【Introduction to the disease
During the period of human embryonic development (within the first 2-3 months of pregnancy), the heart with local anatomical abnormalities caused by the formation disorders of the heart and large blood vessels, or the failure to close the channels that should close automatically after birth (which is normal in the fetus), is called congenital heart disease. Except for small ventricular septal defects that have a chance to heal spontaneously before the age of 5 years, the vast majority require surgical treatment. The main clinical manifestations are cardiac insufficiency, cyanosis, and dysplasia.
Congenital heart disease is a cardiovascular malformation caused by abnormal development of the heart vessels during fetal life, and is the most common heart disease in children. Its incidence is about 0.8% of births, and 60% of them die at the age of <1 year. The onset of the disease may be related to genetics, especially chromosomal translocations and aberrations, intrauterine infections, high-dose radiation exposure and drugs. With the rapid development of cardiovascular medicine, many common congenital heart diseases have been accurately diagnosed and reasonably treated, and the morbidity and mortality rates have decreased significantly.
Classification
Atrial septal defect (ASD), ventricular septal defect (VSD), patent ductus arteriosus (PDA), pulmonary valve stenosis (PS), tetralogy of Fallot (TOF), transposition of the great arteries (TGA)
[Etiology and pathogenesis
Heart disease is the result of the interaction of complex relationships such as genetic and environmental factors. The following factors may affect fetal development and produce congenital malformations.
1. Environmental factors of fetal development:
(1) Infections, viral or bacterial infections in the first trimester of pregnancy, especially rubella virus, followed by coxsackievirus, have a higher incidence of congenital heart disease in infants born with them.
(2) Other: such as amniotic membrane lesions, fetal compression, early pregnancy pre-eclampsia, maternal malnutrition, diabetes, phenylketonuria, hypercalcemia, the application of radiation and cytotoxic drugs in early pregnancy, the mother’s excessive age, etc. all have the potential to cause congenital heart disease in the fetus.
2. Genetic factors: congenital heart disease has a tendency to develop in families to some extent, which may be caused by parental germ cells and chromosomal aberrations. Genetic studies have concluded that most congenital heart disease is formed by the interaction of multiple genes and environmental factors.
3. other: some congenital heart diseases are more frequent in highland areas, and some congenital heart diseases have significant differences in incidence between male and female sexes, indicating that altitude and sex of birthplace are also related to the occurrence of this disease. Among patients with congenital heart disease, those who can find out the cause are very few, but strengthening health care for pregnant women, especially actively preventing rubella, influenza and other rubella viral diseases and avoiding all factors related to the onset of the disease in early pregnancy, is of positive significance to prevent congenital heart disease.
【Symptoms
1. Heart failure: Neonatal heart failure is considered an emergency, usually mostly due to the fact that the affected child has a more severe heart defect. Its clinical manifestations are due to congestion of the pulmonary and body circulations and a decrease in cardiac output. The child is pale, breath-holding, dyspnea and tachycardia, with a heart rate of up to 160-190 beats per minute, and blood pressure is often low. A galloping horse rhythm may be heard. The liver is large, but peripheral edema is less common.
2. Cyanosis: It arises from mixing of arterial and venous blood due to right-to-left shunt. It is most obvious in the tip of the nose, lips of the mouth, and nail beds of the fingers (toes).
Squatting: Children with cyanotic congenital heart disease, especially those with tetralogy of Fallot, often show signs of squatting after activity, which increases the vascular resistance of the body circulation and thus reduces the right-to-left shunt produced by the septal defect, and also increases venous blood flow back to the right heart, thus improving pulmonary blood flow.
4, pestle finger (toe) and erythrocytosis: cyanotic congenital heart disease is almost always accompanied by pestle finger (toe) and erythrocytosis. The mechanism of pestle finger (toe) is not clear, but erythrocytosis is a physiological response of the body to arterial hypoxia.
