Cor pulmonale
Introduction
Introduction to pulmonary heart disease The most common chronic pulmonary heart disease is chronic hypoxic ischemic pulmonary heart disease, also known as obstructive emphysema heart disease, referred to as pulmonary heart disease, which is caused by chronic lesions of the lungs or pulmonary artery. Increased pulmonary circulation resistance, pulmonary hypertension and right ventricular hypertrophy, with or without right heart failure. Pulmonary heart disease is a common disease in China and is frequently ill. basic knowledge The proportion of illness: 0.003% Susceptible people: no special people Mode of infection: non-infectious Complications: pulmonary encephalopathy arrhythmia
Cause
Cause of pulmonary heart disease
Physiological factors (30%):
In chronic obstructive pulmonary disease, small airway obstruction leads to ventilatory disorders, as well as lung infection, pulmonary fibrosis and emphysema can destroy the blood gas barrier structure of the lungs, reduce the gas exchange area, and lead to ventilation dysfunction. Decreased partial pressure of alveolar oxygen (hypoxia), increased partial pressure of carbon dioxide, causing paralysis of pulmonary arterioles (hypoxia can interfere with potassium and sodium ion exchange in vascular smooth muscle cells and promote the release of vasoactive substances from mast cells, causing paralysis of pulmonary arterioles) .
Disease factor (30%):
Restrictive lung diseases, such as thoracic lesions, spinal curvature, pleural fibrosis, and thoracoplasty, can not only cause restrictive ventilatory disorders, but also oppress larger pulmonary vessels and cause distortion of pulmonary vessels, leading to increased resistance to pulmonary circulation. pulmonary hypertension. Pulmonary vascular diseases, such as repeated pulmonary embolism and primary pulmonary vascular disease, can also reduce pulmonary vascular bed area resulting in increased pulmonary circulation resistance and pulmonary hypertension.
Physical factors (30%):
Hypoxia can also lead to changes in the configuration of the pulmonary blood vessels, resulting in hypertrophy of the pulmonary arterioles and muscleless arterial arteries, resulting in increased pulmonary circulation resistance and pulmonary hypertension.
For increased pulmonary circulation resistance, smooth muscle differentiation of the pulmonary arterioles is enhanced, and adaptive hypertrophy of cardiomyocytes occurs in the right ventricle, but the adaptability of right ventricular myocytes is limited, when the right ventricular load is increased by 2 to 3.5 times. At the time, it is easy to expand the heart chamber. Therefore, pulmonary heart disease can be regarded as an adaptive response of pulmonary arterioles and right ventricle to pulmonary circulation resistance and pressure caused by chronic lung disease, and belongs to a special type of heart disease.
Pathological changes
1, lung lesions
In addition to the original chronic bronchitis, emphysema, pulmonary interstitial fibrosis and other diseases, the main pathological changes in the lungs are pulmonary arteriolar changes, which are characterized by mesenteric articular hypertrophy and submucosal appearance. Longitudinal muscle bundle, no muscle arteriolar muscle. Pulmonary arteritis, pulmonary arterial elastic fibers and collagen fibrosis, as well as pulmonary arterial thrombosis and mechanization can also occur. In addition, the number of capillaries in the alveolar wall is significantly reduced.
2, heart disease
Right ventricular hypertrophy, dilated heart chamber, dilated right ventricle increases the transverse diameter of the heart, and pushes the left ventricular apical region to the left rear to form a transverse heart. The apex is composed of the right ventricle. The apex is round and fat. Heart weight increases. The right ventricular anterior wall pulmonary artery cone is significantly bulging. The hypertrophic right ventricular papillary muscles and the meat column were significantly thickened, the supraventricular sac was thickened, and the myocardial wall was thickened in the pulmonary artery cone. The thickness of the right ventricular wall at 2 cm below the pulmonary valve is usually more than 5 mm (normally about 3 to 4 mm) as the pathological standard for pathological diagnosis of pulmonary heart disease. Under the microscope, it can be seen that the myocardial cells are hypertrophied, widened, and the nucleus is enlarged and stained deeply. It can also be seen that muscle fiber atrophy, sarcoplasmic dissolution, horizontal stripes disappear, and interstitial edema and collagen fibrosis are caused by hypoxia.
