Pulmonary Hypertension

Definition

Pulmonary hypertension is a type of high blood pressure that affects only the arteries in the lungs and the right side of your heart.

Pulmonary hypertension begins when tiny arteries in your lungs, called pulmonary arteries, and capillaries become narrowed, blocked or destroyed. This makes it harder for blood to flow through your lungs, which raises pressure within the arteries in your lungs. As the pressure builds, your heart's lower right chamber (right ventricle) must work harder to pump blood through your lungs, eventually causing your heart muscle to weaken and eventually fail completely.

Pulmonary hypertension is a serious illness that becomes progressively worse and is sometimes fatal. Although pulmonary hypertension isn't curable, treatments are available that can help lessen symptoms and improve your quality of life.

Symptoms

The signs and symptoms of pulmonary hypertension in its early stages may not be noticeable for months or even years. As the disease progresses, symptoms become worse.

Pulmonary hypertension symptoms include:

  • Shortness of breath (dyspnea), initially while exercising and eventually while at rest
  • Fatigue
  • Dizziness or fainting spells (syncope)
  • Chest pressure or pain
  • Swelling (edema) in your ankles, legs and eventually in your abdomen (ascites)
  • Bluish color to your lips and skin (cyanosis)
  • Racing pulse or heart palpitations

 Causes

Your heart has two upper and two lower chambers. Each time blood passes through your heart, the lower right chamber (right ventricle) pumps blood to your lungs through a large blood vessel (pulmonary artery). In your lungs, the blood releases carbon dioxide and picks up oxygen. The oxygen-rich blood then flows through blood vessels in your lungs (pulmonary arteries, capillaries and veins) to the left side of your heart.

Ordinarily, the blood flows easily through the vessels in your lungs, so blood pressure is usually much lower in your lungs. With pulmonary hypertension, the rise in blood pressure is caused by changes in the cells that line your pulmonary arteries. These changes cause extra tissue to form, eventually narrowing or completely blocking the blood vessels, making the arteries stiff and narrow. This makes it harder for blood to flow, raising the blood pressure in the pulmonary arteries.

Idiopathic pulmonary hypertension
When an underlying cause for high blood pressure in the lungs can't be found, the condition is called idiopathic pulmonary hypertension (IPH).

Some people with IPH may have a gene that's a risk factor for developing pulmonary hypertension. But in most people with idiopathic pulmonary hypertension, there is no recognized cause of their pulmonary hypertension.

Secondary pulmonary hypertension
Pulmonary hypertension that's caused by another medical problem is called secondary pulmonary hypertension. This type of pulmonary hypertension is more common than idiopathic pulmonary hypertension. Causes of secondary pulmonary hypertension include:

  • Blood clots in the lungs (pulmonary emboli)
  • Chronic obstructive pulmonary diseases, such as emphysema
  • Connective tissue disorders, such as scleroderma or lupus
  • Sleep apnea and other sleep disorders
  • Congenital heart disease
  • Sickle cell anemia
  • Chronic liver disease (cirrhosis)
  • AIDS
  • Lung diseases such as pulmonary fibrosis, a condition that causes scarring in the tissue between the lungs' air sacs (interstitium)
  • Left-sided heart failure
  • Living at altitudes higher than 8,000 feet (2,438 meters)
  • Climbing or hiking to altitudes higher than 8,000 feet (2,438 meters) without acclimating first
  • Use of certain stimulant drugs, such as cocaine

 Risk Factors

Although anyone can develop either type of pulmonary hypertension, older adults are more likely to have secondary pulmonary hypertension, and young people are more likely to have idiopathic pulmonary hypertension. Idiopathic pulmonary hypertension is also more common in women than it is in men.

Another risk factor for pulmonary hypertension is a family history of the disease. Some genes could be linked to idiopathic pulmonary hypertension. These genes might cause an overgrowth of cells in the small arteries of your lungs, making them narrower.

If one of your family members develops idiopathic pulmonary hypertension and tests positive for a gene mutation that can cause pulmonary hypertension, your doctor or genetic counselor may recommend that you or your family members be tested for the mutation.

Complications

Pulmonary hypertension can lead to a number of complications, including:

  • Right-sided heart failure (cor pulmonale).
  • Blood clots.
  • Arrhythmia
  • Bleeding.

 Tests & Diagnosis

  • Chest X-ray.
  • Echocardiogram.
  • Transesophageal echocardiogram.
  • Right heart catheterization.

Additional Tests:

  • Pulmonary function test.
  • Perfusion lung scan.
  • Computerized tomography (CT) scan.
  • Magnetic resonance imaging (MRI).
  • Open-lung biopsy.
  • Genetic tests

 Pulmonary hypertension classifications
Once you've been diagnosed with pulmonary hypertension, your doctor may classify the disease using guidelines developed by the New York Heart Association.

  • Class I. Although you've been diagnosed with pulmonary hypertension, you have no symptoms.
  • Class II. You don't have symptoms at rest, but you experience fatigue, shortness of breath or chest pain with normal activity.
  • Class III. You're comfortable at rest but have symptoms when you're physically active.
  • Class IV. You have symptoms even at rest.

 Medications

  • Blood vessel dilators (vasodilators).
  • Endothelin receptor antagonists.
  • High-dose calcium channel blockers.
  • Ambrisentan.
  • Anticoagulants.
  • Diuretics.
  • Oxygen.

 Surgeries

  • Atrial septostomy. If medications don't control your pulmonary hypertension, this open-heart surgery may be an option. In an atrial septostomy, a surgeon will create an opening between the left and right chambers of your heart to relieve the pressure on the right side of your heart. Atrial septostomy can have serious complications, including heart rhythm abnormalities (arrhythmias).
  • Transplantation. In some cases, a lung or heart-lung transplant may be an option, especially for younger people who have idiopathic pulmonary hypertension. Major risks of any type of transplantation include rejection of the transplanted organ and serious infection, and you must take immunosuppressant drugs for life to help reduce the chance of rejection.

 

 Source: mayo clinic.