Pulmonary hypertension is a lung disorder in which blood pressure in the pulmonary artery rises above normal levels. The pulmonary artery is the blood vessel carrying oxygen-poor blood from the heart to the lungs. Pulmonary hypertension is present when the mean pulmonary artery pressure is greater than 25mmHg at rest or 30mmHg with exercise. This abnormally high pressure (pulmonary hypertension) is associated with changes in the small blood vessels in the lungs, resulting in an increased resistance to blood flowing through the vessels. This increased resistance, in turn, places a strain on the heart as it has to work against a higher resistance to pump blood to the lungs.

 

Types of Pulmonary Hypertension

 

Pulmonary hypertension could be associated with a variety of conditions (secondary pulmonary hypertension) or it may occur without an identifiable underlying cause (primary, idiopathic, or unexplained pulmonary hypertension). Secondary pulmonary hypertension can result from lung disease, heart disease, low oxygen in the blood (hypoxia) and obstruction of the pulmonary vessels (from clots, foreign body, parasites and certain blood disorders). Some conditions may be associated with clinical primary pulmonary hypertension including cirrhosis, AIDS, connective tissue diseases, and certain toxins.
Primary pulmonary hypertension (PPH) is a rare condition, with an estimated incidence of approximately 1in every million patients per year, although it appears to be becoming more frequently detected by simple noninvasive means, such as echocardiographic examination. The illness most often occurs in young adults and is more common in women.

 

Symptoms of PPH:

 

The most common symptoms of PPH are tiredness and shortness of breath with exertion. Fainting spells, dizziness, ankle or leg swelling, racing pulse and chest pressure or pain are also typical symptoms. PPH is rarely picked up in a routine medical examination. Even in its later stages, the signs of the disease can be confused with other conditions affecting the heart and lungs. PPH remains a diagnosis of exclusion. This means that it is diagnosed only after the doctor finds pulmonary hypertension and cannot find other reasons for the hypertension. The evaluation of patients with pulmonary hypertension in order to determine optimal treatment is a meticulous process.

 

Treatment of PPH:

 

The course of PPH is often one of steady deterioration and reduced life expectancy. The untreated patients have a probability of survival of 68% at one year, 48% at three years, and 34 % at five years.  Treatment of PPH varies according to the stage of the disease. At present, approximately one-quarter to one-half of patients can be treated with calcium channel blocking drugs given by mouth. By relaxing the smooth muscle in the blood vessels, these calcium channel blockers improve the ability of the heart to pump blood. Prostacyclin (epoprostenol, PGI2) is normally produced in cells of the body and dilates the blood vessels.  Now it is manufactured as a drug, which can be given as a continuous intravenous infusion by a battery powered pump. This requires placement of a catheter in one of the central veins. It has shown to improve survival and exercise tolerance of these patients