Prevention
Pulmonary heart disease prevention
Prevention common sense
1, pulmonary heart disease, the vast majority of chronic bronchitis, bronchial asthma complicated by emphysema, so active prevention and treatment of these diseases is a fundamental measure to avoid the occurrence of pulmonary heart disease.
2, should pay attention to health and enhance physical fitness, improve systemic resistance, reduce the occurrence of colds and various respiratory diseases.
Complication
Pulmonary heart disease complications Complications, pulmonary encephalopathy, arrhythmia
1. Pulmonary encephalopathy: a syndrome that causes mental disorders and neurological symptoms due to hypoxia and carbon dioxide retention caused by respiratory failure. However, it must be excluded from cerebral arteriosclerosis, severe electrolyte imbalance, simple alkalosis, and infectious toxic encephalopathy. It is the leading cause of death in pulmonary heart disease and should be actively prevented.
2. Acid-base imbalance and electrolyte imbalance: When respiratory failure occurs in pulmonary heart disease, due to lack of oxygen and carbon dioxide retention, various types of acid-base imbalances and electrolytes can occur when the body is unable to maintain homeostasis while maximizing compensatory ability. Disorders worsen respiratory failure, heart failure, and arrhythmia. It is of great significance for both treatment and prognosis. It should be monitored and treated in a timely manner.
3, arrhythmia: more manifested as atrial premature beats and paroxysmal supraventricular tachycardia, of which the most characteristic of ventricular atrial tachycardia. There may also be atrial flutter and atrial fibrillation. In a small number of cases, ventricular fibrillation and cardiac arrest can occur due to acute severe myocardial hypoxia. Should pay attention to the identification of arrhythmia caused by digitalis poisoning.
4, shock: Pulmonary heart disease shock is rare, once it occurs, the prognosis is poor. The causes are: 1 infection toxic shock; 2 hemorrhagic shock, mostly caused by upper gastrointestinal bleeding; 3 cardiogenic shock, severe heart failure or arrhythmia.
5, gastrointestinal bleeding.
6, diffuse intravascular coagulation (DIC).
Symptom
Symptoms of pulmonary heart disease Common symptoms Arrhythmia, convulsions, wheezing, heart function, decompensation, flapping tremor, dyspnea, menstruation, delayed oliguria
(1) Functional compensation period
Patients have a history of chronic cough, cough, or asthma, with progressive fatigue and difficulty breathing. Physical examination showed obvious emphysema manifestations, including barrel chest, lung percussion showed excessive unvoiced sound, liver dullness upper bound decreased, heart dull tone narrowed, and even disappeared. The auscultation sound is low, there may be dry and wet rales, the heart sound is light, and sometimes it can only be heard under the xiphoid. The second sound of the pulmonary artery is hyperthyroidized, and there is a significant heart beat under the upper abdomen xiphoid process, which is the main manifestation of the disease involving the heart. The jugular vein may have mild anger, but the venous pressure is not significantly increased.
(ii) Functional decompensation
Lung tissue damage causes severe hypoxia, carbon dioxide retention, which can lead to respiratory and/or heart failure.
1. Respiratory failure: The early manifestations of hypoxia are mainly purpura, palpitations and chest tightness. When the lesion develops further, hypoxemia and hypercapnia occur, and various symptoms of mental disorders may occur, which is called pulmonary encephalopathy. It is characterized by headache, head swelling, irritability, language barriers, and hallucinations, confusion, convulsions or tremors. When the arterial oxygen partial pressure is lower than 3.3 kPa (25 mmHg), when the arterial blood carbon dioxide partial pressure exceeds 9.3 kPa (70 mmHg), the central nervous system symptoms are more obvious, and there is a sense of indifference and lethargy, which leads to coma and death.
