multifocal atrial tachycardia
Introduction
Introduction to multi-source atrial tachycardia Multifocalatrial tachycardia (MAT), also known as chaoticatrialtachycardia (CAT), is a rare and unique atrial arrhythmia that can be found in both adults and children. Sexual tachycardia, but the two are different in terms of etiology. basic knowledge The proportion of sickness: 0.01% Susceptible people: good for children and adults Mode of infection: non-infectious Complications: heart failure
Cause
Multi-source atrial tachycardia
The cause of adults:
This disease is more common in severe illness, the most common causes of elderly patients are as follows:
(1) Chronic obstructive pulmonary disease: 60% to 85% of all cases, of which chronic pulmonary heart disease is the most common, the pathological basis may be obstructive emphysema, the pulmonary artery pressure is too high, secondary right Ventricular hypertrophy and enlargement of the right atrium, ischemia, fibrosis, etc.
(2) heart failure: MAT patients are often accompanied by heart failure, up to 13% to 32%, hypoxia in heart failure and high levels of adrenaline in the blood, may trigger MAT, coronary heart disease patients with congestive heart failure Prone to MAT.
(3) digitalis poisoning: especially pulmonary heart disease with digitalis poisoning, more likely to occur MAT, and often accompanied by varying degrees of atrioventricular block.
(4) Surgery: especially those with a history of surgery with severe complications, such as aspiration pneumonia, Gram-negative bacilli sepsis.
(5) rare causes: such as hypokalemia, pulmonary embolism, hypertensive heart disease, valvular heart disease, sepsis, diabetes, mitral valve prolapse, infection, metabolic disorders or aminophylline can aggravate the condition.
The cause of the child:
(1) The development of the cardiac conduction system is immature: after the birth of the newborn, the heart's conduction system still has a process of continuing to mature. In this process, changes in anatomical histology and pathophysiology can easily lead to arrhythmia and sudden death in infants. The fetus of the heart can occur in the uterus.
(2) Viral myocarditis: A mild and reversible heart attack may occur after infection with Coxsackie virus in the neonatal period, resulting in arrhythmia in some infants.
(3) The basic heart disease of children with multi-source atrial tachycardia can be various congenital heart diseases, cardiomyopathy, rheumatism, etc.: It has been reported that MAT appears after using digitalis, but no digitalis poisoning reaction, After stopping the digitalis, the MAT still exists, so it has nothing to do with digitalis.
Pathogenesis:
It is not clear, some scholars believe that due to multiple impulses in the atrium, alternating impulses, or intraventricular conduction system ischemia, the length of the atrial muscle refractory period is different, and the excitability is reentry within the internode. Mutual interference and fusion lead to MAT. In recent years, it has been found that in the onset of MAT, there is often an increase in plasma catecholamines, which promotes Ca2 accumulation in cardiomyocytes, resulting in excessive Ca2 loading, leading to the formation of triggering activity and MAT, which is considered to be sleeve-disordered. Caused by atrial rhythm, can induce atrial fibrillation.
Prevention
Multi-source atrial tachycardia prevention
1. Actively treat the primary disease, eliminate the predisposing factors, and strictly prohibit alcohol and tobacco.
2. For multi-source atrial tachycardia should be treated with medication to control seizures.
3. Avoid mental stress, moderate work and rest, regular living, and a good diet.
Complication
Multi-source atrial tachycardia complications Complications heart failure
This arrhythmia is complicated by atrial fibrillation. The most common types of coronary heart disease, especially those with myocardial infarction, followed by cardiomyopathy, heart failure, mitral valve prolapse and valvular heart disease. In some cases, it can also occur in patients with no structural heart disease. In these patients with obvious structural heart disease, sudden cardiac death, Asper syndrome, tachycardia, Sudden death can occur if the complications such as heart failure are severe.
Symptom
Multi-source atrial tachycardia symptoms common symptoms acute atrial fibrillation nasal atrial premature beats pale face pale
1. Adults: Most of them occur in the elderly over 65 years old. The symptoms mainly come from the primary disease, while the MAT is mainly characterized by increased heart rate, more than 100 beats/min, up to 150 beats/min, and less than 100. Times / min, the onset of MAT can last for a few minutes, hours, days, or even months, there are reports that last for 9 years, but often lasts until 2 weeks to stop, or become sinus rhythm or become atrial fibrillation, Atrial flutter can be repeated frequently. 64% of patients have atrial contraction before it becomes MAT, and can also be changed from sinus rhythm to MAT. About 55% of MAT can be converted into atrial fibrillation or atrial flutter. Movement, sometimes in the same lead can be recorded before the atrial contraction, MAT, atrial fibrillation or atrial flutter alternately.
