Bundle branch reentrant ventricular tachycardia

Introduction to bundle branch reentry ventricular tachycardia Bundlebranchreentry ventricular tachycardia (BBRVT) is a special type of persistent monomorphic ventricular tachycardia caused by large reentry of the Greek-Pu system. basic knowledge Sickness ratio: 0.05% Susceptible people: no special people Mode of infection: non-infectious Complications: sudden death, angina, heart failure

Cause of bundle refractory ventricular tachycardia

(1) Causes of the disease

Usually occurs on the basis of organic heart disease, such as dilated cardiomyopathy accounted for about 50%, the rest can occur in valvular heart disease, ischemic cardiomyopathy, myocarditis, occasionally in hypertrophic cardiomyopathy, Ebstein malformation, and indoor conduction Patients with blockade without structural heart disease (may be those with only He-Poly system lesions), some died of persistent seizures, and autopsy was only degenerative changes in the Xi-Pu system.

(two) pathogenesis

The bundle-return ventricular tachycardia is the only ventricular tachycardia with a clear reentrant ring in the ventricular tachycardia, the His bundle (at least its distal end), the Hip-Pu system and the ventricular muscle are the components of the reentry ring. In part, the bundle branch reentry is a large reentry in the ventricle, which can be expressed in two types: one is the bundle branch block type: the two branches of the left bundle branch are a whole, and the right bundle branch forms a return loop, and its QRS The wave group is a reverse beam branch block pattern; the other type is a branch block type: one branch of the right bundle branch and the left bundle branch together as a forward branch, and the other branch of the bundle branch as a reverse branch, constitutes In the reentry loop, the QRS complex is a retrograde side branch block graph. No matter which type, its excitability can sometimes be reversed through the His bundle and the atrioventricular node. At this time, if the atrium is detached, it can be reversed. Atrium.

The reincarnation of the Greek-Pu system can be divided into the following three types:

1. Type A: typical bundle branch reentry agonism, when stimulating the right ventricle, reverse conduction along the left bundle branch, while forward conduction causes ventricular activation via right bundle branch, ventricular tachycardia caused by type A reentry excitability Speed, its QRS wave is a left bundle branch block graph.

2. Type B: a branching reentry excitatory, the reverse of the excitatory is passed through one branch of the left bundle branch and passed through the other part. Since the ventricular activation is via the left bundle branch system, the QRS wave is a right bundle branch block. In addition, in the normal heart, left ventricular pre-stimulation, V3 is often caused by branch reentry agonism.

3. Type C: The direction of conduction of the reentry loop is opposite to that of type A, that is, the reverse transmission is via the right bundle branch, and the forward excitation is via the left bundle branch. It is a rare type, even if the Hei-Pu system has lesions, type C. It is also rare.

When routine ventricular stimulation is performed in patients with normal indoor conduction, about 50% of patients can induce bundle reentry agonism, but patients with normal indoor conduction have self-limiting bundle branch reentry, and when the He-Pu system has conduction abnormalities, Then the bundle back reincarnation is sustainable.

Bundle branch reentry ventricular tachycardia prevention

1. Active treatment of the primary disease is a fundamental measure to prevent refractory ventricular tachycardia.

2. Set your mind and avoid mental stress; keep indoors quiet and avoid noise and bad stimuli.

3. Comfort the patient with language to establish the patient's determination and confidence in overcoming the disease.

4. Appropriate diet, keep the stool smooth; live a section, beware of exogenous invasion, prohibit alcohol and tobacco.

Biliary refractory ventricular tachycardia Complications, sudden angina, heart failure

Frequent vertigo, syncope, chest pain, severe cases can cause sudden death and other complications; often can induce angina, heart failure and so on.

Bundle branch reentry ventricular tachycardia symptoms Common symptoms Frequent atrial premature beats Montenegro compartment separation chest tightness conduction block tachycardia sudden death chest pain syncope palpitation

Bundle refractory ventricular tachycardia is more common in middle-aged and elderly men with dilated cardiomyopathy. The age is between 50 and 70 years old. When tachycardia occurs, the frequency of tachycardia is faster, generally 200 times/min. Above, at the same time, most patients with refractory tachycardia have severe structural heart disease, and heart function often deteriorates to varying degrees. Therefore, once the bundle branch reentry ventricular tachycardia occurs, Patients often have obvious clinical symptoms such as palpitation, chest tightness, chest pain, darkness, syncope, and even sudden cardiac death.