5. Pulmonary hypertension: When a patient with septal defect or arteriovenous catheterization develops a syndrome of severe pulmonary hypertension and cyanosis, it is called Eisenmenger’s syndrome. The clinical manifestations are cyanosis, erythrocytosis, pestle finger (toe), signs of right heart failure such as jugular vein anger, hepatomegaly, peripheral tissue edema, when the patient has lost the chance of surgery, the only waiting is heart and lung transplantation. Most of the patients die before the age of 40.
6.Disorders: Children with congenital heart disease tend to develop abnormally, manifesting as thinness, malnutrition, growth retardation, etc.
7.Other: chest pain, syncope, sudden death.
Diagnosis
Determining whether a child has congenital heart disease can be based on medical history, symptoms, signs and some special examinations to make a comprehensive judgment.
1. Medical history
(1) Pregnancy history of the mother: any viral infection in the first 3 months of pregnancy, radiation exposure, history of medication, history of diabetes mellitus, nutritional disorders, environmental and genetic factors, etc.
(2) Common symptoms: shortness of breath, cyanosis, especially pay attention to the age and time of cyanosis, whether it is related to crying and movement, whether it is paroxysmal or continuous. Symptoms of heart failure: increased heart rate (up to 180 beats/min), shortness of breath (50 to 100 breaths/min), irritability, pauses during feeding due to dyspnea and asthma-like attacks, etc. Recurrent or persistent upper respiratory tract infections, pallor, low crying, moaning, hoarseness, etc., also suggest the possibility of congenital heart disease.
(3) Development: Children with congenital heart disease are often malnourished, with thin bodies, no weight gain, delayed growth, etc., and may have squatting.
2. Physical examination
If physical examination reveals typical organic heart murmur, low heart sound, enlarged heart, arrhythmia and large liver, further examination should be performed to exclude congenital heart disease.
3. Special examination
(1) X-ray examination: there may be increased or decreased lung texture and enlarged heart. However, normal lung texture and normal heart size do not exclude congenital heart disease.
(2)Color Doppler ultrasonography: quantitative measurement of the size of the chambers and blood vessels of the heart is used to diagnose the anatomical abnormalities of the heart and their severity, which is one of the most common diagnostic methods for congenital heart disease.
(3) Electrocardiography: It can reflect the position of the heart, the presence of hypertrophy in the atria and ventricles, and the condition of the cardiac conduction system.
(4) Cardiac catheterization: It is one of the important examination methods for further definite diagnosis of congenital heart disease and before deciding to operate. Through catheterization, we can understand the blood oxygen content and pressure changes in different parts of the heart chambers and large blood vessels, and clarify the presence or absence of shunts and the parts of shunts. To understand the development of the pulmonary arteries in tetralogy of Fallot. To understand the presence or absence of severe pulmonary hypertension, to determine the size of pulmonary resistance and to guide the timing of surgery.
(5) Cardiovascular imaging: For patients whose diagnosis is still not clear through catheterization and who need to consider surgical treatment, cardiovascular imaging can be performed. The iodine-containing contrast agent is rapidly injected into the heart or large blood vessels through the cardiac catheter under mechanical high pressure, and continuous rapid film or movie is taken to observe the shape, size and location of the atria, ventricles and large blood vessels as shown by the contrast agent, as well as the presence of abnormal channels or stenosis or atresia.
(6) Determination of pigment dilution curve: Various dyes (such as Evans blue, US blue, etc.) are injected into different parts of the circulatory system through the cardiac catheter, and then the changes in the concentration curve formed by the dilution process of the indicator in the arterial or venous blood are measured, and the direction and location of the shunt can be judged according to the changes in this curve, and the cardiac blood volume and pulmonary blood volume can be further calculated.
Based on the positive signs from the above history, physical examination and special examination, a comprehensive analysis and judgment can be made to clarify the diagnosis of congenital heart disease.
[Prevention].
(1) Although the cause of congenital heart disease is not very clear, in order to prevent the occurrence of congenital heart disease, attention should be paid to the mother’s health care during pregnancy, especially in early pregnancy, such as active prevention of rubella, influenza, mumps and other viral infections. Avoid exposure to radiation and some harmful substances. Use medications under the guidance of doctors and avoid taking drugs that have an impact on fetal development, such as anti-cancer drugs and methylglyoxal. Actively treat primary diseases, such as diabetes. Pay attention to reasonable diet and avoid nutritional deficiency. Prevent local mechanical compression around the fetus. In short, in order to prevent congenital heart disease, all factors related to its development should be avoided.
