Atrial flutter in children
Introduction
Introduction to pediatric atrial flutter Atrial flutter (AF) is referred to as atrial flutter. It can be caused from the fetal period to all age groups. Although it is rare, it is a serious condition and should be treated promptly. Unlike adults, pediatric atrial flutter is more common than atrial fibrillation. Atrial flutter is a rapid, regular ectopic atrial arrhythmia with typical serrated atrial waves on the ECG. The atrial rate is about 350-600 beats/min in infants and about 250-350 beats/min in childhood. . Flutter and tremor are rare in children, but because they often cause severe hemodynamic changes or even death, they are pediatric emergency and need urgent treatment. basic knowledge The proportion of illness: the incidence rate is about 0.005%, more common in children with myocarditis Susceptible people: children Mode of infection: non-infectious Complications: cardiogenic shock, dilated cardiomyopathy, sudden death
Cause
Pediatric atrial flutter
Cause
Atrial flutter can occur in normal heart. The pediatric cupping network is more common in infants, newborns, and even fetal babies. The mechanism may be due to imperfect development of the atrial muscle and conduction system. Impulsive causes of reentry in the atrial muscle or through the atrioventricular bypass. Most children have structural heart disease, mainly congenital heart disease, especially in children with aortic dislocation after surgery by Mustard or Senning. Others have myocarditis, dilated cardiomyopathy, rheumatic heart disease, sick sinus syndrome, and extra-cardial factors such as digitalis poisoning, hypokalemia and other electrolyte disorders. Garson et al reported that 380 patients with AF in collaboration with 11 hospitals had an age of onset of 1.1 to 25 years (median 10.3 years), and congenital heart disease accounted for 81%, mainly with aortic dislocation, single ventricular complex malformation atrial septal defect, Faro quadruple Disease, atrioventricular access, etc., 75% of patients had at least one heart surgery before AF occurred. Intracardiac surgical trauma, the formation of scar tissue may provide the basis for the generation of reentry excitability.
Pathogenesis
1. Classification
(1) Electrocardiogram examination: Clinically, according to ECG examination, it is divided into typical atrial flutter and atypical atrial flutter. The atrial flutter wave of typical atrial electrocardiogram II, III, aVF and lead is a negative sawtooth wave, also known as common type; On the contrary, atrial flutter ECG II, III, aVF, and lead atrial flutter waves are positive waves, also known as uncommon types.
(2) Clinical electrophysiological examination: According to the response of atrial flutter to atrial pacing and the frequency of atrial flutter, it is divided into type I atrial flutter and type II atrial flutter health search. Type I atrial flutter is slower, can be stopped by rapid atrial pacing, and type II atrial flutter is faster and cannot be stopped by rapid atrial pacing.
(3) New classification: Recently, Scheinman abroad proposed a new classification method based on the successful anatomical structure of the radiofrequency catheter ablation site and the reentry loop of the atrial flutter. 1 The right atrial flutter: tricuspid annulus - lower The isthmus of the vena cava serves as a key part of the atrial foci reentry loop and an isthmus-independent atrial flutter (including scar atrial flutter after surgery). 2 left atrial flutter: atrial flutter in the mitral annulus.
2. Electrophysiological mechanisms
The mechanism of atrial flutter is currently accepted by most scholars. The most common atrial flutter health search is due to intraventricular reentry, and the location is mostly in the right atrium. The typical reversal of type I atrial flutter is that the interatrial septum is the tail direction, and the right atrium free wall is the head-to-tail direction, that is, the counterclockwise direction; the type II atypical atrial flutter is the clockwise direction. There is a slow conduction zone behind the back of the ring. It has been confirmed by electrophysiology and surgery that the slow conduction zone is mostly located in the isthmus around the coronary sinus, inferior vena cava and tricuspid annulus. In addition, atrial conduction scars can also form a slow conduction zone after congenital heart disease surgery and cause reentry.
Prevention
Pediatric atrial flutter prevention
See congenital heart disease; prevention and treatment of electrolyte imbalance and acid-base imbalance, active treatment of primary disease, such as various gastrointestinal disorders, uremia, rheumatic fever, Kawasaki disease, nervous system factors, hypothermia, anesthesia and drug poisoning (such as digitalis poisoning, etc. Arrhythmia caused by etc; improved surgical methods to reduce postoperative atrial flutter caused by trauma or scarring.
