Overview of the disease
Due to congenital dysplasia, the blood flow channel between the right ventricle and the pulmonary artery is narrowed. In mild cases, there are no symptoms, but in moderate to severe cases, there may be chest tightness, shortness of breath, palpitations and even fainting after activity. The main causes of congenital developmental anomalies are due to genetic, maternal and environmental factors, and are mostly treated with interventional and surgical treatments.
Definition
Pulmonary stenosis is the narrowing of the blood flow channel between the right ventricle and the pulmonary artery due to congenital dysplasia [1].
In mild cases, there are no obvious symptoms, and in middle and late stage patients, it is characterized by chest tightness, shortness of breath, palpitation and even fainting after activity, poor activity tolerance and easy fatigue.
Typing
According to the pathologic anatomy, stenosis can be divided into subvalvular stenosis, valvular stenosis and supravalvular stenosis.
Pathogenesis
Congenital simple pulmonary stenosis (without other congenital heart disease) accounts for about 10% of children with congenital heart disease, and congenital pulmonary stenosis is present in about 20% of congenital heart disease cases [2].
The incidence of congenital heart disease ranges from 6 to 10 per 100,000 live-born newborns [2].
Etiology
Causes of the disease
Pulmonary stenosis belongs to one of the congenital heart diseases, and the development of congenital heart disease is mainly related to genetic factors, maternal factors and environmental factors [2].
Genetic factors
It has been found that the genetic factors for the development of congenital heart disease mainly include single gene defects, polygenic defects, etc. Generally speaking, most of the congenital heart diseases are inherited from multiple genes [2].
Maternal factors
Maternal factors are mainly related to the infection of rubella, influenza, mumps and coxsackie viruses during pregnancy, or pregnant women suffering from diabetes mellitus, hypercalcemia, phenylketonuria and other diseases.
In addition, congenital heart disease may be triggered if the pregnant woman is deficient in folic acid or if the fetus has intrauterine hypoxia [2].
Environmental factors
Pregnant women who are exposed to radiation, organic chemicals, or take anticancer drugs or antiepileptic drugs during pregnancy may trigger congenital heart disease [2].
Pathogenesis
The human cardiovascular system is differentiated from the mesoderm of the embryo. Generally, the cardiovascular system begins to differentiate to form the primitive cardiovascular system after the 15th day of embryonic formation, and blood circulation begins after the 21st day of embryonic formation [3].
Under the influence of the aforementioned genetic, maternal, and environmental factors, abnormalities in the differentiation of the cardiovascular system may occur, leading to pulmonary stenosis [3].
Symptoms
Main Symptoms
Early stage
Early stage patients have mild or no symptoms.
Middle and late stage
Middle and late stage patients show chest tightness, shortness of breath, palpitations and even fainting after activities, poor activity tolerance and easy fatigue.
Symptoms worsen with age.
Other symptoms
Newborns with severe pulmonary stenosis may have cyanosis and hypoxia of the lips as well as the skin all over the body, and shortness of breath [4].
In advanced cases, patients may experience chest pain, syncope, and even the possibility of sudden death [4].
Complications
Right heart failure
is a late complication, which is mainly manifested as abdominal distension, lower limb edema, abdominal distension, lack of appetite, and even nausea, vomiting and other symptoms appear [5].
Consultation
Department of Medicine
Cardiovascular medicine
Patients with symptoms such as chest tightness, shortness of breath, palpitations or even fainting after activity, and poor activity tolerance need to seek medical treatment from the Department of Cardiovascular Medicine in a timely manner.
Cardiovascular Surgery
Patients diagnosed with pulmonary artery stenosis and needing surgical treatment should go to the Department of Cardiothoracic Surgery in a timely manner.
Emergency
Patients with symptoms such as severe dyspnea and syncope should go to the emergency room immediately.
Preparation
Consultation: registration, preparation of documents, common problems
Tips
Wear loose-fitting clothes that are easy to put on and take off on the day of your visit, so that you can be easily examined.
Do not wear jewelry before the visit.
Preparation Checklist
Symptom list
Pay particular attention to the time of onset of symptoms, special manifestations, etc.
When did the symptoms such as chest tightness, shortness of breath, palpitations or even fainting after activity, and poor activity tolerance start?
How long do they last?
How did the disease develop? Did the symptoms get progressively worse?
Medical history list
Any other history of heart disease?
Has there been any other medical condition?
Checklist
Test results from the last six months, which can be brought to the doctor’s office
Imaging tests: echocardiography, X-ray, ECG.
Laboratory tests: BNP test.
Medication list
Medication used in the last 3 months, if available in boxes or packages, you may bring them to the doctor
Sodium nitroprusside, nitroglycerin, etc.