(2) In early pregnancy (before 3 months) try not to sit too long in front of the computer microwave oven and other places with strong magnetic fields because the fetus is still unstable at this time and all organs are still in the forming stage which may cause congenital heart disease in the child.
(3) Do not touch pets because the bacteria and microorganisms on pets may also cause congenital heart disease in children.
Genetics]
The incidence of congenital heart disease in children is about 4‰ to 8‰, which can be a common congenital disease. With the improvement of medical level, many children with congenital heart disease live well after surgical treatment and grow up to have a family.
However, all people with congenital heart disease want to have a healthy child when they are parents themselves, and the best way to do this is to go to a hospital for premarital screening and genetic counseling before marriage.
Because congenital heart disease is a polygenic genetic disease, it is now recognized that congenital heart disease can be caused by environmental factors and genetic factors or both together, especially the latter is important, and about 90% of congenital heart disease is caused by the combination of genetic plus environmental interaction. Many people think that people with congenital heart disease are the same as normal people after surgery and there is no danger of having children, this view is very incomplete, they only pay attention to the tolerance of the heart and ignore the hereditary nature of the disease. Therefore, to fully understand the impact of congenital heart disease on marriage and childbirth, you can go to a designated premarital examination unit, or you can go to a cardiology specialist for a checkup, such as a color ultrasound of the heart, and according to the type of your heart disease. Listen to your doctor’s advice and have genetic counseling.
Complications
I. Pneumonia
Heart failure
Pulmonary hypertension
IV. Infective endocarditis
V. Hypoxic attack
Cerebral thrombosis and brain abscess
Treatment methods
There are two types of congenital heart disease treatment methods: surgery and interventional therapy
(1) Surgical treatment is the main treatment modality, which is practical for all kinds of simple congenital heart disease (such as: ventricular septal defect, atrial septal defect, arteriovenous ductus arteriosus, etc.) and complex congenital heart disease (such as: combined pulmonary hypertension, tetralogy of Fallot and other heart diseases with cyanosis).
Interventional therapy is a new treatment method developed in recent years, mainly for children with unclosed ductus arteriosus, atrial septal defect and partial ventricular septal defect that are not combined with other anomalies requiring surgical correction. The difference between the two mainly lies in the fact that surgical treatment has a wider scope of application and can cure all kinds of simple and complex congenital heart diseases, but there is a certain degree of trauma, longer recovery time after surgery, a few patients may have arrhythmias, chest and heart cavity effusion and other complications, and also leave surgical scars affecting the aesthetics. Interventional treatment is narrower in scope and more expensive, but it is non-invasive, with a quick recovery and no surgical scars.
During the treatment, the doctor punctures the patient’s blood vessel (usually using the blood vessel at the root of the thigh) and delivers an appropriately sized blocker to the lesion to block the defective or unclosed arterial duct through a specially designed sheath of 2-4 mm in diameter, under the guidance of X-ray and ultrasound, in order to achieve the purpose of treatment. Through clinical practice, it is confirmed that interventional occlusion of precordial disease has the advantages of small trauma, short operation time (about 1 hour), quick recovery (can be out of bed the next day after operation), no special anesthesia and extracorporeal circulation, and short hospitalization period (about 1 week). General anesthesia is required only if the patient is too young to cooperate with the operation. The indications for this procedure are very broad, and atrial septal defects, patent ductus arteriosus, and ventricular septal defects can all be treated with interventional methods. Interventional treatment of congenital heart disease also has its limitations and is not suitable for those with existing right-to-left shunts, severe pulmonary hypertension, combined malformations that require surgical correction, or large defects with poor margins.
About the interventional treatment of congenital heart disease
Interventional treatment of congenital heart disease has come a long way since Portmann used foam to seal congenital ductus arteriosus in 1967. With the increase of cases and the accumulation of experience, the operation technique has become more and more mature, and it has become a routine method for the treatment of congenital heart disease in large medical units. Nearly 50 hospitals in China perform such procedures.