Inspection of bundled reentry ventricular tachycardia

1. ECG characteristics of bundle-return ventricular tachycardia

Bend refractory ventricular tachycardia manifests as persistent monomorphic ventricular tachycardia with a QRS 0.12 s at onset, often with room septal separation, mostly with left bundle branch block pattern, because of bundle branch reentry dysfunction The most common is QRS with a left bundle branch block pattern, that is, the excitation is reversed to the His bundle by the left bundle branch, and then transmitted to the ventricle by the His-right bundle system. The QRS wave of a few patients has a right bundle branch block pattern. Excited by the right bundle branch back to the His bundle and passed the left bundle to the ventricle, the ventricular rate is not fast, often can be terminated naturally, but easy to relapse.

In conventional electrocardiograms that can induce bundle-return ventricular tachycardia, sinus rhythm often has a performance of indoor conduction delay, often non-specific indoor conduction delay, and can also be expressed as typical left bundle branch resistance. The stagnation or right bundle branch block pattern, this figure is not certain that the side bundle branch is actually blocked, but it is possible that the degree of conduction delay is such that the supraventricular sexual stimuli are transmitted down the contralateral bundle branch to cause the ventricle Excited, in addition, when the forward conduction of one bundle branch is completely blocked, the reverse conduction is still normal, so continuous bundle branch reentry may still occur.

2. Electrophysiological examination features

The bundle-return ventricular tachycardia is characterized by a prolonged HV interval on the His bundle electrogram, and its electrophysiological features are as follows:

(1) QRS time 0.12 s at the time of onset: most of them are left bundle branch block type, and a few are right bundle branch block type, often with atrioventricular septum.

(2) Sinus rhythm: The basic HV interval is extended to some extent, about 60ms or longer.

(3) When tachycardia: There is a His bundle potential (H wave) and/or a right bundle branch potential (RB wave) before each V wave. H is before RB, and the typical sequence is VH-RB. If it is rare C The type of beam branch is folded back, then there is H wave and/or left beam branch potential (LB) in front of each V wave. H is in front of LB, the typical order is VH-LB, and the H-RB interval in tachycardia is shorter than The H-RB interval in sinus rhythm, and the RB-V interval should be RB-V interval in sinus rhythm, if C, the H-LB interval in tachycardia is shorter than sinus rhythm The H-LB interval at the time; and the LB-V interval is the LB-V interval at the time of sinus rhythm.

(4) There must be a critical degree of reverse-transfer delay of the Greek-Pu system to cause tachycardia.

(5) The HV interval when the tachycardia is greater than or equal to the HV interval during sinus rhythm: generally the former is 10 to 30 ms longer than the latter, and rarely exceeds 50 ms.

(6) When tachycardia occurs: The change in HH interval occurs before the VV interval changes.

(7) If the pre-atrial pulsation can cause a block below the His bundle (H): it should be able to terminate the tachycardia.

(8) ventricular premature stimulation can induce or terminate bundle-return ventricular tachycardia.

(9) Ablation of the right bundle can cure the bundle-return ventricular tachycardia.

(10) Atrioventricular separation can often occur.

(11) The electrocardiogram in the intracardiac of each QRS wavefront can be recorded in the Histogram or the right bundle.

Diagnosis and differentiation of bundle branch reentry ventricular tachycardia

diagnosis

Physical examination is mainly a sign of the original heart disease. When the bundle-return ventricular tachycardia occurs, signs of cardiac insufficiency often appear.

1. Persistent bundle branch reentry ventricular tachycardia: QRS time 0.12 s at the time of onset, mostly left bundle branch block pattern, a few showed right bundle branch block pattern.

2. Atrioventricular separation can often occur.

3. During ventricular tachycardia, there is an H wave HV interval between VVs longer than sinus rhythm, which can be extended up to 80ms.

4. Electrophysiological examination is easy to induce ventricular tachycardia.

5. Usually occurs in patients with organic heart disease, more common in dilated cardiomyopathy.

Differential diagnosis

Wide QRS wave tachycardia with atrioventricular septum, His's beam potential (H) before ventricular wave (V), suspected and bundle-return ventricular tachycardia, careful analysis of the bundles of His bundles The order of excitement is the key to making a diagnosis and should be identified with the following tachycardia:

1. Ventricular tachycardia originating in the myocardium: the most common ventricular tachycardia, the reentry loop in the ventricular muscle, most commonly in patients with acute myocardial infarction or ventricular aneurysm.

2. Supraventricular tachycardia with differential conduction in the room.

3. Atrial-branched reentry tachycardia is a ventricular tachycardia caused by reentry excitability of the side of the Mahaim chamber.

4. The QRS wave occurring in the normal heart is left bundle branch ventricular tachycardia or idiopathic ventricular tachycardia.

5. Branch type ventricular tachycardia, the aforementioned type B, branch type ventricular tachycardia can be a simple branch block QRS wave pattern, HV interval at tachycardia is significantly shorter than sinus rhythm HV period.

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