原發性肺血壓高 近50% 對藥物無效 !!

原發性肺壓高極難察覺 【太陽報專訊】【本報訊】 原發性肺血壓高為罕見疾病，瑪麗醫院心胸外科部門主管區永谷說，臨床所見每年約有三、四名病人情況嚴重需換肺，當中有一至兩人惜未能等及換肺而不治。肺壓高分為原發性及繼發性，前者原因不明，後者與藥物、先天性心臟病等有關。香港大學醫學院心臟科臨床助理教授陳栢羲表示，原發性肺血壓高在診斷及治療上不簡單，建議有氣喘等徵狀的市民病向淺中醫。 氣喘心悸需注意 區永谷解釋，正常人肺壓是血壓的三分之一或四分之一，若超過血壓一半即屬於高。原發性肺血壓高病徵不明顯，例如氣喘、心悸、心律不整或疲倦，患者很多時以為運動後不適，因而未有及早察覺。 隨着患者肺動脈嚴重收窄，令肺壓比血壓更高，長遠可致右心衰竭。人工心肺機雖可暫緩病情，但一般只能為病人支撐兩至三周，其後或出現併發症，故必須把握時間移植肺臟。 陳栢羲透露，要診斷原發性肺血壓高，需要排除其他繼發性的可能性，當中可以涉及十至二十種檢查。一旦確診，醫生主要以藥物治療，包括口服藥物及吸入性藥物，作用是放鬆肺血管，紓緩壓力。不過，綜合本港及海外數據，約三成至一半病人對藥物無效，可能需要紓緩性手術，例如在心房之間開小洞，令血液「有路可走」，但只屬紓緩性質，最終需要考慮心肺移植。 區永谷說，以往本港每年換肺個案只有兩至三宗，今年截至九月已錄得十一宗雙肺移植，換心亦有十三宗，創了近二十年紀錄。他呼籲，雖然今年心肺移植成績較往年佳，但仍有不少病人輪候器官捐贈，待有心人大愛續命。

Pulmonary Hypertension Causes  The rare lung disease called pulmonary hypertension occurs when the arteries responsible for transporting the blood from the heart to the lungs are narrowed. Due to this disorder, the blood cannot pass through the vessels properly, which results in an increase of blood pressure to abnormally high levels. This process takes place in the pulmonary arteries and has consequences on the right ventricle of the heart. The heart has two upper and two lower ventricles that pump the blood to the lungs and rest of the body, which are affected by the disease. Due to pulmonary hypertension, the right ventricle needs to work harder to pump the blood, becoming enlarged and gradually weakened. When the blood vessels become completely narrowed or blocked, the arteries stiff and the heart loses the ability to properly pump blood to the lungs, it can cause right heart failure. In order to both prevent and treat this life-threatening disease, it is important to determine pulmonary hypertension causes so that a proper diagnosis and prognosis can be determined by a specialist.

General Knowledge On Pulmonary Hypertension Causes There is scientific evidence demonstrating that pulmonary hypertension causes may be related to injuries in the cell layer located in the small blood vessels of the lungs. However, the explanation is not that simple. The reasons for the injury are not completely understood, but it is known that it alters the interaction between the cells in question and the muscle cells in the vessel wall, causing a contraction of the muscle. There are, nonetheless, known causes that can contribute to the development of pulmonary hypertension. Among these reasons, the most important are the use of the appetite suppressant drug called "fen-phen" (dexfenfluramine and phentermine), which is already forbidden in the U.S. Chronic liver disease, liver cirrhosis and other liver diseases, scleroderma or systemic lupus erythematosus and other rheumatoid diseases, in addition to lung tumors, emphysema, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis or other lung conditions may also all act as pulmonary hypertension causes. Other diseases may contribute to the development of pulmonary hypertension, including aortic valve disease, left heart failure, mitral valve disease, congenital heart disease or other certain heart diseases, as well as thromboembolic disease. Low-oxygen conditions, which can be caused by high altitude, obesity, sleep apnea or other factors, and genetics are also risk factors. In addition, there are different types of pulmonary hypertension and the reasons for the development of the disease are not always understood.

Different Types of Pulmonary Hypertension Causes

Idiopathic Pulmonary Hypertension is when there is a lack of explanation for the disease. "Idiopathic" means exactly that the reason for the disease cannot be found. However, it is known that some of the patients carry a gene that comprises a risk factor for pulmonary hypertension.

Secondary Pulmonary Hypertension is a disease type caused by a primary medical problem and it is more common than idiopathic pulmonary hypertension. The most usual primary diseases that can result in secondary pulmonary hypertension include blood clots in the lungs, also known as pulmonary emboli, chronic obstructive pulmonary diseases like emphysema, scleroderma, lupus or other connective tissue disorders, sleep disorders, congenital heart defects, sickle cell anemia, chronic liver disease also known as cirrhosis, AIDS, lung diseases like pulmonary fibrosis, and left-sided heart failure, while the use of stimulant drugs like cocaine can also cause secondary pulmonary hypertension.

Eisenmenger Syndrome and Pulmonary Hypertension is a consequence of the syndrome, a congenital medical condition, which means people are born with it. When patients are born with this heart defect, there is a higher risk of developing a large hole between the two lower heart ventricles, which is called an entricular septal defect (VSD). Due to this defect, the blood circulation in the heart is affected, and the oxygen-carrying blood (red blood) and the oxygen-poor blood (blue blood) become mixed up. While normally the two types of blood circulate separately and the blood is supposed to be transported throughout the entire body, it keeps returning to the lungs, increasing pressure in the pulmonary arteries and causing pulmonary hypertension.