intracardiac myxoma
Introduction
Introduction to myxoma in the heart Cardiac myxoma is the most common primary cardiac tumor in the clinic. It is generally considered benign and has some complex manifestations and malignant tendencies. However, it is also considered to be a malignant tumor with a lower degree of malignancy. Myxoma can occur in all hearts. Endocardial surface, 95% occur in the atria, about 75% in the left atrium, 20% in the right atrium, 2.5% in the left and right ventricles, left atrial mucinous tumor often occurs in the vicinity of the egg garden, clinically often caused by tumor The body blocks the mitral valve, resulting in mitral stenosis or insufficiency. Myxoma can occur at any age, but is most common in middle age and is more common in women. basic knowledge The proportion of illness: 0.002% Susceptible people: no specific population Mode of infection: non-infectious Complications: premature beats atrioventricular block edema
Cause
Cause of myxoma in the heart
Myxoma can occur in the endocardial surface of all hearts, 95% in the atria, about 75% in the left atrium, 20% in the right atrium, and 2.5% in the left and right ventricles. Left atrial mucinous tumors often occur in the egg orchard. Near the nest, clinically often blocked by the tumor mitral valve mouth, resulting in mitral valve stenosis or insufficiency, myxomas can occur at any age, but most common in middle age, more common in women, tumor size is not the same The pedicle is connected to the atrium or ventricular wall. The shape is diversified and the appearance is shiny. It is translucent jelly. Myxoma can occur in the endocardial surface of all the heart.
Prevention
Intracardiac myxoma prevention
There are no special and effective preventive measures for this disease. Early detection, early diagnosis and early treatment are the key to prevention and treatment. Secondly, attention should be paid to the prevention of postoperative complications.
1. Prevention of myxomas debris embolism
(1) The right heart tumor is used to clamp the pulmonary artery before the heart incision, so that the debris does not enter the pulmonary artery.
(2) After the tumor is removed, the heart is thoroughly rinsed.
(3) Before releasing the aortic forceps, the aortic vent is fully drained, and the tiny tumor plug is discharged.
2. Prevention of postoperative low cardiac output syndrome (especially in the left ventricular incision)
(1) Improve heart function before surgery.
(2) Avoid unnecessary excessive, excessive incision damage.
(3) Fully protect the heart muscle.
(4) Maintain electrolyte (potassium, magnesium, calcium), blood volume, and blood quality in the normal range.
Complication
Myxoma complications in the heart Complications premature beat atrioventricular block edema
The most common complications after general cardiac myxoma are:
1, heart rhythm disorder and atrioventricular bundle block: generally speaking, transient, through the intravenous infusion of lidocaine for ventricular premature beats, transient complete atrioventricular block with intravenous infusion of isoproterenol Maintain heart rate, if necessary, place temporary pacing in the venous heart, and remove the pacing lead after the sinus rhythm is restored.
2, systemic circulation embolism: often caused by tumor fragmentation, the main blood vessel embolism can cause brain tissue hypoxia, edema and necrosis, the patient is unconscious or even dead, the body is embolized by other important organs, in the expansion of vascular drugs and In the case of ineffective anticoagulant therapy, an open vascular thrombectomy should be performed.
3, the disease is also in danger of sudden death.
Symptom
Symptoms of myxoma in the heart Common symptoms Myocardial globulin abnormal pericardial effusion dyspnea shortness of jugular vein engorgement hepatomegaly weight loss paroxysmal vertigo edema
The clinical manifestations of this disease depend on the location, size, nature, and presence or length of the tumor. The tumor pedicle is prone to cause atrioventricular valve stenosis or regurgitation, and hemodynamic changes occur. Symptoms, short tumors of the tumor, can be asymptomatic for a long time.
(1) Obstructive symptoms: early palpitations, shortness of breath, decreased exercise tolerance, left atrial myxoma such as obstructive pulmonary vein or mitral valve can produce pulmonary sputum symptoms similar to mitral valve disease; paroxysmal nocturnal dyspnea, hemoptysis Silk sputum, severe cases may have jugular vein engorgement, hepatomegaly and lower extremity edema, right atrial myxoma such as obstruction of the vena cava, tricuspid valve can appear similar to pericardial effusion; jugular vein engorgement, hepatomegaly And edema, the obstructive symptoms of this disease have the characteristics of seizures with changes in body position. If there is paroxysmal vertigo associated with body position and dyspnea, the tumor suddenly blocks the atrioventricular valve and causes a significant decrease in stroke volume, which may cause sudden fainting or heart. Sudden stop.
(B) embolization: mucinous tumor fragments or tumor surface thrombosis can occur in the body, embolism of the pulmonary circulation, left atrial myxoma about 40% embolization, right atrial myxoma embolism is rare.
(C) systemic symptoms: mainly fever, increased erythrocyte sedimentation rate, anemia, weight loss and abnormal increase of serum 2, globulin, which may be related to hemorrhagic necrosis and inflammatory cell infiltration in the tumor.
Examine
Examination of myxoma in the heart
Electrocardiogram
Not a diagnosis basis, although there may be various changes such as right bundle branch block, I degree atrioventricular block, pre-systolic contraction, atrial fibrillation, atrial enlargement, ST or T wave changes, ventricular hypertension, ventricular hypertrophy, etc. .
