Neonatal myocarditis

Introduction to neonatal myocarditis Neonatal myocarditis is a disease in which focal or diffuse myocardial interstitial inflammatory exudation and myocardial fibrosis, lysis and necrosis are caused by various factors in the neonatal period, leading to varying degrees of myocardial dysfunction and systemic symptoms. Can be sporadic or popular, clinical manifestations are not typical, difficult to find early and easy to delay treatment, high mortality, should be paid attention to. basic knowledge The proportion of illness: 0.08%-0.1% Susceptible people: children Mode of infection: non-infectious Complications: neonatal respiratory distress syndrome arrhythmia heart failure pulmonary edema coma

Causes of neonatal myocarditis

Viral infection (65%):

The disease is mainly caused by infection, and the virus infection is more, the most important of which is Coxsackie B virus, which accounts for more than half of the pathogens. It has been isolated to B3, B4, B5, ECHO, cytomegalovirus, rubella, Varicella and adenovirus can also cause the disease, the prevalence of neonatal indoors, often caused by Coxsackie, ECHO virus, and cytomegalovirus, rubella, varicella virus are more common in the mother's pregnancy caused by intrauterine infection, often in the newborn It can be ill in early childhood.

Bacterial infection (35%):

Bacteria, spirochetes, rickettsia, fungi, protozoa, etc. can also be the cause of the disease, viral infections that cause myocarditis can occur in the uterus, during or after birth, when pregnant women with intrauterine infection, the virus can be transmitted through the placenta Fetus, this disease can occur in the baby room, maternal and child in the same room and obstetrics, the disease is serious, the mortality rate is high.

Pathogenesis

The pathological changes of neonatal myocarditis can vary in severity, heart enlargement, pale appearance, myocarditis can be seen under electron microscope, pericarditis, normal heart valve, myocardial lymphocytes, large mononuclear cells, eosinophilic and neutrophil infiltration, more Densely spotted, there are often degenerative changes and necrosis of myocardial fibers in the later stage. In addition to myocardial damage, brain and liver cells are often involved.

Neonatal myocarditis prevention

The prevention of outbreak of neonatal viral myocarditis is very important for prenatal and postnatal care and reducing neonatal mortality. Perinatal health care should be done to protect pregnant women from infection. The management of infant rooms and maternal and child wards should be strengthened. Strictly observe the disinfection and isolation system. When the epidemic occurs, the child should be quarantined for 2 weeks, contact with the quarantine, and the injection of human serum immunoglobulin for susceptible newborns, 0.2ml/kg each time. Currently, the prevention of Coxsackie virus infection. The development of genetic vaccines is underway, and active prevention of birth, suffocation, cold and high fever should be actively prevented.

Neonatal myocarditis complications Complications neonatal respiratory distress syndrome arrhythmia heart failure pulmonary edema coma

Can be complicated by respiratory distress, arrhythmia, heart failure, pulmonary edema, convulsions, coma and so on.

Neonatal myocardial symptoms common symptoms arrhythmia tachycardia drowsiness skin pale breath shortness systolic murmur heart enlargement sound heart sound low blunt

Intrauterine infection occurs within 3 days of birth; the infection at birth is mostly due to inhalation of viral secretions in the vagina, which occurs within 1 week of birth; the symptoms of infection after birth are later, mostly due to neonatal contact with mother, infant room staff Infected persons and infected infants have other infections. The clinical manifestations of neonatal viral myocarditis are atypical and varied.

1. General performance: Symptoms are non-specific, such as fever, cough, poor eating, lethargy, vomiting, diarrhea, rash, pale skin or jaundice, and severe respiratory distress and cyanosis.

2. Cardiac auscultation changes: tachycardia or galloping, which is not proportional to body temperature, has a low heart sound, and some cases have systolic murmur in the precordial area.

3. A variety of arrhythmia: pre-contraction, paroxysmal supraventricular tachycardia, ventricular tachycardia, various conduction block such as sinus, atrioventricular and indoor conduction block.

4. Congestive heart failure: manifested difficulty in feeding, shortness of breath, fast heart rate, weak pulse, low heart sound, blunt heart, enlarged heart, both sides of inhalation can smell fine wet voice, liver, edema, oliguria or no Poor urine and muscle tension in the limbs.