Diagnosis
Diagnosis based on
medical history
Infants born to pregnant women with the presence of hypertension and diabetes during pregnancy; infants born to those with a history of rubella and influenza during pregnancy; history of exposure to radiation during pregnancy, etc. [2].
Clinical manifestations
Symptoms
Mild stenosis may remain asymptomatic for a long time.
Those with moderate to severe stenosis show chest tightness, shortness of breath, palpitations and even fainting after activities, poor activity tolerance and easy fatigue.
Symptoms aggravate with age, and right heart failure manifestations such as hepatomegaly, lower limb edema, and ascites appear in the late stage.
Physical signs
A loud wind-blowing systolic murmur with systolic tremor can be heard in the second intercostal space at the left edge of the sternum, and the second heart sound of the pulmonary artery is weakened or disappeared.
In funnel stenosis, the location of the murmur is usually in the 3rd to 4th intercostal space of the left sternal border.
In severe stenosis, the heart murmur is mild, and the lips and limbs are cyanotic.
Imaging
Echocardiography
Purpose of the examination: To determine the degree of anatomical location of the stenosis, to estimate the severity of pulmonary stenosis, and the presence of cardiac valve dysplasia.
Significance of the examination: If the right ventricle is enlarged in patients with pulmonary stenosis, the degree of pulmonary valve stenosis and valve dysplasia can be seen on ultrasonography [2].
Precautions during the examination: do not wear jewelry at the examination site.
X-ray examination
The purpose of the examination: to observe the size of the heart and the morphology of the pulmonary artery.
Significance of the examination: If the right ventricle is enlarged and the pulmonary artery segment protrudes through X-ray examination of the lungs, the lung field is clear, the apical heart shifts upward to the left, and the heart shadow is enlarged [2].
Precautions during the examination: do not wear jewelry at the examination site.
Electrocardiogram
Purpose of examination: to determine the effect of pulmonary artery stenosis on the electrophysiological activity of the heart.
Significance of examination: If the patient has mild stenosis, the electrocardiogram is normal; if the stenosis is moderate or severe, the electrical axis is rightward deviated, the P wave is hyperacute, and the right ventricle is hypertrophied. The degree of right ventricular hypertrophy on ECG is proportional to the severity of stenosis [2].
Precautions during the examination: do not go for ECG in a hurried state, and it is better to rest before the examination.
Right heart catheterization
Purpose: To determine the severity of pulmonary valve stenosis based on the difference in pressure steps between the right ventricular systolic pressure and the pulmonary artery.
Significance: Right heart catheterization can measure the pressure of the pulmonary artery and the right ventricle to calculate the pressure step difference and assess the severity of stenosis, and the systolic pressure step difference between the right ventricle and the pulmonary artery is more than 1.3Kpa [2].
Right ventriculography
Purpose: To determine the severity of pulmonary stenosis.
Significance of examination: right ventriculography can show the valve morphology and the site of stenosis, the thickening of the valve, the pulmonary valve can usually be seen in systole in the form of a dome, and the jet sign can be seen at the valve orifice [2].
Laboratory tests
Brain natriuretic peptide test (bnp test)
Purpose of the test: To determine the diagnostic criteria for heart failure.
Significance of the test: heart failure is considered if the BNP value is greater than 500pg/ml; if the BNP value is less than 100pg/ml, heart failure can be basically excluded.
Differential diagnosis
Tetralogy of Fallot
Similarities: Similar clinical manifestations, such as lip and mouth bruising, dyspnea, fatigue, etc.
Differences: patients with tetralogy of Fallot have reduced dyspnea and lip bruising when squatting down, and the phenomenon of pestle fingers with enlarged ends, while pulmonary stenosis usually does not have this symptom [5].
Ventricular septal defect
Similarities: both have symptoms such as dyspnea after exertion, panic attacks, and easy fatigue and weakness.
Differences: patients with ventricular septal defects experience recurrent respiratory infections, which are symptoms such as coughing, sputum, and fever [5].
Atrial septal defect
Similarity: There is little difference in symptoms between the two, both have symptoms such as dyspnea after exertion, panic attacks, and easy fatigue and weakness.
Differences: Chest X-ray shows enlarged right atrium and right ventricle, protruding pulmonary artery segment, small aortic node, which is typical of a “pear-shaped heart”, and interatrial septal defect can be seen in echocardiography [5].
Treatment
The purpose of treatment: to improve circulation, prolong the survival period, and reduce the incidence of complications.
Treatment principle: no obvious clinical symptoms, normal electrocardiogram, X-ray examination of the heart shadow is normal may not be operated. Symptoms are obvious, electrocardiogram or X-ray shows that the right heart is enlarged, and the systolic pressure difference of the right ventricle and pulmonary artery is more than 8Kpa, all of them should be operated.
