arrhythmogenic right ventricular cardiomyopathy in children
Introduction
Introduction to arrhythmogenic right ventricular cardiomyopathy in children Arrhythmogenic right ventricular cardiomyopathy (ARVC), also known as arrhythmogenic right ventricular dysplasia (ARVD), is characterized by arrhythmia and right ventricular specific lesions. The name of the disease is not yet unified, called "parchment heart", isolated right ventricular cardiomyopathy, right ventricular dilated cardiomyopathy, arrhythmogenic right ventricular disease, right ventricular dysplasia, arrhythmia type right ventricular cardiomyopathy The International Society of Cardiology (ISFC) Myocardial Pericardial Diseases Task Force called arrhythmogenic right ventricular cardiomyopathy. basic knowledge The proportion of illness: 0.0003% Susceptible people: children Mode of infection: non-infectious Complications: sudden death, arrhythmia
Cause
Causes of arrhythmogenic right ventricular cardiomyopathy in children
(1) Causes of the disease
The cause is unknown and may be related to genetic and infectious factors.
1. Genetic factors: a small number of patients have familial disease, data analysis suggests autosomal dominant inheritance, and family linkage analysis locates disease gene mutations at 14q23-q24, 1q42-q43, 14q12-q22, 2q32.1-q32.2 , 3p23, 17q21.
2. Infectious factors: As a result of chronic inflammatory necrosis of the myocardium, the right ventricular myocardium is fibrotic and replaced by adipose tissue. It has not yet been elucidated. There is a family cluster tendency, 30% has a family history, and the recent study considers it to be due to No. 14 A dominant genetic disease caused by autosomal long arm abnormalities is also thought to be associated with myocarditis caused by infection.
(two) pathogenesis
The main pathological features of the heart are diffuse or localized dilatation of the right ventricular muscle. The myocardium is thinned in the dilated zone. Most of the myocardium is replaced by fibrous adipose tissue. The middle and outer layers of the myocardium are the most common, often involving the right ventricular anterior wall and apex. And the palpebral or inferior wall, histological examination of the right ventricular wall showed lipomatosis and fibrosis, occasionally necrosis and mononuclear cell infiltration, the left ventricle was rarely affected, prominently characterized by a significant decrease in right ventricular myocardial contractility, heart rate The output decreased, the right ventricular end-systolic and end-diastolic volume increased, the right ventricular cavity expanded, and then right heart failure occurred. Some patients developed ventricular arrhythmia in the right ventricle, mostly caused by reentry, often causing sudden death.
Prevention
Pediatric arrhythmogenic right ventricular cardiomyopathy prevention
Focus on genetic counseling and active prevention and treatment of various myocardial inflammation.
Complication
Pediatric arrhythmia complications of right ventricular cardiomyopathy Complications sudden death arrhythmia
Right heart failure, arrhythmia, serous effusion, sudden death can occur.
Symptom
Pediatric arrhythmogenic right ventricular cardiomyopathy Symptoms Common symptoms Palpitation tachycardia Arrhythmia Right heart failure syncope Heart enlargement Chest tightness Cholesterol syndrome Sudden death
Can occur in the fetal period, to the onset of adolescence, the disease occurs in men, more than 80% of the patients diagnosed before the age of 40, males, the average age of good hair is about 30 years old, clinical manifestations and lesions, The location and age of onset are related to three types of symptoms:
1. Right heart failure: more common in infants,
2. Arrhythmia: Repeated episodes of left bundle branch block ventricular arrhythmia, patients often have palpitations, chest tightness, black Mongolian and other discomfort during exercise, or no symptoms, confirmed by accidental ventricular arrhythmia Repeated ventricular tachycardia can lead to syncope or sudden death. Some patients have sudden death as the first performance, especially in those under 35 years old and athletes, which are easily induced during emotional or competitive sports.
3. The heart is enlarged and asymptomatic: There are many abnormalities in the physical examination. Some patients have enlarged heart, and the third, fourth heart sound and the second heart sound can be heard.
