Definition

Pulmonary arterial blood pressure is the force the right side of the heart needs to overcome to push blood to the lungs. Pulmonary hypertension (PH) is a higher pressure than normal. It will make it harder for the right side of the heart to pump blood.

If PH is left untreated it can lead to heart failure. The right side of the heart will no longer be able to pump enough blood. There are 5 different groups of PH.

Pulmonary Circulation

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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 inflamed 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 fail to resolve.
• Group 5 PH is caused by other conditions. Examples include:
  • 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 renal failure

Risk Factors

Factors that may increase your chance of pulmonary hypertension include:

• Having one of conditions listed above
• Family history of PH
• Home at high altitude (over 10,000 feet)
• Use of street 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 continues to get worse over time
• Chronic fatigue
• Fainting spells
• Ankle swelling from fluid retention
• Chest pain

Diagnosis

Your doctor will ask about your symptoms and past health. You may also be asked about your family’s health history. A physical exam will be done. The doctor may suspect PH based on your symptoms and exam.

Tests to confirm PH may include:

• Echocardiogram
• Cardiac catheterization

To look for the cause of PH, your doctor may also do 1 or more of the following:

• Blood tests
• Measure of oxygen and carbon dioxide in the blood—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 your physical activity, you doctor may order:

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

Treatment

Treatment will depend on the cause and severity of PH. When possible, the cause of PH is treated. Treating the cause will treat the PH. Treatment that may help to manage any type of PH includes:

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

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

Prevention

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

• Avoid use of street drugs like cocaine.
• Maintain proper weight. Weight may increase risk of certain types of PH.
• Talk to your 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.