Atrial escape and atrial escape rhythm
Introduction
Introduction to atrial escape and atrial escape rhythm Atrial escape is a physiological compensatory mechanism, and three or more atrial escapes constitute atrialescaperhythm. When the sinus node is inhibited, the sinus rhythm can occur, and the atrial escape disappears. basic knowledge The proportion of illness: 0.002% Susceptible people: no special people Mode of infection: non-infectious Complications: sinus bradycardia atrioventricular block
Cause
Atrial escape and atrial escape rhythm
(1) Causes of the disease
1. Occasionally appear in healthy people.
2. Atrial escape and escape rhythm is a rare passive ectopic heart rhythm, mostly in severe sinus bradycardia, temporary inhibition of sinus node, sinus block, sinus arrest, atrioventricular conduction Blocking, atrial premature contraction occurs after a long interval, lower atrial rhythm, such as coronary sinus arrhythmia occurs in digitalis poisoning, acute myocardial infarction, acute rheumatic fever, severe respiratory failure, and increased vagal tone, Left atrial escape rhythm is more common in a variety of organic heart disease, but healthy people can also appear.
(two) pathogenesis
The sinoatrial node is the highest pacemaker of the heart. It has the highest self-discipline in all myocardial autonomous cells. In addition to the sinoatrial node, there are many potential pacemakers in the heart. There are three main places, the atrium and the atrioventricular junction. And the ventricle, each has its own fixed frequency. In many cases, the potential pacemaker is suppressed by the faster impulse of the highest pacing point sinus node, can not control the ventricle, when the sinus node is suppressed, the frequency is reduced , or due to sinus conduction block, sinus arrest, atrioventricular block, etc., when sinus agitation can not be transmitted, the potential pacemaker point is passive impulse, so that the heart avoids excessive pauses, this It is a physiological compensatory mechanism. When a bradycardia is delayed, a passive ectopic beat is delayed after a long interval. The pacing point is called atrial escape in the atrium, and the atrioventricular junction is called the atrioventricular junction. Sexual escape, in the ventricle, is called ventricular escape, if the escape is 3 or more times, it becomes the escape rhythm, usually slower than the sinus frequency, and the escape rhythm is slightly faster than the sinus heart rate. Accelerated escape rhythm or non-paroxysmal heartbeat Speed.
Prevention
Atrial escape and atrial escape rhythm prevention
Atrial escape and atrial escape rhythm are a physiological compensatory mechanism. When they appear, they should actively search for the primary disease that causes atrial escape and atrial escape rhythm, identify the cause, and actively treat the original disease. The cause of the disease is a fundamental measure to prevent such arrhythmia.
Complication
Atrial escape and atrial escape rhythm complications Complications sinus bradycardia atrioventricular block
Patients often have many complications, sinus bradycardia, sinus node temporary sinus block, sinus arrest, atrioventricular block, and atrial premature contraction abnormalities. Lower atrial rhythm, coronary sinus rhythm, acute myocardial infarction, acute rheumatic fever, severe respiratory failure, increased vagal tone, left atrial escape rhythm, various organic heart disease, but healthy people can also appear.
Symptom
Atrial pacing and atrial pacing rhythm symptoms common symptoms conduction block atrial escape rhythm acceleration arrhythmia
Atrial pacing and atrial escape rhythm are often secondary to those with atrioventricular block, which can occur at any time of the day. In the absence of atrioventricular block, sinus node pacing and conduction function are good, It is rare in activities and waking hours, mainly in the evening sleep or lunch break.
Examine
Examination of atrial escape and atrial escape rhythm
Mainly rely on ECG diagnosis, ECG has the following performance:
1. ECG characteristics of atrial escape
(1) ECG characteristics of typical atrial escape:
1 After a long interval, one or two atrial escape P' waves are delayed, and the morphology is different from the sinus P wave.
The 2P'-R interval is greater than 0.12 s, or slightly shorter than the sinus PR interval.
The 3QRS-T wave group is the same as the sinus heart beat.
(2) A detailed description of the typical ECG characteristics of atrial escape:
1 Because atrial escape is a passive rhythm, it must be delayed after a long interval.
2 The length of the general atrial escape cycle is 1.0 to 1.2 s, and the frequency is 50 to 60 times/min.
The P' wave of the 3 atrial escape is different from the sinus P wave: if the P' wave originates from the upper part of the atrium, the P' wave of the II, III, aVF lead is erect or bidirectional; if originated from the lower part of the atrium, II, III The P' wave of the aVF lead is inverted. If the P' wave is inverted at the I, V5, and V6 leads, and the V1 lead is erect, it originates from the left atrium.
The P' wave of 4 atrial escape: it can be single-source or multi-source, the latter has different P' wave morphology on the same lead, while the single-source P' wave is basically the same.
The 5P'-R interval may be shorter than the sinus PR interval in some cases. The reason may be that the atrial beat of the escape is delayed, and the atrioventricular node has a long recovery period, so the rate of agitation conduction increases. However, the P'-R interval is usually 0.12 s.
The QRS-T wave pattern transmitted by the 6-room escape was the same as that of the sinus rhythm.
7 lack of afferent block: once the sinus heart rate > 60 beats / min, the pace of atrial escape is suppressed.