2. Heart failure: Most occur after acute respiratory infection, so often combined with respiratory failure, patients with asthma, palpitations, oliguria, increased purpura, upper abdominal pain, loss of appetite, nausea and even vomiting and other symptoms of right heart failure. Physical examination showed jugular vein engorgement, increased heart rate, systolic murmur caused by relative tricuspid regurgitation, and murmur disappeared as the condition improved. A variety of arrhythmia can occur, especially atrial arrhythmia, hepatomegaly with tenderness, positive liver and neck hydraulic signs, edema and ascites, severe cases can occur in shock.
In addition, since pulmonary heart disease is a disease in which multiple organs are damaged based on heart and lung lesions, in severe cases, renal insufficiency, disseminated intravascular coagulation, adrenal insufficiency, cheek hyperpigmentation, etc. may be present. which performed.
Examine
Pulmonary heart disease examination
Auxiliary inspection
(a) blood test
Red blood cell count and hemoglobin are often increased, hematocrit is normal or high, whole blood viscosity, plasma viscosity and platelet aggregation rate are often increased, red blood cell electrophoresis time is prolonged, erythrocyte sedimentation rate is generally faster; arterial oxygen saturation is often lower than normal, carbon dioxide The pressure is higher than normal, and the respiratory failure is more pronounced. In the heart failure period, there may be alanine aminotransferase and plasma urea nitrogen, creatinine, blood and urine 2 microglobulin (2-M), plasma renin activity (PRA), plasma angiotensin II, etc. Impaired liver and kidney function. When combined with respiratory infections, there may be an increase in white blood cell count. High potassium, low sodium, low potassium or low chlorine, low calcium, low magnesium and other changes may occur in different stages of respiratory failure.
(2) Bacterial culture
Streptococcus aureus, influenza bacillus, pneumococcus, staphylococcus, Neisseria, and Streptococcus viridans are more common. In recent years, Gram-negative bacilli have increased, such as Pseudomonas aeruginosa and Escherichia coli.
(3) X-ray examination
1 lung changes: with the disease, emphysema is the most common. 2 pulmonary hypertension showed: the total dry arc of the pulmonary artery was prominent, the pulmonary artery was enlarged and the first branch of the pulmonary artery was enlarged. It is generally believed that the transverse diameter of the first lower branch of the right pulmonary artery is 15 mm, or the ratio of the transverse diameter of the right lower pulmonary artery to the transverse diameter of the trachea is 0.17, or the dynamic observation is wider than the original right lower pulmonary artery by more than 2 mm. When the pulmonary hypertension is significant, the central pulmonary artery is dilated, the pulsation is enhanced, and the peripheral arteries are suddenly thinned to be truncated or rat tail. 3 heart changes: the heart is vertical, so the early heart does not increase. When the right ventricular outflow tract is enlarged, it appears that the conus of the pulmonary artery is significantly convex. After that, the right ventricular inflow tract is also enlarged and the apex is upturned. Sometimes the right atrium is enlarged. Heart failure can be extended with heart, but after heart failure control, the heart can return to its original size. The left heart is generally small, and occasionally the left ventricle is enlarged.
(4) Heart vector diagram check
Mainly manifested as right ventricular hypertrophy and/or right atrial enlargement, with the degree of right ventricular hypertrophy aggravated, QRS orientation gradually evolved from normal left lower front or back to backward, then downward, finally turned to the right front, but the end Still on the right back. The QRS ring runs from the counterclockwise to the motion or the 8-shaped to the clockwise operation. The P-ring is narrow, the amplitude of the P-ring on the left side and the forehead surface increases, and the maximum vector moves forward, left or right. In general, the more obvious the right atrial hypertrophy, the more the P-ring vector is to the right.
(5) Pulmonary function test
This test should not be performed during cardiopulmonary failure, and may be considered during the symptom remission period. Patients have ventilatory and ventilation dysfunction. It is characterized by decreased time lung capacity and maximum ventilation, and increased residual capacity. Injecting radionuclide 133 with four-probe function meter and gamma photographic and intravenous bolus injection method to determine the half-clearing time of the two lungs in the upper and lower fields can reflect the local ventilation function, and the detection rate of pulmonary heart disease is higher than that of general pulmonary function.
