Many people are familiar with the term “high blood pressure,” which is also known as hypertension.
We see it repeated in advertisements, public service announcements and on the news. But there is another, less-known form of high blood pressure: pulmonary hypertension, which affects the arteries of the lungs and can lead to heart failure or other serious complications.
We asked University of Minnesota Health Cardiologist Sonia Jain, MD, to share more information about the causes, symptoms and treatments of pulmonary hypertension. Jain sees patients at Fairview Lakes Medical Center, Fairview Ridges Hospital and Fairview Southdale Hospital. She is one of three University of Minnesota Health specialists dedicated to care for pulmonary hypertension patients. Other specialists include: Cardiologist Marc Pritzker, MD, and Cardiologist Thenappan Thenappan, MD.
Pulmonary hypertension is a relatively rare type of high blood pressure that can affect the small arteries of the lungs and the right side of the heart. In one form of pulmonary hypertension, the small arteries in the lungs—called arterioles—become narrowed, blocked or destroyed. This increases pressure in the large artery of the lungs, called the pulmonary artery. The pulmonary artery carries oxygen-depleted blood from the heart’s right ventricle back to the lungs, where the blood is refreshed with oxygen. Increased pressure in the pulmonary artery forces the right ventricle to work harder to pump blood. Over time, this weakens the right side of the heart and can cause heart failure. Pulmonary hypertension is different from systemic hypertension, which is high blood pressure in the aorta.
Pulmonary hypertension can be caused by a variety of factors, and has been categorized into several groups by the World Health Organization. The groups include:
This group includes pulmonary hypertension caused by inherited genetic mutations, connective tissue diseases (such as scleroderma, lupus or rheumatoid arthritis), abnormalities of the heart present at birth (congenital heart disease), certain medications and illicit drugs, or other medical conditions such as HIV infection, liver disease and sickle cell disease. This group also includes pulmonary hypertension without a known cause, which is called idiopathic pulmonary hypertension.
Group 3 includes pulmonary hypertension that is caused by diseases of the lungs and low oxygen levels. This can include conditions such as chronic obstructive pulmonary disease (COPD), lung fibrosis and obstructive sleep apnea.
Group 4 pulmonary hypertension is caused by chronic blood clots on the lungs—also known as chronic pulmonary emboli.
Group 5 includes pulmonary hypertension that is caused by a variety of factors or conditions, including blood disorders, metabolic disorders and other causes that don’t fit into the other four groups.
Symptoms of pulmonary hypertension may include fatigue, shortness of breath, a bluish discoloration of the lips and fingers caused by low oxygen levels and swelling of the legs and abdomen. Because these symptoms can also be associated with several other conditions, pulmonary hypertension can initially be difficult to identify, Jain said. In advanced stages of the disease, patients can also experience chest pain, heart palpitations (arrhythmias) or may even pass out during exertion.
Patients who have risk factors, a family history or are suspected of having pulmonary hypertension, should seek a referral to expert heart center. To test for pulmonary hypertension, cardiologists will take a detailed history, perform a careful physical examination and order various tests. Testing includes specific blood tests, a heart ultrasound (echocardiogram) or MRI scan of the heart, lung imaging and breathing tests and a right heart catheterization.
In the last several decades, the number of treatment options has expanded due to increased pulmonary hypertension research, Jain said. Today, care providers may recommend a variety of approaches or medications. Though a cure may not be possible, care providers seek to reduce symptoms, reduce complications, improve a person’s quality of life and increase length of survival.
A number of approved medications are available for patients with Group 1 and Group 4 pulmonary hypertension. When caring for patients in the other groups, providers first attempt to treat the underlying conditions causing the pulmonary hypertension, Jain said. They may later prescribe treatment as appropriate. In advanced cases, patients may referred to receive a lung transplant.