Right bundle branch block

Introduction The right bundle branch block is divided into complete right bundle branch block and incomplete right bundle branch block according to the degree of block. The right right bundle branch block is that there is a problem with the right bundle branch to the right ventricle. The bioelectrical signal cannot be transmitted directly to the right ventricle, but it does not matter. The electrical signal can be transmitted from the left ventricle, only the right ventricular contraction. Its late. Complete right bundle branch block does not necessarily have extensive myocardial damage. If there is no other organic heart, it is often not important. Common diseases are due to rheumatic heart disease, congenital atrial septal defect, and also in the lung. Heart, coronary heart, cardiomyopathy, etc. If you have a medical examination to confirm that there is no organic heart disease, incomplete right bundle branch block, usually no pathological significance. Since there is no pathological significance, a normal healthy lifestyle will not affect it.

Cause

The cause of right bundle branch block:

1. Myocardial inflammation is most common for a variety of reasons, such as rheumatic, viral myocarditis and other infections.

2. The vagus nerve is excited, often manifested as transient atrioventricular block.

3. Drugs, such as digitalis and other antiarrhythmic drugs, most of the discontinuation of the drug, the atrioventricular block disappeared.

4. Various organic heart diseases such as coronary heart disease, rheumatic heart disease and cardiomyopathy.

5. Hyperkalemia, uremia, etc.

6. Idiopathic conduction system fibrosis, degeneration, etc.

7. Trauma, accidental injury during cardiac surgery or affecting atrioventricular conduction tissue can cause atrioventricular block.

an examination

Related inspection

Cardiovascular dynamic electrocardiogram (Holter monitoring)

Examination and diagnosis of right bundle branch block:

Patients with atrioventricular block were often asymptomatic, and the first heart sound of the apex was weakened during auscultation. This was due to the prolongation of the PR interval and the closure of the atrioventricular valve leaf at the beginning of ventricular contraction.

Patients with second-degree type I atrioventricular block may have a heartbeat sensation. Patients with second-degree type II atrioventricular block are often fatigued, dizzy, fainting, convulsions, and cardiac insufficiency, often developing to completeness in a relatively short period of time. Atrioventricular block, whether the heart rhythm is auscultated or not, depends on the change in the proportion of atrioventricular conduction.

The symptoms of complete atrioventricular block depend on whether the ventricular arrhythmia and ventricular rate and the basic condition of the myocardium are established. If the ventricular arrhythmia is not established in time, ventricular arrest occurs, and the autonomous rhythm is higher, such as the His bundle. Below, the ventricular rate is as fast as 40-60 beats / min, the patient may be asymptomatic, the ventricular autonomous rhythm point of the double bundle branch lesion is very low, the ventricular rate is slower than 40 beats / min, and cardiac dysfunction and cerebral ischemia may occur. Syndrome (Adams-Stokes, Syndrome) or sudden death, slow ventricular rate often causes increased systolic blood pressure and pulse pressure widening.

Differential diagnosis

Symptom identification of the right bundle branch block is confusing:

Differential diagnosis of right bundle branch block: clinically need to identify physiological or pathological second degree atrioventricular block, must be combined with clinical examinations and causes and clinical manifestations to make analysis.

1, physiological atrioventricular block: Most people with normal atrioventricular conduction function, rapid atrial pacing can induce Venturi-type atrioventricular block. Atrial pacing graded pacing and paroxysmal atrial, atrial flutter, borderline tachycardia, because the atrial cycle is significantly shorter than the effective refractory period of the atrioventricular node, resulting in some supraventricular sexual excitement can not be transmitted to the ventricle And atrioventricular block. This is an interference phenomenon of physiological atrioventricular block.

2, pathological atrioventricular block:

(1) The influence of vagal tone and the effect of drugs can cause atrioventricular block. The movement or use of atropine can eliminate the influence of vagal tone, significantly improve the function of atrioventricular node, and the atrioventricular block disappears. Clinically, many drugs such as digitalis drugs, calcium antagonists, and central and peripheral sympathetic blockers can cause atrioventricular block.

(2) Atrioventricular block in acute myocardial infarction is more common than acute anterior myocardial infarction, and the mechanism of atrioventricular block is related to the increased ischemic and significant vagal tone. Inferior myocardial infarction with atrioventricular block often presents intermittent features, and the QRS morphology is normal and can disappear after a few days. Acute anterior wall myocardial infarction is associated with type II atrioventricular block, and the mechanism of its blockade is related to the extensive infarction range leading to conduction bundle branching. Dynamic electrocardiogram showed that type II atrioventricular block in anterior myocardial infarction was often accompanied by intermittent or persistent bundle branch block (left and right bundle branch or branch block pattern). This type of block is prone to develop complete atrioventricular block.

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