension

For more information about PH, visit the Pulmonary Hypertension Association.