Pulmonary hypertension occurs when the blood pressure in the pulmonary arteries rises above normal. Symptoms of pulmonary hypertension include: shortness of breath (dyspnea) during routine activities, fatigue, chest pain, pounding heartbeat. When the disease gets worse, its manifestations may limit any physical activity.
There are three situations that may affect the pulmonary arteries and can cause hypertension:
– Narrowing of the arterial walls;
– Stiffness of the arterial walls, hereditary or acquired as a result of excessive multiplication of cells;
– Blood clots in the arteries.
These changes put in difficulty the heart function through which it pushes blood through the arteries and into the lungs. The pulmonary artery pressure increases and the heart is overloaded, the right ventricle weakens and deforms. As such, the heart can become unable to pump enough blood to the lungs. This causes heart failure (the most common cause of death in people diagnosed with pulmonary hypertension).
Types of pulmonary hypertension
Pulmonary hypertension includes a number of diseases, divided according to the World Health Organization, organized into five groups considering the cause. In all cases, the average pressure in the pulmonary artery exceeds 25 mmHg at rest or 30 mmHg during exercise. Normally, the arterial blood pressure is about 15 mmHg at rest.
1. The first group includes the following types of pulmonary hypertension:
a. idiopathic pulmonary arterial hypertension ( unknown cause);
b. Inherited pulmonary hypertension (passed from parents to children through genes);
c. Pulmonary hypertension caused by:
– Congenital heart disease;
– Use of certain medications and drugs (such as cocaine);
– Thyroid disorders.
2. The second group includes pulmonary hypertension due to left heart disease (affecting the left ventricle of the heart), mitral valve disease or high blood pressure.
3. The third group includes pulmonary hypertension caused by lung diseases such as chronic obstructive pulmonary disease, sleep disorders causing respiratory problems (sleep apnea) and interstitial lung disease. Interstitial lung disease refers to the group of lung diseases which cause scarring of the lung tissue.
4. The fourth group includes pulmonary hypertension due to coagulation disorders and diseases that result in forming blood clots in the lungs.
5. The fifth group is the one that includes pulmonary hypertension caused by various diseases or disorders: sarcoidosis, Langerhans cells Histiocytosis , Lymphangioleiomyomatosis, but also lung tumors that put pressure on the pulmonary blood vessels.
Sometimes, in order to describe different types of hypertension, other terms are used:
– Pulmonary hypertension with unknown cause is called primary or idiopathic pulmonary arterial hypertension.
– When the pulmonary hypertension occurs or is caused by other diseases or conditions is called secondary pulmonary hypertension.
Causes of Pulmonary Hypertension
In the case of pulmonary hypertension, high blood pressure can be caused by a change in the cells of the pulmonary arteries. These changes result in the formation of extra tissue that narrows the blood vessels and blocks (this is one reason why they become rigid and narrow). Because of this, the blood flow will be slowed, and the blood pressure in the pulmonary arteries will rise.
Idiopathic pulmonary hypertension
When the cause of pulmonary arterial hypertension is unknown, it is called idiopathic pulmonary hypertension. Some people who experience this condition may have a gene that represents a risk factor for the development of pulmonary hypertension. However, in most cases, there is not a known cause that could cause the disease.
Secondary pulmonary hypertension
Pulmonary hypertension generated by a medical problem is called secondary pulmonary hypertension. This is more common than idiopathic pulmonary hypertension.
The causes may be:
– Blood clots in the lungs (pulmonary embolism);
– Chronic obstructive pulmonary disease (emphysema);
– Connective tissue disease (scleroderma or lupus);
– Sleep apnea and other sleep disorders;
– Congenital heart disease;
– Sickle-shaped cell anemia;
– Chronic diseases of the liver (cirrhosis);
– Pulmonary disease (pulmonary fibrosis);
– Heart failure of left heart;
– Life at altitudes above 2,500 meters;
– Climbing or hiking at 2,500 meters without prior adaptation of this altitude;
– Drug (cocaine).
Symptoms of Pulmonary Hypertension
Signs and symptoms of pulmonary arterial hypertension may include:
– Shortness of breath during routine activities (dyspnea);
– Chest pain;
– Increased heart rate (fast pulse).
As the pulmonary hypertension worsens, the physical activities become more difficult. At this stage, the manifestations could be:
– Feeling dizzy, especially during physical activity;
– Fainting (syncope);
– Swelling of the legs and ankles (edema);
– Cyanosis: blue color of the lips and even skin.
Although anyone can develop any type of pulmonary hypertension, older people are prone to secondary pulmonary hypertension and the younger people to idiopathic pulmonary hypertension. This latter type is more common in women than in men.
Another risk factor is the presence of the disease in the family history. A person can inherit genes that predispose to the development of idiopathic pulmonary hypertension. Genes could cause an overgrowth of cells in the pulmonary arteries, narrowing them.