5. Others: Some children may be associated with neurological damage, convulsions, coma, etc., cerebrospinal fluid has a change in aseptic meningitis.

Examination of neonatal myocarditis

1. Serum myocardial enzyme examination: GOT, LDH, CPK, etc. are observed to increase, especially with the increase of LDH isoenzyme LDH1 and CPK isoenzyme CPK-MB.

2. Virological examination: Antibody examination is easier to perform, and early detection of viral IgM is helpful for diagnosis.

3. Myocardial biopsy: confirmed by myocardial biopsy virus isolation.

4. X-ray examination: the heart can be enlarged, the heart beat is weakened under fluoroscopy, and the lung texture is increased. If there is heart failure, the X-ray may have pulmonary edema.

5. Electrocardiogram: ECG mainly shows I, II, aVF, V5, V6 and other leads ST segment decline, T wave low level, inverted, two-way, severe ST segment elevation is a one-way curve with deep Q wave, similar The pattern of adult myocardial infarction indicates severe myocardial damage and may have various manifestations of arrhythmia: pre-systolic, supraventricular or ventricular tachycardia, atrial flutter, tremor, atrioventricular, sinus, bundle Conduction block and so on.

6. Echocardiography: visible heart enlargement, pulsation weakening and cardiac dysfunction.

Diagnosis and diagnosis of neonatal myocarditis

diagnosis

1. Diagnosis of neonatal myocarditis: Due to the atypical clinical manifestations of neonatal myocarditis, the diagnosis has certain difficulties. In September 1999, the National Symposium on Pediatric Myocarditis and Heart Disease was held in Kunming. The participants discussed it completely and revised it in 1994. The Diagnostic Criteria for Viral Myocarditis in Children was prepared at the Weihai Conference in Shandong Province. The revised diagnostic criteria are now published for reference by clinicians. The diagnostic criteria cannot be used mechanically. Some patients with mild or insidious passages are easily missed. Only a thorough analysis of clinical data can make a correct diagnosis.

Taking into account the characteristics of the newborn, pay attention to the diagnosis of epidemiological history, such as the outbreak of viral infection in the infant room or the mother's viral infection in the perinatal period, combined with clinical manifestations and ECG changes, myocardial enzymes are positive, The abnormal performance of X-ray examination can consider the clinical diagnosis of neonatal myocarditis.

(1) Clinical diagnosis basis:

1 cardiac insufficiency, cardiogenic shock or heart and brain syndrome.

2 heart enlargement (X-ray, echocardiography has one of the manifestations).

3 ECG changes: ST-T changes in two or more main leads (I, II, aVF, V5) with R waves mainly lasted for more than 4 days with dynamic changes, sinus conduction block, atrioventricular conduction Block, complete right or left bundle branch block, syndrome, polymorphism, multiple sources, paired or parallel premature contraction, atopic tachycardia caused by non-compartmental node and atrioventricular reentry, low Voltage (except newborn) and abnormal Q wave.

4CK-MB is elevated or positive for cardiac troponin (cTnI or cTnT).

(2) Pathogen diagnosis basis:

1 diagnosis indicators: self-contained endocardial, myocardial, pericardial (biopsy, pathology) or pericardial puncture examination, found that one of the following can be diagnosed with myocarditis caused by the virus.

A. Isolation of the virus.

B. Virus nucleic acid probes are detected by viral nucleic acid probes.

C. Specific virus antibody positive.

2 Reference basis: One of the following may be combined with clinical manifestations to consider the myocarditis virus.

A. The virus is isolated from the stool of the child, the throat swab or the blood, and the titer of the serum isotype antibody in the recovery period is increased or decreased by more than 4 times compared with the first serum.

B. The blood in the early stage of the disease is positive for specific IgM antibodies.

C. Viral nucleic acid is detected from the blood of the child using a viral nucleic acid probe.

(3) Basis for diagnosis:

1 With clinical diagnosis basis 2, clinical diagnosis of myocarditis, evidence of viral infection at the same time or 1 to 3 weeks before the onset of the disease supports the diagnosis.

