|
What is PAH / PPH?
Pulmonary Hypertension is a rare blood vessel disorder of the lung in which the pressure in the pulmonary artery (the blood vessel that leads from the heart to the lungs) rises above normal levels and may become life threatening. When pulmonary hypertension occurs in the absence of a known cause, it is referred to as pulmonary arterial hypertension (PAH) or primary pulmonary hypertension (PPH). Pulmonary Arterial Hypertension / Primary Pulmonary Hypertension starts when the small vessels that supply blood to the lungs constrict, or tighten up. It is more difficult for blood to get through to the lungs, and the heart must pump harder to overcome the resistance. As time passes, scarring (or fibrosis) of the vessels makes them stiffer and thicker, and some may be completely blocked. The extra stress 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, and more and more symptoms start to show. What are some of the Clinical Effects of PAH/PPH?
Increased pressure in the pulmonary arteries results from a progressive narrowing of the pulmonary arterioles - the smaller branches of the main pulmonary arteries. One direct effect of these abnormally elevated pressures is blood leakage from the pulmonary vessels. A blood-producing cough is oftentimes an indicator of leakage from the pulmonary vessels. The increased pressures in the pulmonary arteries and arterioles can trigger a cyclical chain of adverse events beginning with a decrease in the blood's oxygen content. The body then responds to this low oxygen content by increasing its production of red blood cells. This is known as polycythemia. By doing so, the body attempts to compensate for the blood's low oxygen content by increasing the number of oxygen carriers, i.e. the red blood cells.
As the red blood cell count increases, the blood thickens, making the heart (already under increased stress from the elevated pressures) work that much harder to pump the thicker blood throughout the body. This further increases arterial pressures and can lead to congestive heart failure.
How will I know if I have pulmonary arterial hypertension / primary pulmonary hypertension? PAH / PPH is often not diagnosed in a timely manner because its early symptoms can be confused with those of many other conditions. Some of the symptoms of PAH/PPH include: -- Breathlessness or shortness of breath
-- Feeling tired all the time
-- Dizziness, especially when climbing stairs or upon standing up
-- Fainting-often the symptom that brings people to their doctors
-- Swollen ankles and legs
-- Chest pain, especially during physical activity To establish a diagnosis of PH, a series of tests are performed that show how well a person's heart and lungs are working. These tests may include: -- Echocardiogram
-- Electrocardiogram (ECG)
-- Right heart catheterization
-- Six-minute walk test
-- Assessment of function in tasks of daily living If these tests show that a person definitely has PH, other kinds of diagnostic tests may be ordered to aid in identifying the cause, including: -- A computed tomography (CT or CAT) scan to rule out a pulmonary embolism or lung disease
-- A pulmonary function test to rule out obstructive lung disease
-- A formal sleep study to rule out sleep apnea
-- Laboratory tests to rule out hepatitis, collagen disease, HIV, or other conditions When no cause can be found, the diagnosis is pulmonary arterial hypertension (PAH) / primary pulmonary hypertension (PPH). Pulmonary hypertension related to or caused by another illness is known as secondary pulmonary hypertension, or SPH.) Other forms of pulmonary hypertension In 1998, the World Health Organization (WHO) sponsored a meeting of PH specialists with the goal of creating a standardized system for defining different kinds of PH. The committee proposed that the disease be divided into the following five categories of pulmonary hypertension: 1. Pulmonary arterial hypertension (PAH)
The pulmonary artery is the large vessel that carries blood from the heart into the lungs so it can pick up oxygen. Most cases of PH affect this artery and the hundreds of tiny blood vessels that branch off from it. This category includes two types of PH:
Primary pulmonary hypertension (PPH) can occur at random, without any apparent cause. Other times, the disease can be inherited; it is estimated that at least 10 percent of PPH cases occur in families where at least one other person has had it.
PAH related to other causes appears to be similar to PPH, but is actually associated with exposure to toxins or the effects of other diseases. These can include: -- Collagen vascular disease (scleroderma, lupus, rheumatoid arthritis)
-- Congenital heart disease
-- Chronic liver disease
-- Human immunodeficiency virus (HIV)
-- Use of diet drugs such as fenfluramine or dexfenfluramine
-- Use of cocaine, methamphetamine, or other street drugs
-- Persistent pulmonary hypertension of the newborn 2. Pulmonary hypertension associated with disorders of the respiratory system -- Emphysema
-- Interstitial lung disease
-- Sleep apnea
-- Chronic exposure to high altitude 3. Pulmonary hypertension due to chronic thrombotic or embolic disease -- Blood clots in pulmonary arteries
-- Pulmonary embolism (caused by clot, tumor, or foreign matter in the lungs)
-- Sickle cell disease 4. Pulmonary hypertension due to disorders directly affecting the pulmonary blood vessels -- Inflammatory diseases such as schistosomiasis or sarcoidosis
-- Pulmonary capillary disease 5. Pulmonary venous hypertension (PVH) is caused by diseases of the left side of the heart, such as mitral valve disease or a poorly performing left ventricle. This can cause increased pulmonary artery pressures, but rarely leads to severe PAH.
|
