The treatments for primary pulmonary hypertension are similar to those for systemic hypertension. Systemic hypertension is the elevation of blood pressure throughout the body, whereas for patients with PPH, the blood pressure is elevated specifically in the pulmonary artery. For systemic hypertension, a number of different drugs can be used, the most common of which are vasodilators that widen the blood vessels (vasodilate) and help to increase blood flow. Diuretic drugs can also reduce blood pressure by lowering the amount of fluid in the blood and thus requiring less force by the heart to pump the blood. Anticoagulants are common blood pressure lowering drugs. These drugs function by reducing the tendency of the blood to clot, thus allowing the blood to flow more freely.
The heart pumps blood from the right ventricle into the lungs through the pulmonary artery. The lungs then supply oxygen to the blood and capture carbon dioxide and other waste materials to be eliminated during exhalation. The blood then flows back to the heart, where the left ventricle pumps it throughout the body. The pumping action of the heart generates the blood flow; blood pressure is generated by resistance to this blood flow. If there is high resistance to this blood flow, then blood pressure rises. Hypertension is a medical term meaning that the blood pressure is higher than normal or that the resistance to blood flow is causing the blood pressure to be at an elevated state.
The normal pressure in the pulmonary artery is between 14 and 18 mm Hg. For patients with pulmonary hypertension, the pressure is normally about 30 to 50% higher or 25 to 30 mmHg. This high pressure has been linked to certain changes in the small blood vessels in the lungs. As the resistance to blood flow in these small vessels increases, it is harder for blood to flow through them and so the blood "backs up."
Primary pulmonary hypertension or PPH occurs when blood pressure in the pulmonary artery or the major blood vessel connecting the right heart ventricle and the lungs is higher than normal (The lungs are responsible for supplying the blood with oxygen and ridding the blood of carbon dioxide). Primary pulmonary hypertension arises for no apparent reason and is therefore synonymously known as idiopathic pulmonary hypertension or unexplained pulmonary hypertension. Primary pulmonary hypertension causes have been shown to include use of the diet drugs Fen Phen, Redux (dexfenfluramine) and Pondimin (fenfluramine). A higher pulmonary artery blood pressure causes the heart to work much harder to pump sufficient quantities of blood into the lungs. Over time, the heart muscles weaken and eventually may fail.
