Pulmonary Hypertension

Types of pulmonary hypertension

To understand the types of pulmonary hypertension, it may be helpful to review the basic functions of the heart's two sides: The right side pumps blood to the lungs to pick up oxygen. The left side pumps oxygen-rich blood out to the entire body.

Pulmonary hypertension is classified into five groups:

• Pulmonary arterial hypertension (PAH). This is when the blood pressure increase is due to narrowing, stiffening or thickening of the small arteries that circulate blood from the heart through the lungs to pick up oxygen. As a result of these changes, the heart has to work harder than normal to pump enough blood to the lungs to meet the body's needs.
• Pulmonary hypertension due to left heart disease. Problems occurring on the heart's left side, such as certain types of heart failure or mitral valve disorders, make the heart unable to keep up with the blood returning from the lungs. This backup raises pulmonary blood pressure.
• Pulmonary hypertension due to lung disease. An underlying respiratory condition can lead to elevated blood pressure in the lungs. Conditions that may do this include interstitial lung disease, emphysema, asthmatic bronchitis, sleep apnea and long-term exposure to high altitudes.
• Pulmonary hypertension due to chronic blood clots. Scar tissue caused by blood clots can narrow blood vessels in the lungs, blocking normal flow and forcing the heart's right side to work harder.
• Pulmonary hypertension due to unknown causes. For some patients, their pulmonary hypertension is related to other diseases in ways that aren't well understood. Possible associated conditions include sarcoidosis, sickle cell anemia, chronic hemolytic anemia, certain metabolic disorders and having undergone a splenectomy (spleen removal).

Symptoms of pulmonary hypertension

In the early stages of pulmonary hypertension, symptoms tend to be nonspecific and similar to those that occur in many other conditions, with people experiencing shortness of breath, fatigue and chest pain. Other symptoms can include:

• Dizziness
• Swollen ankles and legs
• Fainting
• A bluish cast to lips and skin

Diagnosis of pulmonary hypertension

In early stages, pulmonary hypertension is difficult to detect during a routine physical exam. It may be two to three years before symptoms become severe enough to be noticed. Pulmonary hypertension is diagnosed primarily with an echocardiogram (ECG), an ultrasound exam of the heart. Images generated by sound waves reflecting off the heart's structures make it possible to measure the heart's size and shape and estimate the pulmonary artery pressure.

Additional tests to diagnose pulmonary hypertension

In addition to an echocardiogram, your doctor may recommend the following tests:

• Electrocardiogram (ECG or EKG). Measures your heart's electrical function.
• Six-minute walk test. The distance you walk in six minutes is used to assess your exercise tolerance and your mobility.
• Daily living assessment. Evaluates how well you accomplish routine tasks of everyday life.

You may also have a Swan-Ganz or right heart catheterization, which can be used to confirm a diagnosis and obtain information that guides therapy decisions. This procedure uses a specially designed catheter (thin, flexible tube) to reach the heart's right side and the pulmonary artery. The test measures blood pressure inside the heart and blood vessels of the lungs as well as blood flow.

If your doctor determines that you have pulmonary hypertension, the next step will be to learn what’s causing it. Tests to reveal the cause include:

• Computed tomography (CT) scan. Also called a CAT scan, the results can show whether there's a blood clot or certain other problems in your lungs.
• Pulmonary function tests. These tests measure aspects of your breathing and indicate how well your lungs are working. The results can rule out obstructive lung disease.
• Overnight sleep study. By measuring sleep cycles and stages, this combination of procedures reveals whether you have sleep apnea, a condition in which you briefly and repeatedly stop breathing while asleep.
• Lab tests. Certain tests, usually using a blood sample, can rule out hepatitis, collagen diseases, HIV and other conditions that can elevate blood pressure in the lungs.

When doctors can't find an underlying cause, the diagnosis is primary pulmonary hypertension.

Classification of pulmonary hypertension

The New York Heart Association and World Health Organization identify four degrees of pulmonary hypertension:

• Class 1. No symptoms. Ordinary physical activity doesn't cause particular discomfort.
• Class 2. Symptoms occur only with activity but not at rest.
• Class 3. Even slight exertion leads to symptoms, making people limit their activity. But they are comfortable at rest.
• Class 4. Symptoms occur even at rest.

Treatment of pulmonary hypertension

If you have secondary pulmonary hypertension, treatment will generally focus on addressing the underlying cause. For instance, if a blood clot led to your hypertension, treatment may be to surgically remove the clot.

A number of treatments are used to manage primary pulmonary hypertension, though they won't cure the condition. These include:

• Calcium channel blockers. These drugs help the heart pump better by relaxing muscles in the walls of blood vessels.
• Endothelin receptor antagonists (ERAs). These drugs reverse the effects of endothelin, a substance produced in blood vessels that makes them constrict.
• Epoprostenol. This medication dilates and reverses thickening of the lungs' blood vessels and helps prevent platelets (cell fragments in blood that stop bleeding) from clotting the blood. It's infused intravenously (into a vein) using a portable pump.
• Anticoagulants. Often called blood thinners, these drugs keep blood from clotting, allowing circulating blood to flow more easily.
• Diuretics. These medications minimize water retention – which can make the heart work harder – by making the kidneys produce more urine.
• Digoxin. This drug can help the right side of the heart pump better, but patients receiving it need to be closely monitored.
• Supplemental oxygen. For patients with low blood oxygen levels, concentrated oxygen may be delivered using in-home machines and portable devices.

When all other options have failed, patients with severe pulmonary hypertension and poor quality of life may be candidates for lung transplantation or heart-lung transplantation.

Lifestyle changes for treating pulmonary hypertension

Adequate rest, a healthy diet, exercise and stress reduction can help control pulmonary hypertension. People with the disease should avoid smoking, becoming pregnant, using birth control pills and being at high altitudes.

Pulmonary hypertension treatment is often highly complex and patients require intensive ongoing follow-up. This comprehensive care is available from the specialists of the UCSF Pulmonary Hypertension Program.