Pregnancy with patent ductus arteriosus

Introduction to pregnancy with patent ductus arteriosus Patent ductus arteriosus (PDA) is a common congenital cardiovascular malformation with a relative composition ratio of 5% to 20% in congenital heart disease. The arterial catheter is a blood vessel connecting the pulmonary artery and the descending aorta. The fetal lung has no respiration, so most of the blood does not enter the lungs. The pulmonary artery is transferred into the aorta through the arterial catheter. Its main function is to contain oxygen and nutrients. Right ventricular blood is transported to the aorta to meet the needs of fetal metabolism. After birth, with the development of pulmonary respiratory function and pulmonary vasodilation, the arterial catheter loses its role and gradually occludes. If the catheter is still open after birth, it is a patent ductus arteriosus. basic knowledge The proportion of illness: this disease is rare, the incidence rate is about 0.0001%-0.0005% Susceptible population: newborn Mode of infection: non-infectious Complications: pulmonary stenosis congenital aortic coarctation ventricular septal defect

Pregnancy associated with patent ductus arteriosus

(1) Causes of the disease

It is currently believed that the disease is caused by multi-factor interactions, including genetic factors and maternal infection, maternal medication, environmental factors, and metabolic factors.

Genetic factor

One parent has a congenital heart disease, and the probability of her child suffering from congenital heart disease is much higher than that of the general population. Some meningitis patients have significant differences in the incidence of congenital heart disease. For example, mitral valve prolapse syndrome is mainly found in women, and various hereditary diseases often combined with congenital heart disease. The presence of 50% of patients with Nonan syndrome has a cardiac malformation, of which 60% is pulmonary stenosis, 20% is atrial septal defect and hypertrophic cardiomyopathy, and congenital heart disease can be caused by single gene mutation, polygenic inheritance and chromosomal aberration. Genetics believes that congenital heart disease is formed by genetic factors triggered by environmental factors (teratogenic factors).

2. Maternal disease

Mainly mothers infected with pregnancy or other diseases, mothers infected with rubella virus at the beginning of pregnancy, their children are prone to pulmonary stenosis and patent ductus arteriosus; pregnant women with Coxsackie B virus infection are prone to patent ductus arteriosus or ventricle In infants with septal defect, the infection that causes congenital heart disease is mainly a virus, whether it causes distortion and the type of virus, and the time of infection. Women with type 1 diabetes, 3% to 5% of the babies born have various types of congenital heart disease, thyroid gland Hyperfunction, pregnant women with hyperphenylalaninemia are easy to give birth to infants with congenital heart disease.

3. Drugs

Pregnant women taking hormonal drugs can increase the risk of congenital heart disease by 2 times; taking phenytoin in early pregnancy can cause cardiovascular malformations; long-term use of tolbutamide (methanebutazone) and continued use during pregnancy can cause embryos to have atrial septum Defects, ventricular septal defects and other malformations, taking drugs on the 40th to 50th day of pregnancy is likely to be the main cause of congenital heart disease.

Premature birth

Premature infants, especially those weighing less than 2500 g, have more patent ductus arteriosus and ventricular septal defect, which is associated with insufficient time for development.

5. Plateau environment

In the plateau, the oxygen partial pressure is low, and there are more infants with patent ductus arteriosus and atrial septal defect.

(two) pathogenesis

1. Pathological anatomy in the normal left aortic arch, the arterial catheter is located between the aortic isthmus and the left pulmonary artery root, the common pulmonary artery bifurcation, in a few right aortic arch, the catheter is located between the root of the innominate artery and the right pulmonary artery. There is no respiratory function in the fetal lung, so most of the blood does not enter the lungs. The pulmonary artery is transferred into the aorta through the arterial catheter. The open arterial catheter is the physiological blood flow channel necessary for survival. After birth, hemodynamics The change quickly closes, the middle layer of the catheter becomes a fibrous structure, and the lumen is closed to form a fibrous cord, which is called an arterial catheter ligament. 95% of the babies are occluded 1 year after birth (80% of the babies are 3rd after birth) Month occlusion), and thus still not occluded, resulting in left-to-right shunt of pulmonary artery level, and hemodynamic disorder.

2. Pathophysiology

(1) Left-to-right shunt: In the uncomplicated patent ductus arteriosus, since the aortic pressure is always higher than the pulmonary artery in the systolic or diastolic phase, a continuous left-to-right shunt of the pulmonary artery level is produced, which is clinically continuous. Sexual noise, pulmonary congestion, and the amount of sub-flow depends on the pressure gradient between the aorta and the pulmonary artery, the thickness of the arterial catheter, and the level of pulmonary vascular resistance.

