Pulmonary arterial hypertension (PAH) is a rare, progressive disorder characterized by high blood pressure (hypertension) of the main artery of the lungs (pulmonary artery) for no obvious reason. The pulmonary artery is the blood vessel that carries blood from the heart through the lungs. Symptoms of pulmonary arterial hypertension include shortness of breath (dyspnoea) especially during exercise, chest pain, and fainting episodes. The exact cause of PAH is unknown and although treatable, there is no known cure for the disease.
Pulmonary arterial hypertension usually affects women between the ages of 20-50. Individuals with PAH may go years without a diagnosis, either because their symptoms are mild, nonspecific, or only present during demanding exercise. However, it is important to treat pulmonary arterial hypertension because without treatment, high blood pressure causes the heart to work much harder, and over time, these muscles may weaken or fail. The progressive nature of this disease means that an individual may experience only mild symptoms at first, but will eventually require treatment and medical care to maintain a normal lifestyle.
Signs and symptoms of pulmonary arterial hypertensionPulmonary arterial hypertension symptoms
are those that are normally associated with not having enough oxygen in the blood. In most cases, the initial symptom is shortness of breath
following slight exertion. Additional symptoms include excessive fatigue, weakness, chest pain, dizzy spells, and fainting episodes.
Affected individuals may also have a cough, sometimes with blood (haemoptysis), an enlarged heart
and liver, low blood pressure
(hypotension), and hoarseness due to compression of a nerve in the chest by an enlarged pulmonary artery.
In some cases, affected individuals may experience puffiness or swelling of the face, ankles, and feet due to abnormal accumulation of fluid (edema) within facial tissues.
Individuals with advanced stages of pulmonary arterial hypertension may have abnormal bluish discoloration of the skin due to low levels of circulating oxygen in the blood. In extreme cases, the right chamber of the heart is abnormally enlarged, resulting in diminished functioning of the right portion of the heart and, potentially, right heart failure. Other muscles in the heart can weaken or fail from strenuous use if not treated.
Causes of pulmonary arterial hypertension
The exact cause of pulmonary arterial hypertension
is unknown. Researchers believe that injury to the layer of cells that line the small blood vessels of the lung, perhaps then causing or in concert with changes in the smooth muscle cells in the vessel wall, initiates blood vessel disease. This injury, which occurs for unknown reasons, results in the contraction of smooth muscle and therefore narrows the vessel. Researchers also think that most people who develop pulmonary arterial hypertension have blood vessels that are particularly sensitive to certain internal or external factors and constrict, or narrow, when exposed to these factors.
Diagnosis of pulmonary arterial hypertension
It can often be hard to detect pulmonary arterial hypertension
in a routine clinical examination, even if the disease has progressed. Symptoms of pulmonary arterial hypertension are not unique and may be confused with many other diseases that cause a lack of oxygen in the blood. The diagnosis of pulmonary arterial hypertension is also one of exclusion, meaning that PAH is only diagnosed when other causes of pulmonary hypertension have been ruled out and there seems to be no known cause of the hypertension.
The tests that are commonly performed to diagnose pulmonary arterial hypertension and rule out other diseases are blood tests, pulmonary function tests, arterial blood gas measurements, X-rays of the chest, electrocardiography (ECG), and the “6-minute walk test”, which essentially measures how far an individual can walk in that time period. Ultimately, the majority of subjects undergo echocardiography
testing, followed by confirmation by cardiac catheterization with and without vasodilator testing.
Treatment of pulmonary arterial hypertension
Several medications are available such as iloprost (Ventavis) for the treatment of pulmonary arterial hypertension
. The treatment is inhaled through the mouth with the assistance of a special nebulizer, dilating the arteries and preventing the formation of blood clots.