Pulmonary Arterial Hypertension (PAH), formerly referred to as Primary Pulmonary Hypertension (PPH), is characterized by continuous high blood pressure in the pulmonary artery. For example, the average blood pressure in a normal pulmonary artery is about 14 mmHg when a person is resting. In PAH, the average is usually greater than 25 mmHg.
PAH is a serious condition for which there are treatments, but unfortunately no cure. Treatments, however, continue to improve dramatically, and numerous patients have been able to live normal lives.
Changes to the body: The pulmonary arteries are the blood vessels that carry oxygen-poor blood from the right ventricle in the heart to the small arteries in the lungs. In PAH, three types of changes may occur in the pulmonary arteries:
- The muscles within the walls of the arteries may tighten up. This makes the inside of the arteries narrower.
- The walls of the pulmonary arteries may thicken as the amount of muscle increases in some arteries. Scar tissue may form in the walls of arteries. As the walls thicken and scar, the arteries become increasingly narrow.
- Tiny blood clots may form within the smaller arteries, causing blockages.
As a result of these changes there is less room for the blood to flow through these narrower arteries, which may cause them to stiffen and possibly become completely blocked.
The narrowing of the pulmonary arteries also causes the right side of heart to work harder to pump blood through the lungs. Over time, the heart muscle weakens to such an extent that the heart loses its ability to pump enough blood through the body. This is called right heart failure. Heart failure is the most common cause of death in people with PAH.
PAH Subgroups:
In 2007, however, doctors associated with the World Health Organization agreed to replace the term Promary Pulmonary Hypertension in favor of Pulmonary Arterial Hypertension. This organization created the following three subgroups:
- Idiopathic PAH - cause of the disease is unknown
- Familial PAH - disease is inherited
- Associated with PAH - disease is caused by other conditions or toxins (such as diet drugs, pulmonary embolism, etc.)
Number of Cases:
Approximately 800-1000 new cases of Primary Pulmonary Arterial Hypertension are diagnosed in the United States each year. Secondary Pulmonary Arterial Hypertension, however, is much more common.
Improvements in Treatment:In the last few years, knowledge of PAH in the medical community has increased significantly, and more treatment options are now available. In addition, research is continuing into many promising therapies that should lead to the extension and improvement of the lives of people living with PAH
Other Names for Pulmonary Arterial Hypertension
- PPH (Primary pulmonary hypertension)
- Idiopathic pulmonary arterial hypertension
- Sporadic primary pulmonary hypertension
- Familial primary pulmonary hypertension
- Secondary pulmonary arterial hypertension
- Pulmonary hypertension