May 12, 2008
Pulmonary Arterial Hypertension
Pulmonary hypertension (PH) is a complex health condition involving high blood pressures in the arteries of the lung. A patient may have PH due to inadequate oxygen in the blood, as in chronic obstructive pulmonary disease (COPD – emphysema and chronic bronchitis) and idiopathic pulmonary fibrosis (IPF). PH also is seen in patients with diseases of the left side of the heart, such as those with mitral stenosis and heart failure.
An important subset of PH is pulmonary arterial hypertension (PAH). People with PAH face a progressive, life-threatening illness caused by high blood pressure in the arteries that carry blood from the heart to the lungs so it can pick up oxygen. PAH forces the heart to pump harder. Eventually, the strain causes the heart to enlarge and become less flexible. Less and less blood is able to flow out of the heart, through the lungs and into the body. Over time, and without treatment, the heart will fail, leading to severe disability and even death. There is no known cure for PAH.
PAH can occur in response to a variety of conditions such as scleroderma (autoimmune disease of the connecting tissues), cirrhosis of the liver, congenital heart defects, HIV infection, taking appetite suppressants (fenfluramine and dexfenfluramine) or chronic use of cocaine or amphetamines. Another possible cause is a family predisposition to the disease. A form with no known cause is called idiopathic PAH or IPAH.
Symptoms include:
extreme shortness of breath
excessive fatigue
dizziness
fainting
weakness
ankle swelling
chest pain
bluish lips, hands or feet
Who has PAH?
PAH affects men and women of all ages and all ethnic and racial backgrounds. While the true incidence is unknown, it is relatively rare, affecting 1 in 100,000 to 1,000,000 people. IPAH most commonly occurs in women in their mid-30s. About twice as many cases are reported in women as in men. PAH can get worse in pregnant women during labor and delivery, resulting in a high maternal death rate.
What happens in PAH?
As their disease progresses, PAH patients get weaker and more easily fatigued, so that their quality of life is affected. Even with treatment, pressure in the lungs will worsen and cause the right ventricle or right side of the heart to get larger. The patient can develop irregular heart rhythms (arrhythmias), which can lead to sudden death. In 2004, 314 people died from IPAH in the United States by IPAH; 241 were female and 73 were male.
Approximately 50 percent of people diagnosed with PAH die within five years. If untreated, the life expectancy is just two to three years from diagnosis. Prognosis is worse for patients who have heart failure, severe PAH or are over the age of 45 when diagnosed.
Even so, PAH patients have more options than ever before. Early diagnosis and treatment can reduce symptoms, improve quality of life, slow the progression of the disease and extend patients’ lives.
How is PAH diagnosed?
PAH is frequently misdiagnosed or diagnosed late because its symptoms can be confused with other conditions such as asthma, pneumonia, chronic obstructive pulmonary disease (emphysema and chronic bronchitis), heart failure and coronary disease. As of now, there is no specific test for PAH. Health care providers looking for possible PAH may conduct tests that include –
chest x-ray (picture of the heart and lungs)
electrocardiogram (electrical measure of the heart beat)
echocardiogram (ultrasound picture of the heart)
stress test (exercise test)
spirometry (breathing test)
right heart catheterization (procedure measuring pressure in the pulmonary arteries)
perfusion lung scan (image showing blood flow through the lungs)
How is PAH treated?
Treatments include anticoagulants, diuretics, calcium channel blockers, digoxin and prostacyclins. For IPAH, the newest and most often used treatments are phosphodiesterase-5 inhibitors (such as Sildenafil) and endothelin receptor antagonists (such as Bosantin). None of the drugs can cure or halt PAH progression, but they may relieve symptoms and slow the disease.
While each drug therapy works somewhat differently, the objective is to reduce the heart’s workload by allowing blood to flow more easily through the pulmonary arteries. The choice of treatment depends on how severe the patient’s disease is and how well the patient responds to therapy. Drugs may be combined to simultaneously target different aspects of the disease.
Some patients may need and be able to receive a heart-lung transplant. As technology advances, these transplants are becoming more successful.
What about PAH research?
The National Heart, Lung and Blood Institute currently supports more than 80 PAH research projects. For example, a recent study looked into different options for diagnosing PAH. A new non invasive tool to measure the pulmonary artery distensibility [stiffness] using MRI may be useful for evaluating PAH patients.
The American Lung Association, too, works with leading researchers to identify new interventions for PAH. The ultimate goals are to better understand PAH, find ways to diagnose PAH more quickly and find successful treatment strategies.
Getting help
Because PAH can be so debilitating and there is no cure, patients may feel frustrated and alone in their struggles. I recommend that PAH patients learn as much about their condition as possible and get to know other patients through support groups and other resources. As one patient says, “The more you learn, the better prepared you are to deal with it.”
For more information on PAH, go to the following websites:
General information – www.lungusa.org
Support groups – www.PHAssociation.org/connect
Treatment options – www.pph-net.org/pph-surgery-treatment.htm
Research – www.nhlbi.nih.gov
Posted by lungblogposter at May 12, 2008 03:05 PM
