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PULMONARY HYPERTENSION INTRODUCTION BRIEF HISTORY WHAT IS PH? WHAT CAUSES PH? SIGNS AND SYMPTOMS DIAGNOSIS OF PH TREATMENT OF PH INTRODUCTION In the human body, there are two types of circulation that enable distribution of blood throughout the body. The portion that pumps oxygenated blood from the left side of the heart via the left ventricle to all parts of the body is known as the SYSTEMIC CIRCULATION. On the other hand, the portion that pumps deoxygenated blood from the right side of the heart via the right ventricle into the lungs to obtain oxygen is referred to as the PULMONARY CIRCULATION. Millions of people are affected by a condition known as high blood pressure (hypertension) whereby the blood travels through the bodys arteries at a pressure higher than normal. PULMONARY HYPERTENSION is a far less common type of high blood pressure that affects specifically the arteries in the lungs. Pressures in the lung arteries are normally significantly lower than the pressures in the systemic circulation. Pulmonary hypertension occurs when the pressure in the pulmonary circulation becomes abnormally elevated. It is a serious condition that becomes progressively worse and eventually proves fatal. INTRODUCTION INTRODUCTION An estimated of 500 1000 new cases are diagnosed annually. There is an incidence of about 2-3 per million per year and a prevalence of 15 per million. This disease can occur in men, women and children of all ages. However, it is most common in females between 20 and 40 years old, with twice as many cases reported in women then men. The condition is rare in children but is sometimes seen in infants born with heart defects. Pulmonary hypertension may be a primary or secondary cause of hypoxia in neonates. H I S T O R Y The first reported case 1891 E. Romberg, German doctor published description of a patient who, at autopsy, showed thickening of the pulmonary artery but no heart or lung disease In 1951, 39 cases were reported by Dr. D.T. Dresdale in the United States. The illness received its name. Between 1967 and 1973, a 10-fold increase in unexplained pulmonary hypertension was reported in central Europe. The rise was subsequently traced to aminorex fumarate, an amphetamine- like drug introduced in Europe in 1965 to control appetite. It was later removed from the market. WHAT IS PULMONARY HYPERTENSION? Ordinarily, blood vessels in the lungs provide less resistance to blood flow than blood vessels in the rest of the body do. Hence, blood pressure is usually much lower in the lungs. While pressure in general circulation is about 120/80 mm Hg, in the pulmonary arteries, it is only around 25/15 mm Hg. Mean (average) pulmonary artery pressure = number between highest and lowest pressures Normal at rest : 14 mm Hg Pulmonary hypertension at rest : 25 mm Hg during exercise : 30 mm Hg Primary Pulmonary Hypertension no underlying cause for the high blood pressure in lungs likely to begin with spasm of the muscle layer in pulmonary arteries patients are rather sensitive to substances that cause blood vessels to constrict may have an inherited predisposition for the disease Secondary Pulmonary Hypertension results directly from another medical problem most probable from diseases that impedes flow of blood through lungs or that causes periods of low oxygen in blood eg. Chronic Obstructive Pulmonary Disease, scleroderma, sleep apnea, pulmonary fibrosis, lung diseases such as asbestosis Abnormally high BP in pulmonary arteries Increased pressure damages large and small pulmonary arteries Blood vessel walls thicken Cannot transfer oxygen and carbon dioxide normally Levels of oxygen in blood fall Constriction of pulmonary arteries Further increase in pressure in pulmonary circulation Pulmonary Hypertension right side of heart must work harderpush blood through pulmonary arteries to lungs right ventricle thickens and enlarges cor pulmonale Heart Failure In some people, the bone marrow will produce more red blood cells to compensate for less of oxygen in blood leading Polycythemia Extra RBCs cause the blood to become thicker and stickier, further increasing the load on the heart Pulmonary Embolism Functional Classification A. Class I- Patients with pulmonary hypertension but without resulting limitation of physical activity. Ordinary physical activity does not cause undue dyspnoea or fatigue, chest pain, or near syncope. B. Class II- patients with pulmonary hypertension resulting in slight limitation of physical activity. They are comfortable at rest. Ordinary physical activity causes undue dyspnoea or fatigue, chest pain, or near syncope. C. Class III- patients with