Patent ductus arteriosus (PDA)
At present, more than 2,500 cases of PDA have been completed in China using imported Ampatzer blockers, with a technical success rate of 98.4%. The rate of serious complications is 1.6% (including 1.36% hemolysis, 0.2% dislodgement of the occluder and 0.04% pericardial tamponade), and the mortality rate is only 0.04%.
Atrial septal defect (ASD)
At present, more than 3,500 cases of atrial septal defect blocking have been treated with imported Ampatzer blockers in China, with a technical success rate of 98.1%. The rate of serious complications is 0.9% (including 0.5% of blocker dislodgement and 0.4% of pericardial blockage), and the mortality rate is only 0.2%.
Ventricular septal defect (VSD)
In 2002, AGA developed a new type of self-expanding asymmetric double-disc septal defect sealer, which has been clinically applied at home and abroad for nearly one year and achieved satisfactory results.
At present, more than 250 cases of ventricular septal defect sealing have been completed in China with a success rate of 97.3% using this technology. Due to the high technical requirements, complicated operation and lack of experience in the initial development, the complication rate is relatively high, reaching 2.7%, mainly including blocker dislodgement, hemolysis, atrioventricular block, aortic valve or tricuspid valve insufficiency. Therefore, this technique should not be performed blindly by physicians who have not undergone rigorous training and by hospitals that do not have adequate technical skills.
Prospects
With the continuous improvement of interventional equipment, the accumulation of interventional experience and the improvement of operation technology, the scope of interventional treatment of congenital heart disease will be increasingly expanded, such as the interventional treatment of compound malformation of congenital heart disease, the interventional treatment of residual shunt or residual stenosis after surgery, and the combined treatment of complex congenital heart disease by interventional technology and surgery.
It is undeniable that there are still some congenital heart diseases that cannot be treated by interventional techniques, therefore, before treatment, a comprehensive examination should be conducted to strictly distinguish the indications for interventional and surgical treatment, weigh the advantages and disadvantages, and formulate the best plan that is reasonable and feasible.
Interventional treatment of precardiac disease has the following advantages compared to surgical procedures.
1. no incision on the chest and back is required, and only a needle eye (about 3 mm) is left in the groin. It is less traumatic and less painful, and heals within a few days after surgery without leaving scars; there is also no need to open the chest cavity, much less cut open the heart.
2. The treatment does not require the implementation of systemic external circulation and deep hypothermia anesthesia. Children only need basic anesthesia without intubation to cooperate, and older children only need local anesthesia. In this way, extracorporeal circulation and anesthesia accidents can be avoided, and there is no impact on the brain development of children.
3. Because of the low bleeding of interventional treatment, no blood transfusion is required, thus avoiding the possible adverse effects caused by blood transfusion.
4. Compared with surgical procedures, interventional treatment has a shorter operation time, shorter hospital stay and faster postoperative recovery. Usually, drinking starts in about 30 minutes to 1 hour, and children can be out of bed in 20 hours after the procedure, and can be discharged in 1-3 days of hospitalization, which can be done on an outpatient basis for children with local anesthesia.
5. At present, the success rate of various interventional treatments for children suitable for interventional treatment is over 98%, and the postoperative complications are less than those of surgical procedures. It is like surgery and can have a radical effect.
6.Hybrid surgery: surgery + intervention
【Best time for treatment】.
The best treatment time for surgery depends on a variety of factors, including the complexity of the congenital malformation, the age and weight of the child, the general development and nutritional status, etc. Generally, for simple congenital heart, it is recommended to be 1 – 5 years old, because too young, low weight, poor systemic development and nutritional status will increase the risk of surgery; too old, the heart will compensate for the increase in size, and some may even have increased pulmonary artery pressure, which will also increase the difficulty of surgery and longer recovery time after surgery. For combined pulmonary hypertension, congenital malformations that are serious and affect growth and development, malformations that threaten the life of the child, and complex malformations that require staged surgery, the earlier the surgery the better, regardless of age.
