Pulmonary hypertension or also called pulmonary arterial hypertension (PAH) is a progressive disorder that raises the pressure level in the pulmonary artery and the right side of the heart. Although it is a rare disease, it can become very serious because the blood vessels (pulmonary artery and veins) that carry blood from the heart to the lungs for oxygenation become narrowed, hardened and can even become blocked, which can lead to very serious and fatal complications.
The increased pressure in the pulmonary artery represents an overload for the right ventricle, which is responsible for propelling blood to the lungs. With the passage of time, the right ventricle becomes insufficient to support this overload and begins to fail, which leads to the affected patient’s intolerance to physical activity, shortness of breath (dyspnea), swelling first of the lower limbs and then of the abdomen, among other discomforts.
Risk factors that may predispose to the development of PAH include medications, established conditions and diseases.
Medications and toxic substances: Phenfuramine, dexfenfuramine (established cause of PAH), amphetamines, methamphetamines, L-tryptophan (very likely to cause PAH), cocaine, phenylpropanolamine, chemotherapy drugs, serotonin reuptake inhibitors (fluoxetine, sertraline), possible causes of PHT; antidepressants, tobacco, estrogens, less likely to cause PAH.
Established conditions: female sex, pregnancy, obesity, systemic arterial hypertension.
Diseases: HIV (established cause of PAH). Portal vein hypertension, collagen diseases, such as lupus, dermatomyositis, among others, congenital diseases of blood circulation (all very likely causes of PAH). Thyroid disease (unlikely cause).
Types of pulmonary hypertension
There are five types of pulmonary arterial hypertension which include:
Own pulmonary arterial hypertension.
It may be of unknown cause or caused by drugs, of hereditary cause, or caused by present diseases and medical conditions.
Pulmonary hypertension due to heart failure
When the left heart has difficulty or failure to pump oxygenated blood from the lungs to the rest of the body, this blood backs up into the lungs, which increases the pressure in the lungs. This is the most common form of PAH.
Pulmonary hypertension due to lung disease
This type of PAH includes chronic lung disease and tissue hypoxia (low oxygen in the blood and tissues). The main causes of chronic lung disease include chronic obstructive pulmonary disease (COPD), cystic fibrosis, sleep apnea, and interstitial lung disease. It can also occur in people who live in high altitude areas for a long period of time due to the low oxygen pressure in those areas.
Pulmonary hypertension due to blood clots in the lungs
In this type of PAH, blood clots may form in the lungs that are difficult to dissolve due to blood clotting disorders, which may slow or block blood flow, which can increase the pressure in the pulmonary circulation. This form of pulmonary hypertension is called chronic thromboembolic hypertension.
Pulmonary hypertension due to unknown causes
This type of PAH may be secondary to other diseases whose mechanism of action is not yet well understood. These secondary conditions include: sarcoidosis, sickle cell anemia, chronic hemolytic anemia, patients who have had their spleen removed (splenectomy), and certain metabolic disorders.
At the onset of the disease, signs and symptoms may not be overt or specific, being more evident when there is advanced damage. Thus, signs of the presence of PAH may not be visible for months or years, so primary care physicians should make an early diagnosis of this disorder, which is then evaluated and treated by a specialist physician. The most prominent signs and symptoms of PAH include:
1. Tiredness and fatigue.
2. Shortness of breath both during physical activity and at rest.
3. Chest pain and pressure.
5. Syncope (fainting).
6. Bluish discoloration of the lips or skin, known as cyanosis.
bulging abdomen (due to fluid accumulation).
7. Swelling of the legs and ankles.
8. Weakness that may become extreme.
9. Increased heart rate.
10. loss of appetite
The diagnosis of this disease can be very difficult since sometimes symptoms do not appear until advanced stages of the disease. Medical specialists (cardiologist and pulmonologist) may order some tests as a diagnostic aid to detect the presence of this disorder. Some of the tests include blood tests, echocardiogram, electrocardiogram, chest x-ray, right heart catheterization, among others.
Other diagnostic tests can be used to assess the state of lung tissue and other compromised devices and systems: computed tomography, magnetic resonance imaging, lung scintigraphy, lung capacity tests, polysomnography (sleep apnea screening), autoimmune disease testing, pulmonary ventilation/perfusion tests, and in some cases a biopsy of lung tissue can be performed to clarify the diagnosis of PAH.
This disease requires a multidisciplinary team that includes several specialists such as cardiologist, pulmonologist, cardiothoracic surgeon, among others. It should be emphasized that pulmonary hypertension is an incurable disease, since there is no specific drug that can treat it. The main objective of treatment is aimed at controlling symptoms and preventing as much lung damage as possible. It is important to treat and control diseases that can cause PAH, such as heart disease, lung disease, and obstructive sleep apnea.
Some of the medications to control PAH include:
1. Blood vasodilators.
2. Blood thinners.
5. Calcium channel blockers, among others.
Surgical procedures include the opening of the upper cardiac cavities to reduce pulmonary pressure and ultimately heart and lung transplantation, mainly in young patients with pulmonary hypertension of unknown cause.
Pulmonary hypertension can appear unexpectedly, even years later, when the disease is in advanced stages. Thus, there is no effective way to prevent it, however, risk factors can be avoided:
1. Prevent overweight.
2. If there is a family history of the disease, it is important to detect and control it early.
3. Do not engage in strenuous physical activity or lift heavy objects.
4. Women with pulmonary hypertension should avoid pregnancy.
5. Stop smoking.
6. Annual vaccination against influenza and pneumonia in people with chronic lung disease.
7. Avoidance of illicit drug use.
8. Control and treatment of essential hypertension.
9. Do not take drugs that inhibit appetite.