Examine
Pediatric arrhythmia right ventricular cardiomyopathy examination
1. General routine inspection: Mostly normal.
2. Endomyocardial biopsy: Histomorphology (fibrous adipose tissue replacement) features diagnostic value, but the right ventricular free wall (typical lesions, usually with no interventricular septum) biopsy myocardial perforation increased risk, traumatic Check, it is not always possible to get the lesion,
1. X-ray examination: Some patients may have heart enlargement on X-ray. Marcus et al reported that 16 of 22 patients had enlarged heart, the heart was often spherically enlarged, and the pulmonary vascular shadow was reduced.
2. Electrocardiogram: ECG shows right atrial hypertrophy (II lead shows high P wave) and right ventricular low voltage, sinus rhythm, Vl lead QRS wave group interval 110ms is its characteristic, its sensitivity is 55%, specific Sexual 100%, QRS complex interval in V1 lead is longer than in I and V6 leads to extend right indoor conduction delay), about 30% of patients with ARVC in V1 lead visible QRS complex has a discrete wave, called It is an epsilon wave.
(1) Electrocardiogram sinus rhythm has the following characteristics:
1 is incomplete or complete right bundle branch block.
2TII, III, aVF and TV1-4 are inverted.
The 3 part of the electrocardiogram QRS wave has a small separation wave, especially the V1 lead, which is called wave. This low amplitude potential represents delayed ventricular activation in a certain part of the right ventricle.
4 ventricular premature contraction was left bundle branch block type.
5 a few have supraventricular arrhythmia and atrioventricular node dysfunction.
(2) Ventricular tachycardia episode: QRS wave is left bundle branch block type, and the ventricular rate is 200 times/min, which is persistent or non-sustainable.
3. Signal average electrocardiogram: The signal average electrocardiogram is used to trace the ventricular late potential (especially patients with diffuse lesions) with diagnostic reference value.
4. Echocardiography and radionuclide angiography: Echocardiography can show right ventricular structural and functional abnormalities, measuring right ventricular / left ventricular end diastolic diameter ratio greater than 0.5 (except for those under 6 months), to diagnose the sensitivity of ARVC 86%, specificity of 93%, often disappeared or reduced right ventricular regional motion, radionuclide angiography showed right ventricular morphology and wall motion abnormalities, echocardiography is conducive to diagnosis, visible:
(1) The right ventricle is enlarged, and the ratio of the right ventricle to the left ventricular diameter is increased, mostly in the range of 0.5 to 1.5 (normal 0.33 ± 0.06).
(2) Diastolic local bulging and systolic dyskinesia in the inferior wall of the basal part of the tricuspid valve.
(3) Isolated expansion of the right ventricular outflow tract.
(4) The left ventricle is generally normal.
5. Magnetic Resonance Imaging (MRI): Qualitative and localized analysis of tissue components (fatty tissue, fibrous tissue) in cardiac tissue, although highly specific, but less sensitive (especially in early cases), magnetic resonance imaging In addition to observing the structure and function of the ventricle, imaging is the most effective method for non-invasive measurement of myocardial infarction. It can be diagnosed at an early stage and may replace the endocardial myocardial biopsy.
Diagnosis
Diagnosis and differential diagnosis of arrhythmogenic right ventricular cardiomyopathy in children
Typical cases are diagnosed by clinical symptoms, electrocardiogram and echocardiography. The diagnosis of this disease should be based on autopsy or surgery. Histologically, most of the right ventricle is replaced by fibrous adipose tissue. However, Most cases are not possible, currently using the diagnostic criteria developed by the European Society of Cardiology in 1994, including the main and minor criteria for structure, function, histology, electrocardiogram, arrhythmia and genetics, in accordance with the two main criteria of the different groups or A major standard plus 2 secondary criteria, or 4 secondary criteria, can diagnose the disease.
Infants and young children should be associated with Ebstein malformation, pulmonary venous venous return to distinguish between right ventricular involvement of congenital heart disease and Uhl disease, the latter is a right ventricular malformation, the right ventricular wall completely lacks myocardial tissue, the heart and the outer membrane are stuck together. Known as the "parchment-like heart", heart failure occurs in infancy and is rarely caused by exercise-induced death.
