OVERVIEW
Pulmonary hypertension (PH) is a pathophysiological state of abnormally elevated pulmonary artery pressure due to a variety of known or unknown causes, characterized by progressive elevation of pulmonary vascular resistance, with hemodynamic diagnosis based on a mean pulmonary artery pressure of 25 mm Hg measured by right heart catheterization.PH can exist as a stand-alone disease, but is more commonly seen in the pathophysiological manifestations of a certain disease at a certain stage of its development. PH can exist as an independent disease, and is more often seen in the development of a disease to a certain stage of pathophysiological manifestations. Pulmonary hypertension due to multiple mechanisms is a complex mechanism of pulmonary hypertension caused by multiple diseases.
Etiology
The causes of pulmonary hypertension due to multiple mechanisms are varied and can be seen in the following diseases.
1. Blood system diseases
Myeloproliferative diseases and splenectomy.
2. Systemic diseases
Tuberculosis, pulmonary Langerhans cell histiocytosis, lymphangioleiomyomatosis, neurofibroma, vasculitis.
3. Metabolic diseases
Glycogen storage disease, Gaucher disease.
4.Others
Tumor obstruction, fibrous mediastinitis, dialysis treatment for chronic renal failure.
Symptoms
Symptoms of all types of PH are cool and non-specific, common manifestations are as follows.
1. Shortness of breath is the most common clinical manifestation, also known as shortness of breath and dyspnea, which is a manifestation of right heart insufficiency. Severe patients may have left heart failure manifestations such as high pillow position and sitting breathing.
2. About 1/3 of patients have chest pain.
3. Dizziness or fainting may occur during activities, which is more common in children.
4. Chronic fatigue is also one of the common symptoms.
5. Edema of ankles and legs, loss of appetite, hepatic bruising, pleural effusion or ascites.
6. Depression is also not uncommon in patients with PH.
7. Dry cough is also common, and sometimes blood can be seen in the sputum.
8. Fingers turn purple when exposed to cold, and cyanosis of lips and mouth, alopecia, irregular menstruation may also occur.
Examination
1. Physical examination
Pay attention to the signs of emphysema, hyperactive second heart sound in pulmonary valve area, enlargement of right heart and right heart insufficiency.
2. Electrocardiogram
Indirectly reflect pulmonary hypertension by suggesting enlargement or hypertrophy of the right heart, rightward deviation of the abnormal electrical axis, and low voltage in the limb leads.
3. Chest X-ray
It can show the characteristics of pulmonary hypertension. Pulmonary hypertension can be diagnosed if one of the following five items is present.
(1) Expansion of the right lower pulmonary artery trunk (transverse diameter ≥15mm), the transverse diameter of the right lower pulmonary artery trunk/transverse diameter of the trachea ≥1.07, or more than 2mm wider than the original right lower pulmonary artery trunk by dynamic observation.
(2) Significant protrusion of the pulmonary artery segment or a height of ≥3 mm.
(3) The central artery is dilated and the peripheral vasculature is slender, in sharp contrast to each other.
(4) Significant protrusion of the conical part of the pulmonary artery or a cone height of ≥7 mm.
(5) Enlargement of the right ventricle (in combination with different positions).
4. Blood tests
Including liver and kidney function tests, the significance of checking liver and kidney function is to properly manage possible liver and kidney complications caused by pulmonary hypertension. Blood tests also include human immunodeficiency virus (HIV) antibody tests and serologic tests to rule out cirrhosis, HIV infection, and occult connective tissue disease.
5. Echocardiography
Measurement of heart size, cardiac function, pulmonary artery internal diameter and pulmonary artery pressure is an important non-invasive tool in the diagnosis of pulmonary hypertension nowadays.
6. Lung function measurement
It is mainly used to determine the degree of ventilatory dysfunction. Mild restrictive ventilatory dysfunction with reduced diffusion function can be measured, and increased residual air volume and decreased maximal ventilation are seen in some severely ill patients.
7. Blood Gas Analysis
Respiratory alkalosis is present in almost all patients with pulmonary hypertension. The partial pressure of oxygen may be normal in the early stages, and most patients have mild to moderate hypoxemia due to an imbalance in the ventilation/blood flow ratio. Moderate hypoxemia may be related to decreased cardiac output, combined pulmonary artery thrombosis, or patent foramen ovale.
8. Radionuclide lung ventilation/perfusion scanning
Radionuclide pulmonary ventilation/perfusion scan is an important means to exclude chronic embolic pulmonary hypertension and can be used as a reference for the diagnosis of pulmonary hypertension.
9. Right heart catheterization
According to the hemodynamic parameters to determine the treatment plan and evaluate the clinical effect of drugs. Right heart catheterization is the only method that can accurately determine the hemodynamic status of the pulmonary vasculature.
Diagnosis
There is a clear relationship between the time of the first diagnosis of PH and the prognosis, so it is necessary to ask a detailed medical history, family history, and make a corresponding diagnosis based on laboratory tests and other auxiliary tests.
Treatment
Improvement of lifestyle, regular life, reasonable diet; drug therapy, interventional therapy, surgical treatment.