Complication
Pediatric atrial flutter complications Complications, cardiogenic shock, dilated cardiomyopathy, sudden death
Can be complicated by heart failure, cardiogenic shock, dilated cardiomyopathy, and even sudden death.
Symptom
Pediatric atrial flutter symptoms common symptoms tachycardia fatigue convulsions palpitations arrhythmia heart sounds low blunt pulse miss heart failure dizziness dying
The symptoms and signs of the child are related to the severity of heart disease and the rate of ventricular rate. Lighter can be asymptomatic. In severe cases, heart failure, syncope, convulsions, cardiogenic shock, etc., such as fast heart rate, long duration, and onset Frequent atrial flutter can cause tachycardia dilated cardiomyopathy. When physical examination, the heart sounds are low and blunt, and the intensity is different. There may be pulse leakage. There are two types of clinical manifestations of neonatal atrial flutter:
Congenital chronic atrial flutter
More often appear after birth, children can be tolerated, the general treatment is invalid, can be self-healing within 1 year.
2. Paroxysmal atrial flutter
More often occurs weeks or months after birth, the application of anti-arrhythmia drugs such as digitalis effective, but easy to relapse, normal heart newborns and infants AF often persistent, a few paroxysmal, atrioventricular conduction can be 1 : 1, the ventricular rate is extremely fast, up to 250 times / min, prone to rapid arrhythmogenic cardiomyopathy, heart failure, such as atrioventricular conduction is 2:1 or 3:1, children can often tolerate, symptoms are not Obviously, more than 1 year old self-resolved, prognosis is good, AF with organic heart disease, mostly dizziness, palpitations, fatigue, severe heart failure, syncope or sudden cardiac death, the prognosis depends on heart disease Severity, left atrial size and drug treatment can control the onset of AF. Garson reported 380 cases of AF, followed up for 0 to 13 years, the mortality rate was as high as 16.6%, most of them were sudden death, and considered dilated cardiomyopathy and complex heart malformation The left atrial enlargement has an internal diameter of 150% of normal high value and AF, and the patient mortality rate is difficult to control.
Examine
Pediatric atrial flutter
Light examination is generally normal, severe cases may have hypoxemia, acidosis and so on.
1. ECG characteristics
(1) The frequency of F wave is 350-500 times/min, which is wavy or serrated, and there is no equipotential line between F waves. The F wave of II, III, aVF, V3R, V1 leads is more obvious in a few infant cases, F The wave is not obvious, and an esophageal atrial electrogram should be used to assist in the diagnosis.
(2) Atrioventricular conduction ratio: infant AF can have 1:1 atrioventricular conduction, most of which are 2:1 to 3:1 conduction, 4:1 atrioventricular conduction is less common, mostly occurs with digoxin or propranolol After that.
(3) QRS wave: the shape is mostly normal, occasionally indoor differential conduction, QRS wave wide deformity.
2. Chest film
On the right, the heart is enlarged and the lungs are blocked.
3. Echocardiography
Abnormal changes such as cardiac malformation and decreased myocardial contractility can be found.
Diagnosis
Diagnosis and diagnosis of atrial flutter in children
The clinical diagnosis of atrial flutter is mainly based on the ventricular rate of 150 to 250 beats / min, regular, jagged, consistent atrial wave or a history of structural heart disease, ECG diagnosis is still a reliable basis for diagnosis, type I The atrial rate of atrial flutter is 250-350 times/min, more than 300 times/min, the P wave disappears with a sawtooth-like F wave, and the II, III, aVF lead is a significant negative wave, the equipotential line disappears, the atrioventricular 2:1, even 1:1 conduction, ventricular rate 150 ~ 250 times / min, II type atrial flutter rate more than 350 times / min.
When the diagnosis of conventional electrocardiogram is unknown, special examinations such as dynamic electrocardiogram, transesophageal atrial pacing can be used to record esophageal P waves. When highly suspected, interventional intracardiac electrophysiological examination can also be performed.
Differential diagnosis includes sinus speed, paroxysmal atrial tachycardia, atrial fibrillation and ventricular tachycardia.
