Atrioventricular junction escape

Introduction to the atrioventricular junction AVjunctionalescapebeats is due to the frequency of sinus node impulses slowing down below the frequency of potential pacemakers in the atrioventricular junction or conduction dysfunction. The sinus node impulse cannot reach the pacemaker site. Potential pacing points are removed. Extremely generated escape. Under physiological conditions, the atrioventricular junction does not exhibit self-discipline, but has a potential pacing function, so it is called a potential pacemaker. If the frequency of sinus node release impulses is significantly lower, and slower than the natural frequency of potential pacemakers in the atrioventricular junction; or due to conduction disorders, the sinus node impulses cannot reach the potential pacemakers at the atrioventricular junction. Potential pacing points located at the junction of the atrioventricular compartment can manifest an intrinsic pacing function that induces AVjunctionalescapebeats. The ECG of the atrioventricular borderline escape appears as a normal QRS complex after an interval longer than the normal PP interval. At this time, the retrograde P wave induced by the impulse of the potential pacemaker can be missing or located before the QRS complex. Or after. In addition, it can also be seen that the sinus P wave is not transmitted to the ventricle. When the atrioventricular junction escape occurs continuously, the rhythm, that is, the atrioventricular junction rhythm (AVjunctional rhythm), the frequency of the latter is 40 to 60 times / minute. Atrioventricular borderline escape or rhythm is associated with increased vagal tone, significant sinus bradycardia, or atrioventricular block. It is one of the physiological mechanisms of prevention of ventricular arrest, usually without treatment, if necessary Pacing treatment is also available. basic knowledge The proportion of sickness: 0.01% - 0.02% Susceptible people: no specific population Mode of infection: non-infectious Complications: syncope, hypotension

Incidence of atrioventricular junction

Because the sinus node impulse frequency slows down below the frequency of the potential pacemaker in the atrioventricular junction or the conduction sinus node impulse can not reach the pacemaker site, the potential pacemaker point depletion generates an escape.

Atrioventricular junctional escape prevention

Escape rhythm in the junction area and escape rhythm in the junction area is a physiological compensatory mechanism. When it appears, it is necessary to actively search for the primary disease that causes escape in the junction area and escape rhythm in the junction area, ascertain the cause and actively treat the original disease. The cause of the disease is a fundamental measure to prevent such arrhythmia.

Atrioventricular junctional escape complications Complications, syncope, hypotension

Long-term handover escape rhythm, when the ventricular rate is too slow, complications such as syncope and hypotension may occur.

Atrioventricular junction area escape symptoms common symptoms atrial escape pulse rhythm acceleration escape

The frequency of atrioventricular junction escape is usually 35-60 beats per minute. The electrocardiogram showed a normal QRS complex after a pause longer than the normal PP interval. The P wave was missing, or the retrograde P wave was before or after the QRS wave. In addition, the sinus P wave that was not transmitted to the ventricle was also seen. .

Examination of atrioventricular junctional escape

ECG: Frequency is 35-60 times / minute. The P wave disappears or the retrograde P wave exists before or after the QRS complex, and the sinus P wave that does not pass down the ventricle is seen.

The ECG characteristics of the junctional escape are as follows:

A QRS complex appears after a pause that is longer than a basic cardiac cycle.

The shape of the wave is the same as that of the atrial descendant, and it can be wide and deformed if it is accompanied by indoor differential conduction.

The P wave before and after the wave group can have the following performances:

1 The sinus P wave appears before, during and after the QRS complex, and the interference phenomenon occurs. The PR interval before the Q RS group is <0.12 seconds; in the QRS group, the QRS group is deformed; in the QRS wave After the group, there is an upright P wave on the ST-T.

The retrograde P` wave can be seen before and after the 2QRS wave group. The P` wave has a P'-R interval <0.12 seconds before the QRS complex and <0.20 seconds after the PP' interval.

There is no P` wave visible before and after the 3QRS wave group. At this time, the QRS wave group shape should be normal, so that the diagnosis of atrioventricular junction escape can be made.

4 can have atrial fusion wave.

The electrocardiogram of the atrioventricular escape rhythm is as follows:

Three or more consecutive escapes are called atrioventricular junctional stroke rhythms with a frequency of 40 to 60 beats/min.

Diagnosis and differentiation of atrioventricular junctional escape

diagnosis

Diagnosis can be based on medical history, clinical symptoms, and laboratory tests.

Differential diagnosis

1. Identification with atrial premature contraction: The characteristics of atrial electrical stroke and atrial premature contraction are very similar, except that atrial escape is more likely to occur after a longer interval (more intermittent than the normal sinus cycle). And atrial premature contractions occur in advance (intermittent intervals shorter than the normal sinus cycle).

2. Identification of arrhythmia with atrial parallelism: The frequency of the atrial rhythm P' wave is slower than the sinus, usually 35 to 55 times/min. Ectopic P' has no fixed interphase, but the long spacing between ectopic P is a multiple of short spacing. This is because the atrial parallel rhythm has a protective afferent block around the ectopic pacemaker, and the external impulse cannot invade the ectopic pacemaker and re-regulate the rhythm. The atrial escape rhythm frequency is 50 ~ 60 times / min, very regular, occasionally irregular. Because there is no protective afferent block around the ectopic pacemaker of atrial escape, once the frequency of sinus impulse exceeds the atrial escape frequency, the atrial ectopic pacemaker is suppressed and becomes the ineffective pacing point. Sexual rhythm.

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