The pulmonary hypertension primary is a rare disease characterized by increasing pressure in the pulmonary artery, with no known cause.
It predominantly affects women, with an incidence of two cases per million inhabitants. The age of onset is usually between thirty and forty years old, although it can appear at any age. The main symptom is the presence of dyspnea (shortness of breath), which appears progressively in people without other symptoms and without apparent cardiac or pulmonary problems. As the disease progresses, the rest of the clinical data and symptoms associated with pulmonary hypertension appear, so it is usually diagnosed in advanced stages.
The prognosis is poor, with a median survival, from diagnosis, of 3 to 5 years, although it varies depending on the degree of effort that the patient is able to carry out without the appearance of dyspnea (functional class). Patients with a very poor functional class (they are barely able to make minimal efforts) have very low survival rates (less than 6 months).
In addition, there is secondary pulmonary hypertension, characterized by high levels of pulmonary pressure as a consequence of cardiological or pulmonary diseases. In these cases, hypertension is one more complication, added to the underlying disease.
Causes of pulmonary hypertension
The cause of primary pulmonary hypertension is not known, however, it seems that there is an abnormality in the cells that line the arteries and the pulmonary capillaries inside them. Thus, there is an unknown triggering factor, which alters the function of these cells, reducing the control of the muscle tone of the vessels, which causes constriction of the arteries, activation of platelets and thus favors the formation of thrombi.
It is also possible that there is a genetic basis for the development of this disorder.
Familial primary pulmonary hypertension appears in 7% of cases. It usually appears at younger ages, with a greater intensity in the different successive generations. These patients show a genetic predisposition that manifests itself after exposure to an external triggering factor.
Secondary hypertension arises as a consequence of heart or lung disease. The most common are diseases of the mitral and aortic valves, hypertrophic and dilated cardiomyopathies, some congenital heart disorders, chronic obstructive pulmonary disease, pulmonary thromboembolism, and pulmonary interstitial diseases.
The right ventricle of the heart pushes blood into the pulmonary arteries, which carry it to the lungs, where it is oxygenated. This oxygenated blood returns through the pulmonary veins to the heart, specifically to the left atrium, from where it continues to the rest of the body.Heart affected by pulmonary hypertension
At the beginning of this disorder, there is an increase in resistance to blood flow through the pulmonary arteries (both in the primary and in the secondary), this increases the pressure in the pulmonary artery significantly, while the function of the ventricle Right of the heart remains stable, because it develops compensation mechanisms, such as: the increase in muscle mass, first, and then, the increase in volume. Over time, cardiac output decreases progressively, without the pulmonary artery pressure rising in parallel.
In advanced stages of the disease, the ventricle becomes insufficient to develop the necessary power for the flow to overcome the pressure of the pulmonary artery, and the pressure of the ventricle and the right atrium increases, thus developing right heart failure, which is the last step of the disease.
Symptoms of pulmonary hypertension
The main symptom is dyspnea (shortness of breath) that at first only appears with great efforts, but that progressively becomes more and more intense and with less effort, until reaching a point, in severely affected patients, in which dyspnea appears even at rest. Other symptoms are tiredness and fatigue, syncope, fainting spells, and angina pectoris, which almost always means ischemia (lack of oxygen in the tissues) of the right ventricle.
When patients develop right heart failure, they present its own symptoms, with engorgement of the jugular veins, edema in the lower extremities, liver congestion, and decreased pulse. The right ventricular beat is well palpable in these patients and they almost always develop third and fourth tones on auscultation. Sometimes tricuspid regurgitation or pulmonary regurgitation occurs.
How is it diagnosed?
An exhaustive study must be carried out to look for all possible causes and if none appear, the label of primary pulmonary hypertension can be put.
The tests to be carried out are the following:
- Arterial blood gas: It is an analysis that allows us to measure the pressure of oxygen and CO2 in arterial blood. Hypoxemia is common, accompanied by normal or decreased CO2 values.
- Chest X-ray: Shows an increase in the trunk of the pulmonary arteries without any alteration in the area of the lungs.
- EKG: Indicates deviation of the axis to the right and hypertrophy of the right ventricle.
- Echocardiogram : There is an increase in the right ventricle, with a decrease in the left and with an abnormality in the configuration of the septum, compatible with pressure overload of the right ventricle. If there is a cardiac alteration that leads to hypertension, this test will show us.
- Spirometry: Generally shows a mild restrictive pattern. If an obstructive pattern appears, it is necessary to think of hypertension secondary to pulmonary disease.
- Lung perfusion scan: It can be normal or abnormal. If it shows diffuse filling defects not suggestive of PTSD, it is probably due to hypertension. On the contrary, if the defect is segmental or subsegmental, angiography should be performed, which confirms or rules out PET.
