Pulmonary Hypertension - Adult

Causes

PH happens when blood flow through the lungs becomes more difficult. Many things can affect blood flow, such as:

• The size of blood vessels—they can tighten and shrink the pathway for blood
• Thickened walls of blood vessels—damaged or swollen blood vessels can make it hard for blood to flow through
• Blockages in blood vessels—such as blood clots
• Lung tissue damage—can decrease the number of blood vessels
• Health problems that affect blood thickness

These changes are often the result of other illness or health issues. Sometimes it is not clear why these changes happen. PH causes can also vary by type of PH:

• Group 1 PH may not have a known cause. Known causes include:
  • Condition inherited from parents
  • Connective tissue disease
  • HIV infection
  • Congenital heart disease like septal defects
  • Drugs such as diet drugs, cocaine, and amphetamines
• Group 2 PH is caused by problems on the left side of the heart such as:
  • Chronic heart failure—the most common cause of PH
  • Tight or leaky heart valve
• Group 3 PH may be caused by lung disease or other problems that cause low oxygen levels such as:
  • COPD or idiopathic pulmonary fibrosis
  • Sleep apnea
• Group 4 PH is caused by chronic blood clots that have not gone away.
• Group 5 PH is caused by other conditions, such as:
  • Body-wide illness such as vasculitis or sarcoidosis. They can affect blood vessels and lungs.
  • Blood-related illnesses that increase thickness and flow of blood such as
    • Polycythemia or thrombocytosis
    • Sickle cell disease
  • Metabolic illness such as:
    • Thyroid disease
    • Glycogen storage disorder
  • Chronic kidney failure

Risk Factors

Things that may raise the risk of pulmonary hypertension include:

• Having one of conditions listed above
• Family history of PH
• Living at high altitude (over 10,000 feet)
• Using illicit drugs such as cocaine

Symptoms

There may be no symptoms in early PH. It may take years until any appear. Common symptoms include:

• Shortness of breath that gets worse over time
• Chronic fatigue
• Fainting spells
• Ankle swelling from fluid retention
• Chest pain

Diagnosis

The doctor will ask about symptoms and health history. A physical exam will be done. This may be enough for the doctor to suspect PH.

Tests to confirm PH may include:

• Echocardiogram
• Cardiac catheterization

Other things that can be done to look for the cause of PH are:

• Blood tests
• Measuring oxygen and carbon dioxide in the blood—this can be done with blood gas test or oximeter on finger
• Chest x-ray
• ECG
• CT scan
• Ventialtion-perfusion scan
• Pulmonary function test
• Sleep study or overnight oxygen measurements

To see how much PH has affected a person's physical activity, the doctor may order:

• A six-minute walk test
• An exercise stress test

Treatment

The goals of treatment are to:

• Diuretics—to decrease fluid buildup in body
• Blood thinning medicine—to prevent formation of new blood clots
• Oxygen therapy—to add oxygen to the blood
• Physical activity—may help with symptoms

PH that has no known cause may need more care. Treatment can help slow the progress of PH and growth of other problems. Options include:

Medicine

Medicine can help open blood vessels. This will ease pressure and help blood flow. Some medicines may also make it easier to be active and breathe. Options include:

• Calcium channel blockers
• Phosphodiesterase inhibitors
• Endothelin receptor blockers
• Prostanoids
• Stimulators of soluble guanylate cyclase
• Prostacyclin receptor antagonist

Lung Transplant

A lung transplant may be needed if other treatments do not work and PH has become severe.

Prevention

Not all PH can be prevented. Managing related conditions may help. Other steps include:

• Avoid using illicit drugs like cocaine.
• Keep a healthy weight. Weight may raise the risk of certain types of PH.
• Talk to the doctor before using weight loss medicine or supplements. Some of these may cause PH.
• Do not smoke. Smoking increases risk of lung disease such as COPD.