If one member of a family shows idiopathic pulmonary hypertension and the tests confirm the mutation, your doctor may recommend that the rest of the family members do specific tests to confirm or rule out the presence of the gene that triggers the disease.
Tests and diagnosis for Pulmonary Hypertension
Pulmonary hypertension is difficult to diagnose early because it cannot easily be detected after a routine physical exam. Even when the disease is in an advanced stage, signs and symptoms are similar to those of cardiovascular disease as well as other lung diseases. The doctor will ask for several tests to rule out other possible reasons for your status.
The investigations that contribute to the correct diagnosis of pulmonary hypertension are:
– Chest X-ray – it will check if the pulmonary arteries and right ventricle of the heart are enlarged. However, in about a third of the people with hypertension, the radiography is normal.
– Echocardiogram – Sometimes the doctor will recommend echocardiography to determine how well the heart functions under stress. In this case, the investigation will be done before and after you do some exercise on the treadmill or the stationary bike.
– Transesophageal echocardiography – if you are unable to obtain clear images of the heart and lungs through standard echocardiography, the doctor may recommend transesophageal echocardiography. In this procedure, under local anesthesia, a flexible tube containing a transducer will be introduced into the esophagus. From here, the transducer will obtain detailed images of your heart
– Right heart catheterization (angiogram) – right heart catheterization allows the doctor to measure the pressure of the main pulmonary artery and the right ventricle. The investigation is used to determine the effect medication can have on the pulmonary hypertension. The test is performed under local anesthesia in the hospital, but the patient can go home immediately after the procedure, although supervised.
Your doctor may require further analysis for checking the lungs and pulmonary arteries, including:
– Test of lung function (spirometry) – During the test you will blow into an instrument called a spirometer.
– Lung perfusion scintigraphy
– Magnetic Resonance Imaging
– Lung biopsy – aims to detect a possible cause of secondary hypertension. It will confirm the need of certain types of treatment or the discontinuation of drug therapy.
If one of your family members suffers from pulmonary hypertension, the doctor will recommend genetic testing in this direction. If test results are positive, your doctor may recommend other family members to undergo the same investigation.
Treatments and drugs for Pulmonary Hypertension
Pulmonary arterial hypertension cannot be cured, but treatment can help relieve symptoms and slow the progression. The treatment of pulmonary arterial hypertension involves drugs, various procedures and therapies. It will depend on the type of pulmonary hypertension that you have and the severity of the disease.
1. Group 1 pulmonary hypertension
Includes pulmonary hypertension inherited, idiopathic (for reasons which are unknown) or caused by certain conditions. Treatment includes the following medicines or medical procedures:
a. Medications to relax the blood vessels of the lungs (to improve blood flow) and to reduce excessive proliferation of cells from the blood vessels. Examples of such drugs include phosphodiesterase-5 inhibitors, prostanoids, antagonists of the endothelin receptors and calcium channel blockers.
To know which of these drugs will work best, you do a test for acute vasoreactivity. This test will be done during right heart catheterization and shows how the pressure in the pulmonary arteries reacts to certain medications.
b. Medical and Surgical Procedures – atrial septostomy is a procedure in which a flexible and thin tube (catheter) is inserted through a blood vessel in the leg and threaded to the heart. The tube is then directed to the wall that separates the right atrium from the left (the two upper chambers of the heart). This wall is called septum. At the top of the tube there is a tiny inflated balloon to create an opening to the atrium. The procedure relieves pressure in the right atrium and increases blood flow.
– Lung transplantation.
2. Group 2 pulmonary hypertension
It involves the relationship of hypertension with left pulmonary diseases affecting the heart, such as mitral valve disease. Treating this condition will help stabilize the blood pressure. Treatments can include lifestyle changes, medications and surgery.
3. Group 3 hypertension
If you have this kind of hypertension oxygen therapy is required, which aims to raise the level of oxygen in the blood. Oxygen therapy can be done either at home or at the hospital.
Your doctor may recommend other treatments if you have another lung disease associated.
4. Group 4 pulmonary arterial hypertension
Those who suffer from this type of hypertension will follow a treatment with anticoagulants, which are designed to prevent the formation of clots or their growth. In some cases, surgical intervention is needed to remove the scars from the pulmonary arteries formed as a result of the existence of older blood clots.
5. Group 5 hypertension
This type of hypertension can be caused even by a tumor that presses the pulmonary blood vessels. In this case, the pulmonary hypertension is treated as a result of the healing of its cause.
All types of pulmonary arterial hypertension
There can be used several treatments for all types of hypertension.
– Diuretics – which help eliminate accumulated fluid in the body that causes the edema, swollen ankles and feet
– Anticoagulants – drugs that prevent blood clots or increase them.
– Oxygen therapy – raises the level of oxygen in the blood.
– Physical activity – regular exercise can help to improve general health and to maintain an individual’s ability to be active.