- Cardiac catheterization : It is mandatory to perform it in all patients, as a definitive test. It allows us to measure the degree of hypertension of the patient, the presence or absence of cardiac malformations, the existence of left valve abnormalities or left ventricular hypertrophy.
The protocol to be followed is as follows: first a chest X-ray should be performed, if it shows pulmonary alterations it should be considered that there is an interstitial lung disease, responsible for the increase in pulmonary pressure. If the X-ray is normal, a spirometry must be performed, which can give an obstructive pattern, with which COPD will be the cause of hypertension, or a normal or restrictive pattern. Both can be seen in pulmonary hypertension, so a blood gas test must be performed. If CO2 is elevated, the diagnosis must be a hyperventilation syndrome; if, on the other hand, it is normal or low, a scintigraphy must be performed. When the scan shows irregular defects or is normal, An echocardiogram should be performed to rule out the presence of heart disease causing hypertension. If this test is normal, a cardiac catheterization must be performed to confirm the diagnosis of primary hypertension. If the scintigraphy shows segmental defects, a pulmonary angiogram should be performed to confirm or rule out the presence of PE; If this problem does not exist, an echocardiogram and cardiac catheterization will be necessary.
Treatment of pulmonary hypertension
First of all, we must recommend rest, since physical exercise increases pulmonary pressure. When heart failure develops, we must treat the patient with diuretics, which improve venous congestion.
Trials should be performed with short-acting pulmonary vasodilators, such as: inhaled nitric oxide, intravenous adenosine, and intravenous prostacyclin.
If with these drugs improvement is obtained due to a decrease in the resistance to flow of the pulmonary vessels, a treatment with oral calcium antagonists (nifedipine or diltiazem) can be started. This treatment is only effective in a small number of patients, but in these it manages to reduce pulmonary pressure, thereby improving the function of the right ventricle and prolonging survival. This treatment is most effective in patients diagnosed early and with a poorly advanced disease.
Other groups of vasodilators, such as beta-adrenergic agonists, alpha adrenergic blockers, nitrates, or angiotensin-converting enzyme inhibitors have not given the results that have been obtained with the previous ones.
Chronic intravenous prostacyclin treatment has recently been approved in patients with advanced degrees of hypertension and poor functional class. In these patients, it has been shown to improve symptoms, increase exercise tolerance, and reduce mortality. The downside is that it can only be administered intravenously, thus requiring an indwelling catheter in a vein to administer the medication, with the consequent risk of infection. This treatment is very complex since the dose must be continuously adjusted, so it must be handled in highly specialized centers.
These patients must be anticoagulated because they frequently develop thrombosis, so anticoagulation increases survival, although it does not correct the disease or improve symptoms.
Patients with very advanced hypertension and right ventricular impairment, with an estimated survival of less than one year, should undergo heart-lung or bilateral lung transplantation, which is also beneficial and less complicated than cardiopulmonary transplantation. Once transplanted, no case has been demonstrated in which primary hypertension reappears in the new lungs.
In cases of secondary pulmonary hypertension, treatment should be aimed at correcting the cause that produces it.
How can I avoid it?
Primary pulmonary hypertension is a disease of unknown cause, so there is nothing we can do to prevent its appearance by not knowing why it appears. Yes, we can act on the favorable causes, such as: arterial hypertension (exercise, eat without salt, avoid tobacco, carry out the appropriate treatment if prescribed).
To avoid the appearance of secondary hypertension, it is essential to control its causes; thus, some cardiac alterations are difficult to prevent, but others such as hypertrophic cardiomyopathy, secondary to arterial hypertension, could be avoided by controlling our blood pressure figures, with a healthy diet and moderate physical exercise. In all these cases, pulmonary hypertension develops in advanced stages of the disease, so we must complete the treatment prescribed in the most correct way, in order to avoid these complications.
Increased lung pressure also occurs as a consequence of lung diseases such as COPD, the main causative factor of which is tobacco. Abstention from smoking is one of the main objectives of current medicine, since tobacco is one of the main agents involved in the development of multiple diseases, so all smokers should try to give up this vice.
The presence of sustained dyspnea should always be a reason for medical consultation, since it can be due to a multitude of cardiological or pulmonary diseases, some of them very serious and that require early and energetic treatment. We should always consult when the first symptoms appear and not when the disease is very advanced with signs of heart failure, because the prognosis is much worse.
Hello Readers, I am Nikki Bella a Psychology student. I have always been concerned about human behavior and the mental processes that lead us to act and think the way we do. My collaboration as an editor in the psychology area of Well Being Pole has allowed me to investigate further and expand my knowledge in the field of mental health; I have also acquired great knowledge about physical health and well-being, two fundamental bases that are directly related and are part of all mental health.