(2) left ventricular hypertrophy: due to the left-to-right shunt of the patent ductus arteriosus, the blood flow in the left atrium is increased, so the blood return of the left atrium is increased, the volume load of the left ventricle is increased, and the left-to-right shunt is reduced. The left ventricle compensates for the work, which leads to enlargement of the left ventricle, hypertrophy, and even failure.

(3) pulmonary hypertension and right ventricular hypertrophy: when the patent ductus arteriosus is thicker, the blood flow to the pulmonary artery may cause an increase in pulmonary artery pressure, which eventually leads to right ventricular hypertrophy, dilatation, and even failure.

(4) Bidirectional or right-to-left shunt: As the disease progresses, the pulmonary artery pressure increases. When the aortic pressure is approached or exceeded, a bidirectional shunt or a right-to-left shunt is generated, which is converted into Eisenmenger. Syndrome, clinically different hair cyanosis.

(5) The diastolic blood pressure of the peripheral artery decreases, and the pulse pressure is widened: this is because during the diastolic phase, the blood of the aorta is still divided into the pulmonary artery, and the blood flow of the systemic circulation is reduced.

3. Interaction with pregnancy Because of the simple clinical diagnosis, isolated arterial catheterization in childhood can often be cured, so it has little relationship with pregnancy, the catheter is fine and the shunt is less, and the pulmonary artery pressure is normal, except for the infectious heart during childbirth. In addition to endometritis, the maternal period is more smooth; if there is a large patent ductus arteriosus, a large amount of aortic blood to the pulmonary artery shunt, such as increased pulmonary vascular resistance, can cause significant pulmonary hypertension, so that blood shunt reversal, appear Bun, further reducing the uterine artery oxygen saturation, can endanger the fetus, pregnant women first left heart failure, followed by right heart failure, heart failure is the main cause of such maternal death.

Pregnancy with patent ductus arteriosus prevention

1. Maintain an optimistic and happy mood. Long-term mental stress, anxiety, irritability, pessimism and other emotions will make the balance of the cerebral cortex excitatory and inhibition process imbalance, so you need to maintain a happy mood.

2, life restraint pay attention to rest, work and rest, life orderly, maintain an optimistic, positive, upward attitude towards life has a great help to prevent disease. Make tea and rice regular, live and live regularly, not overworked, cheerful, and develop good habits

Pregnancy with patent ductus arteriosus Complications, pulmonary aortic stenosis, congenital aortic coarctation, ventricular septal defect

The disease can be combined with other malformations such as pulmonary stenosis, aortic coarctation, atrial septal defect, ventricular septal defect, large vessel dislocation and so on.

Pregnancy with patent ductus arteriosus symptoms Common symptoms Chest tightness Heart failure, asthma, hemoptysis, weakness, purpura (toe), nausea after exertion

Symptom

The catheter subdivided flow can be asymptomatic, and the large flow of the catheter can cause symptoms, such as fatigue, nausea after exhaustion, asthma, chest tightness, cough, hemoptysis, in the 32-34 weeks of gestation, because it is the period of maximum heart load, Heart failure can occur in pregnant women.

2. Signs

The typical sign is that there is a loud continuous machine sound murmur in the second intercostal space on the left sternal border. For example, patients with thick catheters and large flow fractions can see that the apex beats to the left and the lower part, and the range is diffused. The first edge of the sternum is the first. Between the second intercostal space and continuous tremor, a small number of patients with pulmonary hypertension caused by right-to-left shunt may only hear diastolic snoring and cyanosis in the pulmonary valve area, and the lower body is obvious.

Pregnancy with patent ductus arteriosus

X-ray inspection

In patients with small flow rate, no abnormal findings can be found. In patients with large partial flow, pulmonary congestion, pulmonary artery thickening and pulsation enhancement, pulmonary artery dry arch bulge, aortic arch shadow, left ventricular enlargement, and nearly half of patients can be seen. It can be seen that the aorta has a local funnel-like bulge at the attachment of the arterial catheter, which is called a funnel sign. It is manifested in the orthotopic slice in which the aortic node is under the shadow and does not adduct and continues to swell, the hilar vascular shadow is thickened, and the lung is congested. Dilated to the left, then obliquely inward to the descending aorta shadow, in the left anterior oblique slice, the aorta suddenly contracted inward at the beginning of the descending aorta, occasionally seen in the left atrium in the aortic arch There is a calcified shadow of the patent ductus arteriosus near the lower end. 2. There are four types of changes in ECG: normal, left ventricular hypertrophy, left and right ventricle with hypertrophy and right ventricular hypertrophy, both of which are associated with a corresponding degree of pulmonary hypertension.