pulmonary hypertension resulting in marked. Limitation of physical activity. They are comfortable at rest. Less than ordinary activity causes undue dyspnoea, fatigue, and chest pain or near syncope. D. Class IV -patients with pulmonary hypertension with inability to carry out any physical activity without symptoms. these patients manifest signs of right heart failure. Dyspnoea and /or fatigue may be present even at rest. Discomfort is increased by any physical activity WHAT CAUSES PULMONARY HYPERTENSION? Although the exact cause of primary pulmonary hypertension is unknown, scientists believe that most people who develop the disorder are especially sensitive to substances that cause blood vessels to constrict. Cocaine and fenfluramine (fen-phen), which was withdrawn from the market in 1997, are two of the substances that may contribute to PH in many people. Other people with PH have an inherited predisposition for the disease. In these people, PH is triggered by another medical condition such as chronic liver disease (cirrhosis), AIDS, sickle cell anemia, scleroderma and lupus. Pulmonary hypertension resulting directly from another medical problem is called secondary pulmonary hypertension. Medical conditions that may lead to secondary PH include : blood clots in the lungs (pulmonary emboli) chronic obstructive pulmonary disease such as emphysema connective tissue disorders, such as scleroderma sleep apnea upper airway obstructed during sleep congenital heart disease obesity with reduced ability to breathe (Pickwickian syndrome) neuromuscular diseases involving respiratory muscles HIV infection lung diseases such as pulmonary fibrosis (causes scarring in the tissue between the lungs air sacs) Left-sided heart failure hearts left ventricle weakens and cannot pump out enough blood increase in pressure backs up through pulmonary veins to arteries in lungs High Altitude above altitude of 8000 feet - may develop PH low blood oxygen (hypoxemia) constricts small pulmonary arteries climb to high elevations without first becoming acclimated risk of pulmonary edema too air sacs filled with fluid instead of with air, always associated with PH The overall rise in blood pressure in PH is the end result of a process which begins with changes in the endothelial cells that line the lungs arteries. Changes causes formation of extra tissue blockage in vessels Scarring (fibrosis) usually also occurs arteries stiff and narrow These causes increased resistance to blood flow which raises pressure in the pulmonary arteries. Less often, PH is caused by extensive loss of lung tissue from surgery/trauma. Injury to endothelial cells leads to overproduction of endothelin key cause of blood vessel scarring and spasm others may need a transplant. Some patients might also require supplemental oxygen delivered through nasal prongs or a mask if breathing becomes difficult whereas some need oxygen around the clock. In severely affected cases, a heart-lung, single lung of double lung transplantation may be appropriate. PH patients respond differently to different medicines that are prescribed to dilate or relax blood vessels and no one drug can be said to be consistently effective in all patients. Because individual reactions vary, different drug have to be tried before chronic or long-term treatment begins. During the course of disease, the amount and type of medicine may also have to be changed. To find out which medicine works best for a particular patient, the drugs should be evaluated via cardiac catheterization. This way, they can see the effect of the medicine on the patients heart and lungs. They can also adjust the dose to reduce the side effects such as systemic low BP, nausea, angina, headache etc that may occur. To determine whether a drug is improving a patients condition, both the pulmonary pressure and the amount of blood being pumped by the heart (cardiac output) must be evaluated. Calcium Channel Blockers blocks entry of calcium into muscle cells of heart & arteries improve ability of heart to pump blood relaxes smooth muscle in walls of heart and blood vessels amlodipine (Norvasc), diltiazem (Cardizem, Tiazac), nifedipine (Adalat, Procardia), nicardipine (Cardene) etc. only small number of people with PH respond to them side effects constipation, nausea, headache, rash, edema, drowsiness, dizziness, low blood pressure Blood Vessel Dilators Prostacyclin substance that acts like a hormone (prostaglandin) imitates behaviour of natural prostacyclin powerful vasodilator and anti-clotting agent prevent blood clots from forming given intravenously through catheter bridge to help those waiting for transplant Epoprostenol (Flolan) - 1st vasodilator