Intracardiac shunt right to left

Introduction The heart has a mild to moderate increase in pulmonary circulation, and there is a pressure difference between the enlarged right atrium and the functional right ventricle, and the intracardiac shunt is right to left. This symptom belongs to the stenosis of Ebstein syndrome.

Cause

Pulmonary circulation blood flow is reduced, and there is a pressure difference between the enlarged right atrium and the functional right ventricle.

an examination

Related inspection

Electrocardiogram selective cardiovascular angiography Doppler echocardiography dynamic electrocardiogram (Holter monitoring) mammography X-ray examination

The diagnosis of Ebstein syndrome, clinical symptoms and signs may give important tips, but to make an accurate diagnosis depends on the following auxiliary examinations, especially selective angiography.

Electrocardiogram

The P-wave amplitude is increased and/or broadened, and the notch is sometimes visible, with the II, III, aVF, and V1 leads being the clearest. Some people think that the degree of P wave changes is related to the prognosis. People with normal P waves are often asymptomatic; those with significant abnormalities are not only often symptomatic but also easily die rapidly in a short period of time. The PR interval is often prolonged, and complete or incomplete right bundle branch block is seen in almost every patient. Limb leads and right chest leads often have low voltages. Occasionally, right ventricular hypertrophy, but no left ventricular hypertrophy.

It has recently been pointed out that the QRS complex of the V1~4 lead is Qr-type with T-wave inversion, which is a specific electrocardiogram change of this malformation.

About 5% to 25% of patients with this malformation have pre-excitation syndrome (type B). Among those with congenital heart disease and pre-excitation syndrome, 30% were Ebstein malformations. Therefore, clinically, when congenital heart disease with pre-excitation syndrome, the possibility of Ebstein malformation should be suspected. This malformation can occur in a variety of arrhythmias, with paroxysmal supraventricular tachycardia being common, even without pre-excitation syndrome. Other arrhythmias such as atrial premature contraction, atrial flutter or atrial fibrillation are visible.

2. X-ray inspection

In patients with mild deformity, the heart enlargement is not obvious and the pulmonary blood is normal. In patients with moderate or severe deformities, the heart expands to the sides, mainly for the enlargement of the right atrium. Under the fluoroscopy, the heart beat is not obvious, and it is not commensurate with the enlarged heart, similar to the X-ray signs of pericardial effusion or pulmonary stenosis with heart failure. Due to the enlargement of the right atrium and the shifting of the right ventricular outflow tract to the left, the heart shadow can be square or funnel shaped, and a few lesions can be spherical. Pulmonary blood is reduced, and the aortic node is normal or small.

3. Echocardiography

The most typical manifestation is an increase in the amplitude of the anterior tricuspid lobes and a closure delay (at least 0.04 s after the mitral valve is closed). In addition, if the probe is placed in the area where the right ventricle is generally displayed, the giant heart chamber (the right ventricle of the room) can be seen, and the EF slope of the tricuspid valve (the early closing movement of diastole) is also slowed down.

4. Right heart catheterization

In the past, Ebstein syndrome was considered to be very dangerous for cardiac catheterization, and it is prone to severe arrhythmia and even life-threatening. Therefore, if you do not consider cardiac surgery, it is best not to do this check. It is now believed that if the clinical diagnosis is unknown, it should be carried out despite the danger. Under the condition of experienced personnel and rescue equipment, the danger is not great. A group of internationally studied 505 patients with this malformation, 363 patients underwent catheterization and angiography, and 100 patients had arrhythmia, including 13 deaths.

When the right heart catheter is examined, the catheter is often coiled in the enlarged right atrium. Manipulating the catheter often sends the tip of the catheter into the left atrium (via the heart chamber) but it is difficult to access the right ventricle.

The pressure in the right atrium is higher, and the right atrial pressure curve shows a wave and v wave increase. The right ventricle has a high diastolic pressure and the systolic blood pressure is normal or slightly higher. Pulmonary arterial pressure is normal or low. When the catheter is drawn from the pulmonary artery to the right ventricle, or from the right ventricle to the right atrium, and the pressure curve is continuously recorded, there is a systolic pressure difference on both sides of the pulmonary valve, and there is a diastolic pressure difference on both sides of the tricuspid valve.

In most patients, there is a right-to-left shunt at the atrial level, and even a horizontal to left shunt can be found at this level.

It should be specifically mentioned here that if the pressure curve and the intracardiac electrocardiogram can be recorded simultaneously, it is often found that there is a transition zone between the right atrium and the functional right ventricle. The pressure recorded in the area is the same as the right atrium, while the intracardiac electrocardiogram is the same as the right ventricle. This transition zone is the right ventricle of the room. This finding often contributes to the diagnosis of Ebstein syndrome.

Differential diagnosis

The diagnosis of Ebstein syndrome, clinical symptoms and signs may give important tips, but to make an accurate diagnosis depends on the following auxiliary examinations, especially selective angiography.

1. Electrocardiogram;

2. X-ray inspection;

3. Echocardiography;

4. Right heart catheterization.

It should be specifically mentioned here that if the pressure curve and the intracardiac electrocardiogram can be recorded simultaneously, it is often found that there is a transition zone between the right atrium and the functional right ventricle. The pressure recorded in the area is the same as the right atrium, while the intracardiac electrocardiogram is the same as the right ventricle. This transition zone is the right ventricle of the room. This finding often contributes to the diagnosis of Ebstein syndrome.

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