Overview of arterial hypertension
Arterial pulmonary hypertension is a category of precapillary pulmonary hypertension in which the mean pulmonary artery pressure measured by right heart catheterization at rest is elevated (≥25 mmHg) and the pulmonary capillary wedge pressure is normal (≤15 mmHg). Arterial pulmonary hypertension is categorized as the first major group of pulmonary hypertension, which includes idiopathic pulmonary hypertension, hereditary pulmonary hypertension, drug- and toxin-induced pulmonary hypertension, disease-associated pulmonary hypertension, and persistent pulmonary hypertension of the newborn.
Etiology
The etiology of this disease is unknown and may be related to the following factors.
1. Drug factors
Including appetite suppressants fenfluramine, phentermine; central excitatory drugs amphetamine, methamphetamine and so on. The longer the duration of application, the greater the risk of pulmonary hypertension.
2. Viral infections
Human immunodeficiency virus (HIV) infection has been found to trigger arterial pulmonary hypertension, which is realized by inhibiting the potassium ion channels of smooth muscle cells in pulmonary hypertension and making them functionally defective. This is categorized as HIV-associated pulmonary hypertension.
3. Genetic factors
Closely related to genetic mutations, the identified causative genes include bone-forming protein receptor-2 and activin receptor-like kinase.
Symptoms
In addition to the symptoms of exertional dyspnea, chest pain, syncope, and the signs of second heart sound, tricuspid regurgitant murmur, and even right heart insufficiency, patients with arterial pulmonary hypertension will also have the corresponding clinical manifestations of the underlying diseases, for example, connective tissue disease-associated pulmonary hypertension may have pteronyssinus erythematosus in cheeks, Raynaud’s phenomenon, and so on; patients with human immunodeficiency virus infection may have fever, hemorrhage, and opportunistic symptoms. Human immunodeficiency virus infection patients may have fever, bleeding, opportunistic infections, enlarged liver, spleen and lymph nodes; portal hypertension patients may have abdominal distension, vomiting blood, black stools, splenomegaly, jaundice, spider nevus, etc.; patients with congenital heart disease often have cyanosis, pestle finger and corresponding heart murmur; patients with schistosomiasis may have abdominal pain, anemia, vomiting blood, black stools, liver and spleen enlargement; patients with chronic hemolytic anemia may have anemia, jaundice and splenomegaly.
Examination
1. Electrocardiogram
There may be right deviation of electrical axis, pulmonary P wave, ST segment depression, shallow or inverted T wave, arrhythmia and other manifestations.
2. Chest X-ray
Chest X-ray may show thickening of the right lower pulmonary artery, or even dilatation of the central pulmonary artery and slenderness of the peripheral pulmonary vessels, and enlargement of the right atrium and right ventricle.
3. Echocardiography
Echocardiography can assess the cardiac function and morphological changes, and estimate the pulmonary artery pressure and right ventricular systolic pressure.
4. Pulmonary function tests and blood gas analysis
To detect potential airway or pulmonary disease.
5. Lung enhancement CT
It can find out whether there is sleep apnea syndrome causing pulmonary hypertension.
6. Pulmonary angiography
To rule out chronic thromboembolic pulmonary hypertension, pulmonary vasculitis and pulmonary arteriovenous malformation.
7. Hematologic examination
Including blood routine, liver function, immunology, thyroid function and pathogenic microorganisms.
Diagnosis
Diagnosis can be made if the average pulmonary artery pressure measured by right heart catheterization under resting state is ≥25mmHg, pulmonary capillary wedge pressure is ≤15mmHg, cardiac output is normal or reduced, and other causes of precapillary pulmonary hypertension are excluded.
Treatment
1. Treatment of primary disease
For patients with primary disease, the treatment of primary disease should be emphasized. Arterial pulmonary hypertension caused by drugs or poisons should stop using drugs or contacting poisons.
2. General treatment
Life guidance, including avoiding exertion, preventing respiratory infections, contraception for women of childbearing age, preventing anemia, and oxygen absorption. Appropriate psychological guidance should be given to enhance patients’ confidence in overcoming the disease.
3. Basic drug therapy
Anticoagulant drugs, diuretics, cardiac glycosides.
4. Surgical treatment
Lung transplantation or combined heart-lung transplantation.