Healing is possible]
Congenital heart disease generally cannot heal on its own, and requires surgery or interventional methods to cure. However, for ventricular or atrial defects with a caliber of less than 0.5 cm, no treatment is needed, as it will not adversely affect the heart function and growth of the child. However, due to the presence of heart murmur, which has certain impact on future education, employment and marriage, and the surgery is now very mature, some parents still choose surgery due to these social factors. There are also some small defects, such as ventricular defects in the sub-stem area, which are less than 0.5 cm due to their proximity to the aortic valve, and they also require active surgical treatment. For children with defects larger than 0.5 cm in caliber, surgery is recommended.
Postoperative care]
Ventilator cooperation: cardiac surgery patients are usually put on the ventilator, pay attention to the depth of the tracheal intubation, often listen to the normal symmetry of the breath sounds of both lungs, and take bedside X-rays if necessary to understand the position of the tracheal intubation. After waking up from anesthesia, the patient will feel uncomfortable in the throat and cannot speak, and the patient needs to cooperate actively. Do not turn the head too much and do not swallow at will, especially for infants and children repeated rubbing of the respiratory mucosa can cause bleeding of the vocal cords, and for uncooperative children, sedation can be given. If there is a need, such as bowel movements, urination, sputum production, etc., use sign language to tell the nurse. To prevent intrapulmonary infection, nurses should give endotracheal suction to ventilated patients regularly. There will be shortness of breath, pain and other uncomfortable sensations, so bear with it.
Cooperation after removal of air intubation: The condition is smoothly disconnected from the ventilator, and oxygen is continued by mask or nasal cannula. The patient should remain quiet at this time. The patient should actively cooperate when effective postoperative sputum production is an important part of preventing complications such as intrapulmonary infection or pulmonary atelectasis. If the patient is in pain and does not dare to sputum, painkillers can be given. It is important to keep the airway open to prevent greater pain caused by intrapulmonary infection or pulmonary atelectasis.
[Home care].
Try to keep the child quiet, avoid excessive crying, and ensure sufficient sleep. Older children should have a regular life, combining movement and stillness, neither running around outside (running and jumping and strenuous exercise are strictly prohibited), nor do they need to lie in bed all day, and sleep must be guaranteed at night to reduce the burden on the heart.
Children with cardiac insufficiency tend to sweat more, so they need to keep their skin clean, bathe regularly in summer, rub themselves with hot towels in winter (pay attention to keeping warm), and change their clothes and pants regularly. Feed more water to ensure adequate hydration.
Keep the stool smooth, if the stool is dry and difficult to defecate, excessive force will increase the abdominal pressure, increasing the burden on the heart, and may even have serious consequences.
Keep the air circulating in the room, and avoid staying in crowded public places to reduce the chance of respiratory tract infection. Add and remove clothes in time with the weather and pay close attention to the prevention of colds.
Regular follow-up visits to the hospital cardiology clinic and strict compliance with medical prescriptions, especially for cardiac and diuretic drugs, due to their pharmacological properties, the dosage must be absolutely controlled and taken on time and according to the course of treatment to ensure efficacy. Before each dose of cardiac drugs, the pulse count must be measured, if the heart rate is too slow, should immediately stop taking, to prevent the occurrence of toxic effects of drugs, endangering the life of the child.
The prevention and treatment of congenital heart disease
Although the cause of congenital heart disease is not very clear, in order to prevent the occurrence of congenital heart disease, attention should be paid to the mother’s health care during pregnancy, especially in the early stages of pregnancy.
Such as:
Actively prevent rubella, influenza, mumps and other viral infections.
Avoid exposure to radiation and some harmful substances.
Use medications under the guidance of doctors and avoid taking drugs that have an impact on fetal development, such as anti-cancer drugs and methylglyoxal.
Actively treat primary diseases, such as diabetes.
Pay attention to reasonable diet and avoid nutritional deficiency.
Prevent local mechanical compression around the fetus.
In conclusion, in order to prevent congenital heart disease, all factors related to its development should be avoided.