(6) Right heart catheterization
The pulmonary artery and right ventricular pressure can be directly measured by intravenously feeding the floating catheter to the pulmonary artery, which can be used as an early diagnosis of pulmonary heart disease.
In addition, the examination of pulmonary impedance blood flow map and its differential map can reflect the change of pulmonary blood flow volume in the body to some extent, understand the hemodynamic changes of pulmonary circulation, pulmonary artery pressure and right heart function; nuclear angiography can help To understand the changes of right ventricular function; pulmonary perfusion scan, such as increased blood flow in the upper part of the lung, lower in the lower part, suggesting the presence of pulmonary hypertension.
Diagnosis
Diagnosis and diagnosis of pulmonary heart disease
diagnosis
1. There are chronic bronchitis, emphysema and other diseases that cause structural or functional damage to the lungs leading to pulmonary hypertension and right heart hypertrophy.
2. Chronic cough, sputum symptoms and signs of emphysema, enhanced systolic pulsation under the xiphoid process and/or obvious enhancement of systolic murmur in the tricuspid valve area, and obvious second heart sound in the pulmonary valve area ( Cardiopulmonary function compensation period). Symptoms such as palpitations, shortness of breath and cyanosis and symptoms of right ventricular dysfunction (cardiopulmonary decompensation) occur after acute respiratory infection or more severe activity.
3. Chest X-ray diagnosis
(1) Diffusion of the right lower pulmonary artery: transverse diameter >= 1.5 cm. After dynamic observation, the transverse diameter of the arterial trunk was increased by more than 2 mm.
(2) The pulmonary artery segment protrudes with a height >= 3 mm.
(3) The central pulmonary artery dilatation is in sharp contrast with the peripheral branch slenderness, and it is "residual root".
(4) The convex height of the conical portion of the right front oblique position is >= 7 mm.
(5) Right ventricular enlargement (combined with different body positions). Those with more than two or (5) of items (1) to (4) can be diagnosed.
Differential diagnosis
1. Coronary heart disease: This disease and coronary heart disease are seen in elderly patients, and heart enlargement, arrhythmia and heart failure can occur. A few patients have Q waves on the electrocardiogram I, aVL or chest lead, similar to old myocardial infarction. However, pulmonary heart disease has no typical clinical manifestations of heart disease or myocardial infarction, and there are chronic bronchitis, asthma, emphysema and other history of chest and lung diseases, ST-T changes in ECG are not obvious, and similar to old myocardial infarction Most of the patterns occur in acute exacerbations of pulmonary heart disease and in apparent right heart failure, and these patterns can quickly disappear as the condition improves.
2. Rheumatic heart disease: Patients with pulmonary heart disease can smear and squeezing murmur in the tricuspid valve area, sometimes to the apex; sometimes a pulmonary-like diastolic murmur of pulmonary insufficiency: plus right heart hypertrophy, pulmonary artery High pressure and other performance, easy to be confused with rheumatic heart valve disease. Generally, through detailed inquiry about the history of chronic lung and chest diseases, signs of emphysema and right ventricular hypertrophy, combined with X-ray, electrocardiogram, heart vector map, echocardiography, etc., arterial oxygen saturation is significantly reduced, carbon dioxide The pressure is higher than normal and can be identified.
3. Primary dilated cardiomyopathy, constrictive pericarditis: the former heart is often spherical, often accompanied by heart failure, atrioventricular valve relative closure caused by murmur. The latter has heart palpitations, shortness of breath, cyanosis, jugular vein engorgement, hepatomegaly, ascites, edema, and low voltage of electrocardiogram, all of which need to be differentiated from pulmonary heart disease. Generally, it is not difficult to identify by medical history, X-ray, electrocardiogram, etc. In addition, the purpura has obvious thoracic deformity, and it needs to be differentiated from various purpuric congenital heart diseases. The latter has characteristic murmurs, and the clubbing is more obvious without pulmonary edema. It is generally difficult to identify.
4. Other coma: This disease has pulmonary encephalopathy coma fashion needs to be differentiated from hepatic coma, uremia coma and a few brain-occupying lesions or cerebrovascular accident coma. Such coma generally has the clinical features of its primary disease and is not difficult to identify.