2 At the same time, it has one of the evidences for the diagnosis of pathogens. It can be diagnosed as viral myocarditis and has one of the pathogens. It can be diagnosed as viral myocarditis.

3 Where there is no basis for diagnosis, the necessary treatment or follow-up should be given, and the myocarditis should be diagnosed or excluded according to the change of the condition.

4 should exclude rheumatic myocarditis, toxic myocarditis, congenital heart disease, connective tissue disease and myocardial damage of metabolic diseases, hyperthyroidism, primary cardiomyopathy, primary endocardial fibroelastosis, congenital Sexual atrioventricular block, cardiac autonomic dysfunction, beta-receptor hyperfunction and drug-induced electrocardiographic changes.

(4) Staging:

1 acute phase: new onset, symptoms and positive test findings are obviously variable, the general course of disease is less than half a year.

2 prolonged period: clinical symptoms recurred, objective examination indicators were delayed, and the course of disease was more than half a year.

3 chronic phase: progressive heart enlargement, repeated heart failure or arrhythmia, the condition is light and heavy, the course of disease is more than 1 year.

2. Diagnosis of heart failure with neonatal myocarditis complicated with heart failure, according to the 1985 National Heart Failure Committee Symposium "Diagnostic Standards for Heart Failure", but it should be noted that due to neonatal anatomy and physiology characteristics, heart failure performance can have the following Features:

(1) often left, right heart and heart failure.

(2) can be combined with peripheral circulatory failure.

(3) Heart rate and breathing may not increase in severe cases.

(4) The liver is enlarged and the front line is more obvious.

Differential diagnosis

Because the clinical manifestations of neonatal myocarditis are not typical, attention should be paid to the identification of neonatal pneumonia, endocardial fibroelastosis and so on.

1. neonatal pneumonia (neonatal pneumonia: the difference between this disease and neonatal myocarditis is that the respiratory performance is mainly caused by shortness of breath, after the oxygen can be significantly improved; the heart sound is not low, the arrhythmia and heart failure are rare, even Heart failure is also easier to control, X-ray examination of the heart is more normal, there is excessive lung congestion, can be a patch or invisible change, serum enzymes test normal, anti-myocardial antibody negative.

2. Endocardial fibroelastosis (EFE): The difference between neonatal myocarditis and auricular myocarditis is that arrhythmia is rare. Electrocardiogram can have left ventricular hypertrophy with V5, V6 lead deep Q wave and T wave. Deep inversion, echocardiography showed hypertrophy of the heart wall and interventricular septum, no change in serum enzymology, refractory heart failure, recurrent attacks, X-ray examination showed increased heart shadow, within 1 month after heart failure control No significant reduction.

3. Neonatal hypertrophic cardiomyopathy of mother with diabetes is characterized by: mother has diabetes, most of the babies born are large fetuses, and progressive dyspnea after birth, accompanied by mild cyanosis Respiratory rate 60-80 beats / min, heart rate > 160 beats / min, often galloping, some cases can hear systolic murmur, common hepatic and congestive heart failure, X-ray examination shows increased heart and pulmonary veins mild Hyperemia, electrocardiogram showing left and right ventricular hypertrophy, echocardiography is characterized by a disproportionate thickening of the ventricular septum with the left and right ventricular walls.

4. Glycogenosis (heart type): is due to the lack of glycogen hydrolase caused by the accumulation of glycogen in the heart and other organs, most of which occur in the neonatal period, manifested as loss of appetite, Vomiting, slow growth, followed by difficulty breathing, bruising, irritability, cough and edema, and other symptoms of cardiac insufficiency, occasional heart murmur, the child's tongue is large, often stretched out, muscle weakness, crying small, X-ray examination showed that the heart was spherical, the EC interval showed a shortened PR interval, the ST segment decreased, the QRS complex broadened and the T wave was inverted, and the glycogen increased in the white blood cells of the child.

5. neonatal congenital heart diseases: according to medical history, clinical symptoms and signs, combined with X-ray, electrocardiogram and echocardiography and other performance analysis to make a diagnosis, if necessary, do cardiac catheterization to confirm the diagnosis.

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