Bundle Branch Block

What is a Bundle Branch Block?

Bundle branch block is a condition characterized by an obstruction or delay in the involuntary electrical action of the heart. More specifically the electric impulses that make your heart beat when it is supposed to. This interruption usually affects the impulses going to only one side of your heart. Usually, it is the bottom ventricles of the heart affected.

Most patients with this disorder find that it is more difficult for their heart to pump enough blood to allow the circulatory system to function properly. This disorder requires medical treatment to prevent it from becoming more severe over time.

What are the Symptoms of a Bundle Branch Block?

Unfortunately, most patients with this disorder do not experience any symptoms. Many do not even know they have the condition until their doctor points it out.

Symptoms include

  • Fainting
  • Vertigo (a feeling like fainting)

The cause of a bundle branch block can be different from person to person. The condition can also develop without any known cause.

In order to determine whether you have this disorder, your doctor will request an electrocardiogram and echocardiogram. These tests can pinpoint the exact problem and location of your heart problem. It can also help determine whether or not there is an underlying cause that needs to be treated.

Your doctor may also order a series of blood work to determine whether there are any markers in your blood that indicate heart disease.

Bundle Branch Block Causes

Electrical impulses in your heart muscle signal it to contract. These impulses travel through the heart along a path that includes the right and left nerve bundles in the heart. If one or both bundles are damaged in a heart attack, the electrical impulses become erratic and your heart beats abnormally.

Bundle branch blocks have a variety of causes, depending on whether the left or right bundle branch is damaged. Causes of left bundle branch block include heart disease, as well as a thick, stiff or weak heart muscle (cardiomyopathy). Alternately, the left bundle branch can be blocked due to a viral or bacterial infection in the heart (myocarditis). High blood pressure is another leading cause.

Right bundle branch blocks have more potential underlying causes, which include congenital heart defects like an atrial septal defect, a heart attack, viral or arterial infection, high blood pressure or a blood clot in the lungs (pulmonary embolism). When the above underlying causes occur, the risk of bundle branch block increases greatly.

How is a Bundle Branch Block Treated?

The majority of patient with bundle branch block do not have any symptoms. These patients do not require any treatment. However, if the condition was caused by underlying heart disease, it is important to treat this disorder.

Treatment includes

  • Treatment of high blood pressure
  • Treatment of underlying heart disease
  • Coronary angioplasty

Depending on the symptoms and severity of the underlying disorder, your doctor may recommend one of the following:

  • A pacemaker – which will provide the electrical impulse when the bundle branch block prevents the signal from reaching the desired location.
  • Cardiac resynchronization – commonly referred to as biventricular pacing. This is similar to having a pacemaker implanted. However, a third wire is implanted to ensure that both ventricles stay synchronized.

Bundle Branch Block Prevention

It is difficult to prevent bundle branch block after the underlying heart health issues have occurred. However, you can work to improve your overall heart health to avoid them and, if you already have bundle branch block, you can reduce the risk of making it worse.

Because bundle branch block makes it harder to pump blood through your circulatory system, strengthening your heart should be your priority. Make sure you are taking any medication and following your doctor’s advice on lifestyle choices. You can’t treat bundle branch block, but you can try to improve the underlying health condition.

There are things you can do to improve your heart health if you have a bundle branch block, or to prevent the condition from worsening. If you smoke, you are constricting your arterial blood flow, which can do further damage to your heart. In general, lower your intake of sodium, cholesterol and fat. Additionally, exercising, and maintaining a healthy blood pressure and weight are key preventive measures to reduce the conditions that lead to bundle branch block.

Last Reviewed:
September 18, 2016
Last Updated:
June 22, 2018