Left bundle branch block (LBBB) is a type heart block. It results from a problem with the electrical conduction system that enables the heart to beat. It may cause no symptoms, but an electrocardiogram (ECG) can detect it. Heart disease is one possible cause.
It does not always cause symptoms, but some people may feel lightheaded and develop chest pain. An ECG can record the heart’s rhythm and indicate the type of heart block a person has.
This article explains LBBB in more detail and looks at its causes, risk factors, symptoms, and more.
Bundle branch blocks occur when there is blockage or disruption in the heart’s electrical impulses. They cause those impulses to travel more slowly to the heart’s ventricles.
It can happen on the left and right side pathways of the ventricles, and doctors can see this blockage on an electrocardiogram (ECG) machine.
An LBBB can indicate an underlying heart condition. It causes an abnormal heart rhythm and is
A right bundle branch block can develop in people without any health conditions.
People with an LBBB have an
According to the National Library of Medicine (NLM), cardiac resynchronization treatment (CRT), one type of heart block therapy, can reduce death by
In rare cases, people may have congenital heart block, meaning they are born with this condition.
However, in most cases, heart block may develop during adulthood if a person has any of the following:
- Lyme disease
- heart attack
- heart surgery
- heart disease
- cardiomyopathies, or weakened heart muscles
Dilated cardiomyopathy is one of the primary causes of LBBB. It causes the heart chambers to enlarge so they can no longer contract effectively.
A 2017 review notes that LBBB is more common in older adults. It affects less than 1% of those under 50 and nearly 6% of people who are 80 years and older.
It can cause bradycardia, or a slow heart rate, which can lead to
- shortness of breath
- feeling weak
In one 2014 case study, a person with this type of heart block experienced chest pain.
Medical professionals may use the following tools to determine if a person has an LBBB.
An ECG measures the heart’s electrical impulses at rest or during exercise and can indicate the type of heart block present.
During the test, the doctors place electrodes on the person’s chest. The ECG produces a visual image of the heart rhythm.
People may also have to wear a portable ECG monitor so doctors can check the heart’s electrical activity over time.
An ECG test is painless, but people
A Holter monitor is a wearable device that can monitor the heart’s rhythm for
Implantable loop recorder
An implantable loop recorder is a heart recorder that medical professionals insert beneath the skin. It can record the heart rhythm for
There is currently
For example, a pacemaker may be an option for people who develop a heart block while having a heart attack. This can help regulate the heart rhythm, as a bundle branch block can cause bradycardia and the heart to become fragile.
However, if a person has alternating right and left bundle branch blocks, a doctor may also recommend a pacemaker.
- carrying a pacemaker ID card
- avoiding strong electrical fields
- going to regular pacemaker checkups
- keeping an eye on your heart rate
Research shows that there is no specific treatment for people with LBBB. However, a person may receive treatment if they have another heart condition.
- shortness of breath
- pain in the neck or jaw
- feeling lightheaded
- chest pain
A person should also consider seeing a doctor if they have an irregular heartbeat, high blood pressure, or a family history of heart disease.
An LBBB is a heart block condition mostly affecting older adults. It may also develop in people who have had a heart attack or heart surgery.
During an ECG test, a medical professional can examine the heart rhythm and determine if a person has an LBBB.
People should seek medical attention if they experience chest pain, shortness of breath, or lightheadedness.