2. X-ray chest film
It can show some changes in pulmonary congestion and heart shape. If the pulmonary congestion and heart shadow change lightly and the symptoms are heavier, the signs are more obvious, suggesting the possibility of cardiac myxoma, but it can only be used as an important reference and cannot be diagnosed.
3. Cardiac catheterization
Can show cardiopulmonary function changes, but does not help the diagnosis of cardiac myxoma, and for invasive examination, there is the risk of tumor rupture, debris detachment and embolism, especially left atrial puncture should be listed as taboo.
4. Selective or digital subtraction
Cardiac angiography is also an invasive examination. Although it may indicate a filling defect, it indicates a space-occupying lesion. However, for a more active intracardiac myxoma (such as the left atrium), the general velocity imaging series is difficult. There is a very clear image, and the dynamic image of the non-invasive echocardiogram is not clear.
5. Radionuclide blood pool scanning
Imaging is a small invasive examination, which can clearly show the tumor negative in the heart chamber, and is not as non-invasive and simple as echocardiography.
6. Computer X-ray scanning cross-section tomography
(CT) , magnetic resonance imaging (MRI) are non-invasive, can also clearly show the intracardiac space-occupying lesions, but expensive, expensive, not suitable for routine examination of cardiac myxoma.
7. Laboratory inspection
Cardiac myxoma, especially in cases with severe systemic reactions, often have anemia (hemoglobin can be as low as 40 ~ 50g / L), ESR increased (can be > 120mm / h), immunoglobulin IgM, IgG, IgA and many other changes, However, there is no specificity. These changes can only be used as a reference for understanding the general condition and cannot be used as a basis for diagnosis.
8. Ultrasound of cardiac myxoma
Cardiographic diagnosis of M-mode ultrasound can make a qualitative diagnosis, but two-dimensional echocardiography is the preferred method. For quantitative diagnosis, it can reflect the following characteristics: tumor morphology and contour; tumor size; differential localization and diffuse tumor; tumor margin Whether the echo is clear, whether there is echo of the capsule; identify the intracardiac, myocardium, heart wall and extracardiac tumor; the extent of invasion is single-cardiac or multi-cardiac; showing the attachment site, length, or other forms of pedicle The starting point; the degree of morphological variation during tumor movement; the number of tumors; the degree of echo and distribution of the tumor; secondary changes including enlarged heart deformation, abnormal valve function, pericardial effusion.
(1) The diagnosis of left atrial myxoma is based on:
1 An abnormal point-like echo gathers in the left atrium, with a clear outline and a regular edge. It is roughly elliptical and has a long elliptical group echo. The internal echo intensity is relatively uniform, and the base is on the interatrial septum. If the pedicle is large, the location and size of the pedicle can be displayed;
2 The tumor echo of the tumor moves with the cardiac cycle in the left atrium, between the left ventricle, and all the tumors in the systolic phase can return to the left atrium. The diastolic phase reaches the mitral valve or enters the left ventricle through the mitral valve. The position in the left atrium of the left atrium varies with the attachment location of the pedicle and the size and shape of the tumor;
3 On the short axis of the left ventricular mitral valve, it can be seen that the systolic tumor echoes behind the mitral valve, can be separated from the mitral valve, and retracts to the left atrium. The diastolic tumor moves with the blood flow and passes through the mitral valve. The left ventricle, the rounded mitral valve can be filled with tumor echoes.
(2) Right atrial myxoma: similar to left atrial myxoma, the abnormal echogenic group of myxoma is in the right heart chamber, the systolic phase is in the right atrium, and the diastolic phase moves to the right ventricle with the tricuspid valve to the right ventricle, or Through the tricuspid valve into the right ventricular cavity, and even into the right ventricular outflow tract (can be found under the rib to obtain a clear tumor echo pattern, the inferior vena cava long-axis view can be observed at the entrance of the inferior vena cava at the entrance of the right atrial mucinous tumor) .
(3) ventricular myxoma: systolic abnormal echo group into the left ventricular outflow tract or right ventricular outflow tract, diastolic in the left ventricular or in the right ventricle, visible abnormal echo group in the ventricular cavity with the direction of blood flow regular swing.
(4) multiple myxoma of the heart: the left atrium is the most common, the right atrium is the second, the left ventricle is less, and the right ventricle is the least. The two-dimensional ultrasound has a certain diagnostic value, but if it is a multiple myxoma in the same heart chamber, the ultrasound pair Affirmation of the number and size of tumors may be inaccurate, and it is necessary to exchange multiple positions of the body to prevent missing tumors with small tumors and small activity.
Diagnosis
Diagnosis and differentiation of myxoma in the heart
1, left atrial myxoma should pay attention to, and cusp stenosis identification, cusp stenosis often have a loud opening sound, few first, heart sounds, murmur does not change with body position, no flutter, suspicious If the echocardiography can be performed, it can be identified that the spherical thrombus in the left atrium is also easily confused with the left atrial myxoma. In the echocardiogram, most of the left atrial thrombus appears in the posterior wall of the left atrium, and its abnormal reflection beam is lacking. With the rapid movement of the heartbeat cycle, left atrial thrombus is often associated with stenosis of the cusp, and thus the reflex pattern of abnormal mitral activity.
2, right atrial myxoma should pay attention to constrictive pericarditis, cusp stenosis, pulmonary stenosis differentiation, sternal left margin, -, intercostal systolic and diastolic friction like back and forth murmur, symptoms, murmur and body position change Relevant and so on have differential diagnostic value.