(3) Characteristics of a slow atrial escape:
1 In the sinus conduction block, the frequency of sinus node release is abnormally slow, the atrial pacing point can still emit 1 or 2 impulses when the self-discipline has been reduced, forming a slow atrial detachment. Beat, a passive arrhythmia.
2 After a long interval, 1 to 2 episodes of atrial P'-QRS-T wave group were delayed, the escape cycle was >1.20 s, and the frequency was <50 times/min.
2. ECG characteristics of atrial escape rhythm
1 The escape cycle is constant: the potential pacemaker is impulsive at the natural frequency, but the escape or escape rhythm from the same starting point, the period is fixed, and the atrial escape rhythm is generally 50 to 60 times / Min.
2 Delayed appearance: The escape period is always greater than the sinus cycle or the basic rhythm cycle, because the escape is necessarily delayed, and the escape rhythm is always slow.
3 start phenomenon: Because the pace of pacing is less affected by autonomic factors, the escape rhythm is regular, but sometimes the first few stroke cycles of escape rhythm are longer, the frequency is slower, and the frequency is faster. The cycle is shortened, and then a fixed escape period, a rhythm rule, is presented, which is a step phenomenon or a starting phenomenon.
4 no afferent blockade when the sinus frequency is lower than the escape frequency when the bradycardia is slow, the escape or escape rhythm occurs; if the sinus frequency is faster than the escape frequency, the escape is suppressed and disappears, this is due to The ectopic beat point is not caused by afferent block protection.
(1) Typical ECG characteristics of atrial escape rhythm:
1 There are 3 or more atrial escapes in succession.
The morphology of the 2P' wave may be single-sourced or multi-sourced, unlike the sinus P-wave.
3 atrial escape rhythm frequency is 50 ~ 60 times / min, very regular, but occasionally irregular.
4P'-R interval > 0.12 s.
The 5QRS-T wave group is the same as the sinus.
6 can be combined with atrial fusion waves.
(2) A detailed description of the typical ECG of atrial escape:
The morphology of the 1P' wave is determined by the location of the atrial escape rhythm ectopic pacemaker.
A. Originated from the upper part of the right atrium: the direction of ectopic pacemaker activation is right, back, up, pointing left, front, down, P' wave vector is in the transverse plane, and the frontal surface is similar to the sinus P-ring vector. Therefore, the P' wave morphology on the electrocardiogram is similar to the sinus P wave.
B. Originated from the lower part of the right atrium: the direction of ectopic pacemaker excitation is from the right, the lower, the left, the upper, the P-wave vector loop in the lateral plane, the frontal plane and the atrioventricular junction area retrograde P ring The vector is similar, on the electrocardiogram I, aVL, II, III, aVF lead P' wave inversion, aVR lead P' wave erect, but P'-R interval is greater than 0.12s, it is believed that originated from the lower right atrium The heart rhythm, called coronary sinus rhythm, is based on the electrocardiogram of the catheter placed in the coronary sinus and the position of the esophageal lead electrocardiogram equivalent to the coronary sinus. The P' wave of the above characteristics can be recorded. The above figure can be recorded in the lower left atrium and in the lower right atrium. Therefore, it should be called the lower atrial rhythm.
C. can originate in the left atrium, manifested as left atrial rhythm.
The 2 atrial escape rhythm may not be uniform: the P'-P' interval may differ by more than 0.12 s, which is caused by the instability of the rhythm issued by the ectopic pacemaker of the atrial escape.
3 When the atrioventricular block is combined, the P'-R interval is >0.20s: or the leakage is present. When the WPW is combined, the P'-R interval is <0.12s.
4 room escape rhythm can start to appear.
5 When the P' wave is multi-sourced, the morphology can be different, which is called multi-source atrial escape rhythm.
(3) Characteristics of a slow atrial escape rhythm:
1 The mechanism of occurrence is the same as that of a slow atrial escape.
2 The slow atrial escape is 3 or more consecutive: frequency <50 times/min.
3 P'-R interval > 0.12 s.
Diagnosis
Diagnosis of atrial escape and atrial escape rhythm
According to the medical history, symptoms, signs and electrocardiogram performance can be clearly diagnosed.
1. The characteristics of atrial pacing and atrial premature contraction to distinguish between atrial escape and atrial premature contraction are very similar, except that atrial escape usually occurs in a longer interval (more normal than the normal sinus cycle) After the interval), the atrial premature contraction occurred earlier (intermittent than the normal sinus cycle).
2. Atrial escape rhythm and atrial parallel rhythm identification Atrial parallel rhythm P' wave frequency is slower than sinus, often 35 ~ 55 times / min, ectopic P' no fixed interval, but The long distance between ectopic P is a simple multiple of short-spacing because the atrial parallel rhythm has a protective afferent block around the ectopic pacemaker, and the external impulse cannot invade the ectopic pacemaker. The rhythm is reorganized, and the atrial rhythm frequency is 50-60 beats/min. It is very regular and occasionally irregular. Because of the ectopic pacemaker of atrial escape, there is no protective afferent block around. The frequency of sinus impulse exceeds the frequency of atrial escape, which makes the atrial ectopic beat point inhibit, becomes an ineffective pacemaker, and has sinus rhythm.