approved by FDA Ilopost - inhaled through nebulizer Treprostinil - injected under skin side effects - jaw pain, nausea, leg cramps etc need comprehensive follow-up care Endothelin Receptor Antagonists available in pill form reverse effect of endothelin (blood vessels constriction) Bosentan (Tracleer) - may improve stamina of people with PH not for pregnant women need monthly liver monitoring - risk of liver complications Phosphodiesterase Inhibitors Revatio contains sildenafil same active ingredient used in Viagra blocks the enzyme phosphodiesterase accentuates actions of nitric oxide opens blood vessels in the lungs - dilation side effect - vision problems Anticoagulant warfarin (Coumadin) prevent formation of blood clots within pulmonary arteries risk of bleeding complications prevent normal blood coagulation periodic blood tests check how well the drug is working more than 100 drugs can interact with anticoagulants Diuretics water pills eliminate excess fluid from body reduces amount of work heart has to do limit fluid buildup in the lungs improve exchange of gases in lungs Oxygen oxygen therapy especially for those who live in high altitude or have sleep apnea continuous use of oxygen through nasal prongs/oxygen mask relieve shortness of breath Cardiotonics strengthen the contractions of the heart heart does not need to beat as often to circulate adequate blood for body Transplants surgical interventions considered only in extreme cases treatment for severe secondary PH if treatment of the underlying disorder fails surgically replace damage organs with healthy donated organs lung and/or heart transplantation most common : single-lung transplant, fewer complications than double-lung or heart-lung transplant lung transplant - improvement in structure and functioning of right ventricle major risks : rejection of transplanted organ, serious infection take immunosuppressant drugs for life help reduce chance of rejection survival rate is about 60% per year and 37% per 5 years Lung and heart for transplant Other treatment procedures Dilation Atrial Septostomy experimental procedure use in patient with severe PH makes a small hole in the heart, slowly enlarging it to relieve some of the pressure in the hearts right side shunts blood across the atrial septum and into the left side of the heart similar to balloon atrial septostomy naturally occurring hole present at birth is enlarged to help those with congenital heart defects Other areas of research for treatment of PH includes gene therapy and stem cell research. Pregnancy and PH The consensus of medical opinion is that PH and pregnancy is very dangerous. The life of the mother and baby are put at great risk. Pregnancy can really take its toll on a womans body. For example, heart rate speeds up and the immune system does not work quite as well. For a woman whose body already has to deal with a severe illness, pregnancy can actually have catastrophic consequences. The risk of pregnancy-related death in women with PH is substantial reported to be as high as 30-50%. Some drugs commonly used to treat PH can be harmful to the developing fetus (e.g. warfarin). Because of this twofold risk to both mother and baby, use of some form of birth control to avoid pregnancy is strongly advised in women of childbearing age with PH. Children and PH Untreated PH in children worsens more quickly than the same condition in adults. Children also change more quickly than adults and have to be watched closely. However, with treatment, children appear to have an overall better prognosis than adults. Children are responsive to the same treatments as adults. Treatment for PH is lifelong. The treatment used has to be individualized and adjusted according to how the child is responding. Unfortunately, there is no minimum age for PH sufferers. Newborn, young children, teenagers and even in early adulthood, PH may occur. A child with PH can still go to school, dance, play sports or ride a bike. Just like other children, a child with PH can help themselves by eating a healthy and balanced diet and have good rest periods. It is really important to have a greater degree of caution in allowing other non-PH doctors prescribe medication for a child with PH. Children and PH It is hard but children with PH should be treated as normally as possible. The child will be happier and feel safer if they are treated just like the rest of the family. News From Home KUALA LUMPUR : Siti Salmah Jasni is on a heart- and-lung support machine and still in critical condition. A statement issued by the National Heart Institute (IJN) said Siti Salmah is awake and able to respond to doctors. Siti Salmah underwent a six-hour h