Surgical treatment
Percutaneous balloon pulmonary valvuloplasty
The main mechanism of this procedure is to tear the weak part of the valve by balloon dilatation in order to relieve the obstruction, so that the systolic load of the right ventricle is reduced, the contractility of the right ventricle is decreased, and the diastolic function of the right ventricle is significantly improved.
Indications: simple pulmonary stenosis with a trans-pulmonary pressure difference of ≥50 mmHg; adolescent and adult patients with a combination of exertional dyspnea, angina pectoris, syncope, or syncope with aura [5].
Contraindications: subfunnel stenosis, pulmonary stenosis with congenital subvalvular stenosis, pulmonary stenosis with supravalvular stenosis; severe dysplastic pulmonary stenosis; pulmonary stenosis with severe tricuspid regurgitation requiring surgical management.
Complications: intraoperative arrhythmias, tricuspid valve damage and secondary pulmonary valve closure insufficiency.
Endocardial direct vision surgery
Surgical approach: Extracorporeal circulation is established through a median sternal incision, and endocardial visualization is performed under cardiac arrest or beating:
In valvular stenosis, a junctional dissection is performed through a pulmonary artery incision;
For funnel stenosis, the right ventricular outflow tract is incised, and the fibromuscular ring as well as the hypertrophied wall bundles and septal bundles of myocardium are removed anteriorly to unblock the right ventricular outflow tract; if stenosis relief is still unsatisfactory, the right ventricular outflow tract can be widened with an autologous pericardium or a patch of artificial material;
In the case of annular stenosis, the annulus should be incised and a transannular patch from the right ventricular outflow tract to the pulmonary artery should be made to widen the right ventricular outflow tract;
Stenosis of the pulmonary artery trunk and its branches should be widened with pericardial or artificial material patches according to the stenosis site. Septal stenosis of the pulmonary artery can be directly resected septally.
Indications: This procedure is used as an alternative to percutaneous balloon valvuloplasty for patients with pulmonary stenosis who have failed percutaneous balloon valvuloplasty or whose anatomy is unsuitable for percutaneous balloon valvuloplasty; it is the first choice of treatment for subpulmonary stenosis and supra-pulmonary stenosis.
Precautions: This surgical procedure is more traumatic and requires attention to the care of the surgical incision to avoid infection. Meanwhile, active rehabilitation should be carried out.
Medication
Anti-Right Heart Insufficiency Treatment
Common drugs: Digoxin, furosemide, torasemide and other drugs.
Purpose of medication: to relieve the symptoms of heart failure. Suitable for mild to moderate patients [1,6-7].
Contraindications: contraindicated in patients with low blood pressure, and allergy to drugs [8-10].
Prognosis
Cured
Untreated
With the progression of the disease, the patient’s symptoms may gradually aggravate, and may even have serious conditions such as respiratory distress, which seriously affects the patient’s normal life and jeopardizes life and health.
After treatment
The patient’s symptoms can be relieved and the disease can be cured without sequelae, without affecting the patient’s normal life and life expectancy.
Harmfulness
The pulmonary artery is connected to the right ventricle. When there is stenosis of the pulmonary valve the blood discharge from the right ventricle is blocked, leading to an increase in the pressure of the right ventricle, which will ultimately cause the right ventricle to enlarge, leading to right heart or even total heart failure.
Patients with mild stenosis of the pulmonary valve usually have no obvious discomfort, while patients with moderate to severe stenosis may experience difficulty breathing, shortness of breath, and in severe cases, fainting or even sudden death during activities.
Daily
Daily management
Take more vitamins and eat vegetables and fruits in moderation.
Under the guidance of the doctor, appropriate exercise can be carried out, avoiding strenuous exercise.
In order to avoid a strong psychological reaction, you can ease the tension through music. Playing relaxing music can effectively ease the tension and reduce the discomfort.
Get plenty of sleep and maintain a regular routine to keep your body energized.
Follow-up
Children with pulmonary stenosis should be followed up regularly at 1 month, 3-6 months, and annually thereafter, so that any restenosis or pulmonary regurgitation that occurs after surgery can be detected in a timely manner.
Prevention
The mother and fetus can be monitored for maternal diseases and fetal malformations before and during pregnancy.
Before pregnancy, women should eat a reasonable diet, abstain from smoking and alcohol, stay away from toxic and harmful substances, and take folic acid supplements.
Women should increase nutrition appropriately before pregnancy and strengthen physical exercise to enhance the ability to resist diseases.
During pregnancy, obstetrical examination should be conducted on time, so as to make timely diagnosis on whether the fetus is suffering from hereditary diseases and congenital defects.