Rhabdomyomas of the heart
Introduction
Introduction to cardiac rhabdomyomas Rhabdomyomaofheart is the second most common benign cardiac tumor after myxomas and the most common primary cardiac tumor in children. It is more common in newborns and infants. Some people call it heart hamartoma, Purkinje cell tumor and histiocytoid cardiomyopathy. It accounts for about 8% of the total heart tumor. 90% of children under the age of 15 and 78% are under 1 year of age. As the tumor blocks the heart chamber, the baby may die soon after birth. basic knowledge The proportion of illness: 0.0006% Susceptible people: children Mode of infection: non-infectious Complications: congestive heart failure, arterial embolism
Cause
Causes of cardiac rhabdomyosarcoma
(1) Causes of the disease
The disease is considered to be a hamartoma rather than a true tumor, possibly derived from fetal cardiac myoblasts, and is the most common primary cardiac tumor in infants and children.
(two) pathogenesis
1. Pathogenesis At present, the pathogenesis of rhabdomyomas is poorly understood. In newborns and infants, rhabdomyomas account for 60% of cardiac tumors. Some cases have been diagnosed in the uterus. Because of the formation of multiple germ layers, it is considered to be A hamartoma, rather than a true new organism, may be derived from the myoblasts of the embryonic heart.
2. Pathological rhabdomyomas are scattered nodular gray or yellow-white masses, about 5mm to 2.5cm in size, without a true tumor capsule, but are benign lesions, 90% of cases are multiple, and a few are isolated. Histologically, a tumor cell like a "spider cell" is composed of a cytoplasm filled with glycogen and a cell filament that extends to the periphery of the cell.
3. Pathophysiology Rhabdomyosarcoma usually penetrates into the myocardial tissue, protruding in the heart chamber, causing obstruction of the heart chamber or obstruction of the corresponding part of the valve, thereby affecting the function of the left and right ventricles, which may occur due to the involvement of the primary mass in the conduction tissue. A change in heart rhythm, or occurs in the heart chamber causing heart valve obstruction.
Prevention
Cardiac rhabdomyooma prevention
The mechanism of cardiac rhabdomyomas is not well understood. There is no specific preventive method at present, but the understanding of the disease, early diagnosis and early treatment can alleviate the symptoms of obstruction, protect the function of ventricle and valve, and prevent damage to the injury conduction system. Partially improve the prognosis of this disease.
Complication
Cardiac rhabdomyosarcoma complications Complications, congestive heart failure, arterial embolism
Complications such as congestive heart failure, arterial embolism, and bacterial endocarditis can occur.
Symptom
Symptoms of rhabdomyosarcoma of the heart Common symptoms Heart murmur Arrhythmia Heart enlargement Deciduous atrioventricular block Obstruction of pericardial effusion
The clinical manifestations of patients with rhabdomyosarcoma of the heart depend on the size, number and location of the tumor. The initial common signs are heart murmurs, which are prone to blood flow obstruction and arrhythmia. Small tumors are generally asymptomatic, and larger tumors can block the heart chamber or The valve causes significant hemodynamic damage. The obstruction of the tricuspid valve can produce a right-to-left shunt of the foramen ovale, which can cause cyanosis; involving the conduction system can produce severe arrhythmias, including complete atrioventricular block and drugs. Uncontrollable ventricular tachycardia.
Specific manifestations of arrhythmia (ventricular or ventricular arrhythmia) and atrioventricular block; heart enlargement, valvular insufficiency (may resemble mitral stenosis, mitral atresia), aortic stenosis, pulmonary valve or Aortic subvalvular stenosis, pericardial effusion, and even sudden death, non-specific manifestations including cardiac enlargement, left ventricular or right ventricular failure and dual-chamber failure, S3 and S4 gallop, systolic or diastolic murmurs, sometimes combined with bacteria Endocarditis, sudden death can occur due to arterial embolism.
Examine
Examination of cardiac rhabdomyomas
Main cardiac echocardiography and cardiac catheterization.
Cardiac echocardiography: Rhabdomyosarcoma is essentially a solid tumor in the myocardium that invades many areas of the myocardium, ranging in diameter from a few millimeters to a few centimeters. Although different in size, it exhibits the identity of the echogenic mass, large rhabdomyomas can cause Obstruction of the inflow or outflow tract of the left and right heart chambers, but no reports of pericardial effusion.
Diagnosis
Diagnosis and diagnosis of cardiac rhabdomyosarcoma
Diagnostic criteria
In the fetal period, if edema or arrhythmia occurs, the diagnosis can be established by two-dimensional echocardiography. If neonatal or infancy occurs, such as severe congestive heart failure or ventricular tachycardia, the disease should be highly suspected and passed ultrasound. Non-invasive imaging techniques such as magnetic resonance or computed tomography are performed. For patients with obstruction or arrhythmia, cardiac catheterization can obtain hemodynamic or electrophysiological data.
Differential diagnosis
Identification of diseases such as cardiac myxoma, myocardial fibroma, and cardiac hemangioma.
1. Cardiac myxoma is the most common type of primary benign tumor of the heart. 80% occurs in the left atrium, and the right atrium and left ventricle are also seen. The incidence of women is slightly more, and the tumor is mostly single, polypoid, spherical or divided. Leaves, soft and brittle, smooth surface, ranging in size from cherry to peach, with different lengths of tumor pedicles, pedicle elders have mobility, can block blood flow caused by symptoms, surface parts of different sizes are easy Shedding caused by shedding, two-dimensional B-ultrasound and magnetic resonance imaging, in addition to the judgment of the morphological characteristics of the tumor, the histological characteristics of myxoma can often make a preliminary judgment.
2. Myocardial fibroma often occurs in the ventricular septum or ventricular wall. The tumor is hard and non-coated. The diameter is usually 3 to 7 cm. Most of the fibroids invade the conduction tissue. The patient suddenly died of arrhythmia. There are nodular sclerosis (mental hypoplasia, convulsions, language defects), which can be identified.
3. Cardiac hemangioma is a rare cardiac tumor characterized by symptoms of cardiac structural compression or outflow tract obstruction. CT enhanced scan or MRI can determine the diagnosis of this highly vascularized tumor.
