What is it?
Pulmonary Arterial Hypertension (PAH) 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.
In the advanced stage of the disease, the blood vessels in the lungs are narrowed, thickened and stiff, causing it difficult for the heart to pump blood through, causing the heart muscle to weaken over time. Clots can form and block part of the vessel's lumen as well.
When pulmonary hypertension occurs in the absence of a known cause, it is referred to as idiopathic pulmonary arterial hypertension (IPAH). IPAH is extremely rare, occurring in about 2 to 10 persons per million population per year. Causes of pulmonary arterial hypertension include collagen vascular diseases (e.g. scleraderma, CREST syndrome or systemic lupus erythematosus ), Congenital heart diseases (shunts like ventricular and atrial septal defects), HIV infection, liver disease and diet drugs like fenfluramine and dexfenfluramine.
Common causes of secondary pulmonary hypertension include lung disorders (emphysema, lung fibrosis, sleep apnea), chronic pulmonary thromboembolism (chronic formation of blood clots in the pulmonary artery), and left heart disease (e.g. mitral stenosis).
How is it diagnosed?
These test are necessary in order for the doctor to assess your pulmonary arterial pressure and to determine the cause if the pressures are high.
Echocardiography - can estimate the pressure in the lung vessels and exclude cardiac conditions as a cause.
Six minute walk test - assess the ability of the patient to perform physical activities
Lung scans(CT and VQ scans) - to look for lung problems and for clots in the lung vessels.
Blood tests such as for SLE, liver disease, AIDS and others that can cause pulmonary hypertension
Lung Function Studies - assess the function of the lungs
Sleep studies - to exclude obstructive sleep apnea as a cause
Right heart catheterization - a definitive test to prove the diagnosis , to exclude shunts and left heart disease and to prognosticate the condition.
What are the symptoms?
The symptoms of this disease are rather common it is usually mistaken for asthma.
Common symptoms of Pulmonary hypertension include:
- Breathlessness, especially on exertion
- Tiredness - Dizziness during physical exertion
- Swollen ankle and legs
- Chest pain during physical activity
What is the treatment?
Pulmonary Hypertension has a poor prognosis and must be investigated. Patients who have symptoms need to be treated early. Outcomes of treatment is largely dependant on the cause of the disease. Treatment with PAH specific therapy has been shown to improve symptoms , exercise capacity and overall prognosis of the disease.
Drugs that are used specifically for treatment of Pulmonary Hypertension in Singapore include :
Phosphodiaterase V inhibitors such as Sildenafil (Viagra), Tadalafil (Cialis)
Endothelin Receptor Antagonists such as Bosentan (Tracleer).
Prostaclycline analogues such as Inhaled Illoprost (Ventavis), Intra-venous Epoprostanol (Flolan)
A patient can sometimes require treatment using two or three types of these drugs in combination as their disease progresses.
Drugs that are commonly used to complement the treatment of Pulmonary Hypertension include
Warfarin -This is an anticoagulant that thins the blood
Diuretics - Spironolactone, Frusemide (with Potassium Chloride) - these medications helps to remove water logged in the body
Long term Oxygen therapy - This is offered to patients with low oxygen saturation (< 90%), as oxygen is a good dilator of the pulmonary blood vessels.
Life with Pulmonary Hypertension
If you are diagnosed with Pulmonary Hypertension, you can still lead a fulfilling and meaningful life. Take appropriate measure to take care of yourself and avoid factors that can worsen your condition.
Medical therapy for your condition, when prescribed, should be adhered to strictly as much as possible. Follow up with your physician is necessary to review your condition and therapy at a regular basis. Medical treatment has successfully improved the outcome for many patients. You should not stop your medication unless recommended by your physician. Some new medications may interact with existing pulmonary medications (e.g. warfarin , Sildenafil) and may cause complications. Consult your doctor, when taking new medications.
You should be as active as your physical body can allow - do not over exert yourself. Activities such as leisurely walking or swimming are encouraged. As your symptoms can be made worse by physical exertion, only do as much as you feel comfortable with. You should not engage in competitive activities or do isometric exercises. If you are taking warfarin, you should avoid any form of contact sports and take special care whilst engaging in any form of exercise.
Ensure that you get your yearly flu vaccination and 5 yearly Pneumococcal vaccination as well. This will prevent you from getting severe lung infections. If you have a respiratory tract infection, seek medical attention early.
If you are planning to travel, ensure that the aircraft is pressurized and has supplemental oxygen available whilst on flight if necessary. You can check with the airline that you are travelling with. Most commercial carriers are pressurized and have oxygen supply on flight if needed.
Should you need any form of surgery, please remember to inform your surgeon, as general anaesthesia can be dangerous for you. You anaesthetist will usually need to consult your doctor in charge to discuss the surgical plan for you.
Female patients with Pulmonary Hypertension must not get pregnant as pregnancy increases the risk of death to both the mother and the foetus. Avoid pregnancy by practising safe and effective forms of contraception. Avoid oral contraception as these can aggravate pulmonary hypertension.
In the Pipeline
More and more new agents are being developed to treat Pulmonary hypertension. Atrial septostomy (making a hole in the heart to improve blood flow) and lung transplantation can be offered to patients who are failing their medical therapies.
There are clinical trials that recruit patients for evaluation of new therapies for use in the treatment of Pulmonary Hypertension. Enrolment in clinical trials will come with benefits of getting novel therapies early. If you would like to find out more, please contact:
Ms Margaret Choong at 67724081 or
Ms Li Geying at 67725456
Pulmonary Hypertension Support Group
The support group organises events from time to time to update individuals with the disease.
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