Incomplete Blockade of Right Branch: Causes, Symptoms, Diagnosis and Treatment

This electrical conduction system has two branches for each lower chamber of the heart called the branch of the right beam and the branch of the left bundle.

The incomplete blockage of the right branch of the heart is an alteration that affects the electrical system of the heart, the severity of this alteration will depend on whether the occurrence of this alteration is spontaneous or is associated with heart disease.

The heart has an intrinsic system for transferring electrical impulses.

The heartbeat, under normal conditions, begins in the sinoatrial node (NSA), which is a bundle of nerve tissue where the electrical impulse originates, which is known as the natural pacemaker and is located in the upper part of the right atrium.

This impulse diffuses to the atria, causing them to contract, in the same way it reaches the atrioventricular nodule, which is made up of a group of specialized cells, which are located just above the ventricles.

From here the impulse continues through the bundle of His, which are bands of nerve-like fibers that carry electrical signals, propagating the rhythm of atrial contraction to the ventricles.

Divided into two branches: a branch located on the right to stimulate the right ventricle and another branch that stimulates the left ventricle.

But occasionally there is a difficulty in transmitting the impulse to this level, which causes a variation in the pattern of the electrocardiogram called branch block.

This occurs because the stimulation of the cells of the ventricle does not follow its normal course and it contracts.

When this happens, the stimulation of the myocardial cells of the ventricle does not follow the usual path and they contract following an atypical sequence. Although usually stimulation is effective.

This delay in the conduction of the stimulus in the right bundle branch of the ventricle may be complete or incomplete.

When complete blockage of the right branch occurs, the graphic representation of the QRS complex in the electrocardiogram is wider, greater or equal to 120 milliseconds.

On the other hand, when incomplete right bundle branch block occurs, the graphic representation of the QRS complex on the electrocardiogram is less than 120 milliseconds.


This blockade of the right branch of the heart occurs due to dilatation of the right ventricle due to a defect in the wall or atrial septum, which separates the two upper chambers of the heart.

This can be caused by the enlargement of the right ventricle as a result of pulmonary embolism, which is caused by blockage caused by blood clots.

These clots are usually formed in the legs and move through the bloodstream to the down.

This blockage can also be caused without the presence of any other significant heart defect.

There are findings suggesting that the right bundle branch block of the heart may be an alteration that occurred during development in the thickness of the free wall of the right ventricle instead of an anomaly of the conduction system, when the block is presented without the patient present an apparent heart disease.

So this blockage of the right branch of the heart could be of genetic origin.

Symptoms of incomplete right bundle block

The symptoms are presented according to the origin of the blockage of the right branch of the heart and will present the symptoms inherent to the disease that the patient suffers from.

So when there are no causes linked to heart or vascular problems, there is no appearance of symptoms and the patient may suffer for a long time without knowing it.


The most effective test to detect blockage of the right branch of the heart is the electrocardiogram (ECG), since it shows graphically the information about the transmission time, the impulse of the heart, and the possible irregularities.

This cardiac examination allows knowing if the blockage occurs in the left or right branch of the ventricle.

To know the origin of the block, it is necessary to perform echocardiography to rule out the existence of structural problems and to know the degree of involvement of the heart function.

Treatment of incomplete right bundle block

In general, treatment is prescribed only in cases in which there is an associated disease of vascular or cardiac origin.

The blockage of the right branch of the heart is usually asymptomatic and does not require treatment.

In the case of patients with dilated cardiomyopathy, a cardiac resynchronization pacemaker is placed, which stimulates the ventricles and “reproduces” the normal heartbeat in time and place, improving cardiac function and performance.