2. Children: Clinical features are different from adult patients:
(1) The age of onset is small: most of the months are below 7 months.
(2) There are many patients with respiratory infections at the same time (about 90% of patients).
(3) The general condition is good after the disease control, and no heart failure occurs.
(4) MAT is mostly persistent: it lasts longer, but most of them can disappear within 1 to 4 months.
(5) Electrocardiogram shows that except for MAT, most have a brief atrial flutter, and atrial fibrillation occurs very little.
(6) The efficacy of antiarrhythmic drugs is not obvious.
(7) Good prognosis: the mortality rate is very low.
Symptoms of the child are mainly respiratory symptoms, such as cough, shortness of breath, nasal discharge, irritability, convulsions, pale, other symptoms such as vomiting, convulsions, syncope, etc. Physical examination: obvious arrhythmia, low heart blunt, Lung sounds and so on.
Examine
Multi-source atrial tachycardia
Mainly rely on ECG diagnosis:
1. Adult multi-source atrial tachycardia electrocardiogram features:
(1) There are 3 or more different forms of P' waves on the same lead, and the P' wave is clearly visible. No P' wave is considered to be dominant, that is, there is no dominant pacemaker.
(2) The P'-P' interval has an equipotential line, the P'-P' interval, and the RR interval is completely different.
(3) The P'-R interval varies and varies.
(4) atrial rate of 100 ~ 250 times / min, generally more than 160 times / min, occasionally less than 100 times / min, slower than the usual atrial tachycardia, the attack is mostly not suddenly started, suddenly Termination, very few can also be a sudden onset, abrupt termination.
(5) often accompanied by more obvious atrioventricular block, so the ventricular rate is also slower.
(6) Atrial agitation P' wave can be transmitted to the ventricle, but occasionally P' wave can not be transmitted to the ventricle.
(7) The QRS wave pattern is mostly in the normal range, and even the waveform of the bundle branch block can be used.
Because of the different forms of P' wave, it means the excitement from different parts of the atrium, so it is called multi-source atrial tachycardia. Some scholars believe that it is often developed from multi-source atrial premature contraction.
MAT is often accompanied by other types of atrial arrhythmia, which is one of the characteristics of electrocardiogram, often accompanied by single-source or multi-source atrial premature contraction, atrial fibrillation, atrial flutter, but there is no obvious sequence between them. relationship.
On the electrocardiogram of MAT, the inhibition of sinoatrial node can be seen, for example, sinus arrest, sinus block or even cardiac arrest may occur, which may be caused by overspeed inhibition caused by excessive ectopic atrial rhythm.
2. Characteristics of electrocardiogram in children with multi-source atrial tachycardia: basically the same as adults, but the atrial rate of children is faster, 140-300 beats/min, with an average of 210 beats/min; ventricular rate is 110-200 times. /min, an average of 131 times / min.
Diagnosis
Diagnosis and diagnosis of multi-source atrial tachycardia
According to the medical history, symptoms, signs and electrocardiogram performance can be clearly diagnosed.
Differential diagnosis
1. Atrial fibrillation, atrial flutter: multi-source atrial tachycardia due to its P'-P' interval, RR interval and P'-R interval are often irregular, easy to atrial fibrillation, atrial flutter Confused, but if you can confirm the existence of ectopic P' waves, it is easier to identify.
2. Ventricular tachycardia: When there is a multi-source atrial tachycardia with differential conduction, it can be called ventricular tachycardia. If you can find the ectopic P' wave of each QRS wavefront, then Difficult to identify.
3. Migratory sinus rhythm: Pacing point travels in the sinus node, P wave morphology may change, but PR interval, RR interval is equal, and multi-source atrial tachycardia is completely Wait.
4. Walk around the rhythm between the sinus node and the atrioventricular node: the characteristic is that the P wave from the sinus node is erect, gradually becoming lower to the atrioventricular node, which is negative P wave, PR interval Can be less than 0.12 s, P wave is the dominant heart rhythm.
