Pulmonary hypertension (PH) literally means high blood pressure (“hypertension”) in the lungs (“pulmonary”). Pulmonary hypertension is a disease of the very small blood vessels within the lungs. When they become narrowed, scarred or clotted, it is more difficult for blood to pass through the vessels. The right side of the heart then has to work harder to pump blood through these vessels. Therefore, pulmonary hypertension affects not only the lungs but the heart as well.

There are many different reasons why pulmonary hypertension develops. Some of the most common causes in children are:

• Premature birth
• Prolonged mechanical ventilation
• Certain types of heart disease
• Diaphragmatic hernia
• Sickle cell disease
• HIV
• Portal hypertension
• Drug or toxin ingestion
• Familial
• Idiopathic (no known cause)

The incidence of pediatric pulmonary hypertension is difficult to assess because there are various types. It is, overall, a rather rare disease, but is seen in people of all ages and all ethnic backgrounds. Idiopathic pulmonary hypertension (PH with an unknown cause) is diagnosed in about two out of every one million people each year. Secondary pulmonary hypertension (PH with a known cause) is more common.

What Are the Symptoms of Pulmonary Hypertension?

The signs and symptoms of pulmonary hypertension vary. Depending on the age of the patient and the cause of pulmonary hypertension, it is frequently misdiagnosed in older children or adults. Often, patients are diagnosed with asthma or other lung problems, and PH is not considered because it is so rare. Symptoms in adults and older pediatric patients are shortness of breath, fatigue, lightheadedness, fainting or chest pain.

In babies with congenital heart disease, babies who are on a ventilator or babies born with a diaphragmatic hernia, PH is more likely to be considered. The major symptoms are problems breathing or a “large heart” on chest x-ray. An echocardiogram (ultrasound of the heart) may also show a large right side of the heart which is caused by its having to work extra hard to pump.

How Is Pulmonary Hypertension Diagnosed?

As mentioned above, pulmonary hypertension is not always easily diagnosed. However, when a person is having some of the symptoms listed above, or a baby is born with one of the problems listed above, various tests can be done to diagnose PH.

• Lab work
• Echocardiogram (echo): An ultrasound of the heart. High pressure on the right side of the heart may indicate PH.
• Electrocardiogram (ECG): A recording of the heart's electric current.
• Six-minute walk test: For older children, to assess their exercise ability.
• Right heart catheterization: A direct measurement of pressure in the heart. Gives doctors an idea of how well the heart is pumping.

How Is Pulmonary Hypertension Treated?

There are various methods of treating pulmonary hypertension and your child's physicians will decide what is best in his or her specific case. Some of these treatments may include:

• Oxygen therapy
• Anticoagulants (“blood thinners”)
• Diuretics

Medications to help relax the blood vessels in the lungs, decreasing the blood pressure in the lungs. These can include:

• Inhaled medicines, such as nitric oxide and iloprost
• Oral medications, which may include calcium channel blockers, sildenafil or bosentan
• Intravenous medications, such as epoprostenol and treprostinil

Outcomes

There is no effective way of preventing pulmonary hypertension from occurring. If it progresses without management and treatment, it can cause worsening problems both in the lungs and in the heart. If treated early enough in children, in many cases it is manageable. New treatments have become available recently, which are significantly improving outcomes in patients with PH.