Pulmonary hypertension is high blood pressure in the arteries leading from the heart to the lungs. Pulmonary hypertension is a different condition than ordinary high blood pressure (hypertension).
Symptoms of Pulmonary Hypertension
The main symptom of pulmonary hypertension is shortness of breath with exertion. The shortness of breath usually starts slowly and gets worse over time. Often, a person notices he or she can't perform the same activity as before without becoming winded.
Other symptoms of pulmonary hypertension can include:
- Chest pain
- Passing out suddenly
- Swelling of the legs (edema)
Causes of Pulmonary Hypertension
Many different conditions can cause pulmonary hypertension. In different ways, each of these illnesses may lead to high blood pressure in the pulmonary arteries:
- Congestive heart failure
- Venous thromboembolic disease (blood clots in the lungs)
- Human immunodeficiency virus infection
- Illegal drug use (cocaine, methamphetamine)
- Cirrhosis of the liver
- Appetite suppressant medications (fenfluramine, dexfenfluramine, diethylpropion), which are no longer available in the U.S.
- Autoimmune diseases (lupus, scleroderma, and rheumatoid arthritis)
- Heart shunts (abnormal blood flow between heart chambers)
- Chronic lung disease (emphysema, chronic bronchitis, or pulmonary fibrosis)
- Obstructive sleep apnea
When no cause can be identified after testing, the condition is called idiopathic pulmonary arterial hypertension. This condition was formerly known as primary pulmonary hypertension.
Diagnosis of Pulmonary Hypertension
Most often, a person with undiagnosed pulmonary hypertension visits the doctor for shortness of breath. The doctor then seeks the cause, gathering information through a medical history and diagnostic tests such as:
Echocardiogram: An ultrasound picture of the beating heart. An echocardiogram can estimate pulmonary artery pressures and check the function of the heart's right and left ventricles.
Computed tomography (CT scan): Detailed X-ray films of the chest provided by a CT scan may show enlarged pulmonary arteries. A CT scan may also identify other problems in the lungs that could cause shortness of breath.
Ventilation-perfusion scan (V/Q scan): A nuclear medicine test that can help identify blood clots in the lungs (pulmonary emboli), one cause of pulmonary hypertension.
Electrocardiogram (ECG or EKG): An electrical tracing of the heart's activity. ECG may show evidence of strain on the right side of the heart, a clue to the presence of pulmonary hypertension.
Chest X-ray: An X-ray can't diagnose pulmonary hypertension, but may provide helpful clues. Chest X-ray films can help identify any other contributing lung or heart conditions.
Exercise testing: A person exercises in a laboratory, while oxygen levels, heart function, or other parameters are tested for changes during exertion.
Blood tests for HIV, infections, or autoimmune diseases may contribute to the diagnosis of pulmonary hypertension.
These tests can suggest pulmonary hypertension, but to make the final diagnosis, the blood pressure in the pulmonary arteries must be measured directly. This is done through a procedure called right heart catheterization. The procedure is conducted in these steps:
- A catheter is inserted into the jugular vein in the neck, and advanced into the right side of the heart.
- A pressure monitor on the catheter records the pressures in the right ventricle of the heart and in the pulmonary arteries.
- While the catheter is in place, medicines are injected to see if the pulmonary arteries are abnormally stiff. This is called a vasoreactivity test.
Right heart catheterization is an invasive test, although it has a low risk of complications.