3. Echocardiography

It can be seen that the left ventricular internal diameter increases, the amplitude and velocity of the mitral valve increase, and the two-dimensional echocardiography may show the patent ductus arteriosus. Color Doppler flow imaging can detect the catheter from the descending aorta through the patent ductus arteriosus. Blood flow into the pulmonary artery.

4. Cardiac catheterization and selective indicator dilution curve determination

The main finding of right heart catheterization is that the blood oxygen content of the pulmonary arteries is higher than that of the right ventricle, the blood flow of the lungs is increased, the pulmonary artery and right ventricular pressure may be normal or slightly increased, and the cardiac catheter may enter the descending artery through the patent ductus arteriosus. Aorta, pulmonary hypertension can be increased in two-way or right-to-left shunt, when the arterial blood oxygen content, especially in the lower extremity arterial blood oxygen content, in patients with less closed arterial catheters from the left to the right of the flow, hydrogen Dilution curve determination can be found in its shunt.

5. Selective cardiovascular angiography

Selective aortic angiography showed aortic arch development while the pulmonary artery was also developed, and sometimes the aortic local funnel-like bulging of the patent ductus and arterial catheter attachment was observed. Sometimes the proximal ascending aorta and aortic arch were dilated. The distal aorta has a thinner diameter.

Diagnosis and differential diagnosis of pregnancy complicated with patent ductus arteriosus

diagnosis

According to typical murmurs, X-ray examination, electrocardiogram and echocardiography, the disease can be diagnosed fairly accurately. Individual cases can be further diagnosed by right heart catheterization before pregnancy.

Differential diagnosis

The patent ductus arteriosus must be differentiated from other diseases that are sufficient to cause cardiac continuity murmur.

Congenital aortic-pulmonary septal defect

For the development of fetal aortic septal dysplasia, the aortic-pulmonary artery is left with a defect, its clinical manifestations are similar to large patent ductus arteriosus, the differential diagnosis is extremely difficult, the continuous machine sounds louder, the position is lower (lower intercostal space) can be used as a reference for differential diagnosis, but it is not very reliable. The more reliable differential diagnosis method is the ascending part of the cardiac catheter from the pulmonary artery into the aorta during right heart catheterization. The retrograde ascending aorta is seen as the ascending main. Arterial and common pulmonary arteries are simultaneously developed. Two-dimensional echocardiography shows widening of the common pulmonary artery and aorta. There is a defect communication between them, which is also helpful for diagnosis. If there is a right-to-left shunt in the pulmonary hypertension, there is a hair loss. Upper and lower extremity arteries have equal blood oxygen levels, which is not the same as patent ductus arteriosus.

2. Aortic sinus aneurysm breaks into the right heart

An aortic sinus aneurysm caused by congenital malformation, syphilis or infective endocarditis can erode and penetrate into the pulmonary artery, right atrium or right ventricle, causing left to right shunt, continuity The sound of the machine is similar to the patent ductus arteriosus, but the position is often 1 to 2 intercostal. The disease has a history of sudden onset, such as sudden palpitations, chest pain, chest tightness or chest discomfort, feeling tremor in the left chest, etc. Then there is the performance of right heart failure, which can help diagnose.

3. supraventricular supraventricular ventricular septal defect with aortic regurgitation

A supraventricular ventricular septal defect, such as just under the aortic valve, may pull a leaf of the aortic valve down, or may be caused by blood flow impinging into the left ventricle due to lack of tissue support in the lower part of the valve. Aortic regurgitation, systolic murmur caused by ventricular septal defect itself, and diastolic murmur caused by aortic regurgitation, can produce murmurs in the 3rd and 4th intercostals of the left sternal border Similar to the patent ductus arteriosus or aortic-pulmonary septal defect murmur, but the disease has a lack of typical continuity, ECG and X-ray examination show significant left ventricular hypertrophy, echocardiography and right heart catheterization can help Identification.

4. Other

Anything that is sufficient to cause a continuous machine-like murmur in the left front chest, such as coronary arteriovenous fistula, left upper lobe pulmonary arteriovenous fistula, left anterior chest wall arteriovenous fistula, left neck neck jugular vein camping sound, etc. Identification.

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