Pulmonary Arterial Hypertension

Background

Pulmonary Arterial Hypertension (PAH) is a condition that occurs when the pressure in the blood vessels leading from the heart to the lungs is too high. The heart pumps blood from the right side of the heart to the lungs to get oxygen. When the pressure in the pulmonary artery and the arteries in the lungs get too high, blood does not flow as well. The result is less oxygen in the blood, which leads to the symptoms of PAH.

PAH is a form of Pulmonary Hypertension(PH).There are five categories of PH groups. PAH is labeled Group 1.

Causes

PAH can occur as a result of many other diseases, such as lung disease, HIV, liver disease, heart disease, scleroderma or lupus. PAH can be inherited from your parents. It can also be a result of taking certain types of medications or illegal drugs (cocaine, methamphetamines, prescription amphetamines or diet pills).

Symptoms

Pulmonary Arterial Hypertension symptoms include:

  • Chest pain, usually in front of the chest
  • Dizziness
  • Fainting
  • Fatigue
  • Leg swelling
  • Lightheadedness during exercise
  • Shortness of breath during activity
  • Weakness

Diagnosis

There is no one way to diagnose PAH. The symptoms of PAH are similar to other heart and lung diseases. If PAH is suspected, your doctor may run a series of tests to measure blood pressure in the pulmonary arteries. The results will reveal how well the heart and lungs are working and help to rule out other conditions.

Tests include:

Chest x-ray
The x-ray views your heart and lungs. It can detect the function of the right ventricle and any lung disease that may be causing PAH.
Right heart catheterization
This procedure measures the pressure between your heart and lungs. It also shows how well your heart pumps blood to the rest of your body.
Electrocardiogram
This is a simple test to show whether the heart rhythm is irregular or steady.
Echocardiogram
Using sound waves, this test creates a picture of your heart in motion. It can estimate the pressure between your heart and lungs as well as the size and thickness of the right side of your heart.
Pulmonary function test
This test determines how well your lungs are functioning and the amount of oxygen that enters your body.

Finding the severity of Pulmonary Arterial Hypertension:

Exercise testing is used to measure the severity of PAH. The tests consist of either a six minute walk test or exercise test.

The six minute walk test measures the distance that you can quickly walk in 6 minutes. The exercise test measures how well your lungs and heart work while you exercise on a treadmill or bike. Your activity level is linked to the severity of your PAH based on a rating system from class 1 to class 4.

Class 1
No limits
Class 2
Slight or mild limits
Class 3
Noticeable limits
Class 4
Severe limits

Treatment

Specialty drug list

There is no known cure for PAH, but there are treatment options that include medications and surgery. The medication treatment goals of PAH are to decrease symptoms, improve quality of life and slow the disease progression. It is recommended that patients with PAH undergo a specific test to measure which therapy regimen will give the most benefit.

Side Effects

The drugs used to treat PAH may have several side effects and drug interactions. Inform your PAH doctor of all prescribed and OTC medications that you are taking and inform to your PAH doctor before starting any new medications.

Phosphodiesterace 5 Inhibitors (PDE5 inhibitors)
PDE5 inhibitors relax the blood vessels to promote blood flow. Common side effects include indigestion, headache and flushing. If worsening of eyesight, loss of vision, or loss of hearing occur, your doctor should be notified.
Endothelin Receptor Antagonists (ERAs)
Endothelin is a substance naturally produced in the body. In conditions like PAH, too much endothelin constricts the blood vessels and increases the pressure in the lungs. ERAs work to reduce the production of this substance. This group of medications may cause serious birth defects and should not be used if pregnant. You may need regular blood tests with Tracleer to make sure your liver is not being harmed. Other side effects include swelling, low sperm count or low red blood cell levels (anemia).
Prostacyclins
Prostacyclin is a naturally occurring substance in the body. It works to keep blood flowing freely to the lungs and absorbing oxygen more efficiently. Patients with PAH may not produce enough of this substance. These medications are given by inhalation or by continuous intravenous or subcutaneous therapy. Common side effects are headache, flushing, jaw pain, nausea or vomiting. Infused agents may cause infection or pain where the drug enters the body.
Guanylate cyclase stimulant (sGC)
This drug helps to promote improved blood flow. It may cause serious birth defects and should not be used if pregnant. You may also develop low blood pressure, headache, dizziness and swelling in your hands and feet.

Resources

Pulmonary Hypertension Association

American Thoracic Society

The National Organization for Rare Disorders

References

1. Centers for Disease Control and Prevention, Division for Heart Disease and Stroke Prevention. “Pulmonary Hypertension Fact Sheet.” http://www.cdc.gov/DHDSP/data_statistics/fact_sheets/fs_pulmonary_hypertension.htm. Accessed June 8, 2014.

2. Blurtit. “What is the Function of the Pulmonary Trunk?” http://science.blurtit.com/892607/what-is-the-function-of-the-pulmonary-trunk. Accessed June 8, 2014.

3. Pinsky, Michael R. “Pulmonary artery occlusion pressure.” http://www.ccmpitt.com/ebm/invasive_procedures/228%20Ppao%20measurement%20published.pdf. Accessed June 8, 2014.

4. Living PAH. “Causes and Classifications of PAH/LivingPAH.” http://www.livingpah.com/about-pah/causes-and-classifications/. Accessed June 8, 2014.

5. AgingCare.com. “Lung Function Tests for Breathing Problems.” http://www.agingcare.com/Articles/Lung-Function-Tests-for-Elderly-People-136557.htm. Accessed June 8, 2014.

6. Healthline. “Pulmonary Arterial Hypertension: A guide for caregivers.” http://www.healthline.com/health/pulmonary-hypertension/guide-caregivers. Accessed June 8, 2014.

7. Insights on PAH. “Treatment for PAH.” http://www.insightsonpah.com/Living_With_PAH/Treatment_for_PAH/. Accessed June 8, 2014.

8. PHA association. http://www.phassociation.org/page.aspx?pid=3565. Accessed June 8, 2014.

9. American Lung Association. http://www.lung.org/lung-disease/pulmonary-arterial-hypertension/. Accessed June 8, 2014.