Right bundle branch block or RBBB is a heart-related issue that normally doesn’t cause any symptoms unless you have some other type of underlying heart problem. While it’s rare in healthy young individuals, it does occur in older people.
Just exactly what is right bundle branch block? In simple terms, RBBB is a blockage of electrical impulses to the heart’s right ventricle. The right ventricle is located in the lower right part of the heart. With right bundle branch block, the electrical signal doesn’t travel to the right ventricle the way it should.
The signal does get there, but it’s slow in doing so when compared to the left bundle. This means the right ventricle contracts a little later than normal, causing the heart to eject less blood. As a result, the heart has to work a lot harder to pump blood throughout the body.
The reason the medical community calls the electrical pattern bundle branch block is due to the fact that the electrical impulses face a roadblock at the “bundle of His.” The bundle of His is an area of the heart where impulses to the right and left ventricles are conducted.
Prevalence of Right Bundle Branch Block
Some studies suggest that right bundle branch block prevalence is twice as high in men as it is in women. A study conducted in Sweden showed that men from the general population experience RBBB ranging from one percent at age 50 to 13 percent at age 80. The study involved 855 men. In other studies, including one conducted with over 18 thousand participants, a lower increasing prevalence of RBBB – from zero percent at age 30 to 4.1 percent in men and 1.6 percent in women between the ages of 75 and 79 – was observed.
What is Incomplete RBBB?
Incomplete right bundle branch block is diagnosed when a QRS complex reads 90 to 115 milliseconds. QRS complex is the combination of three deflections that show up on an electrocardiogram (EKG or ECG). In simple terms, it’s the main spike you see on an ECG line.
In healthy individuals, the QRS complex lasts 0.06 to 0.10 ms. Incomplete RBBB can cause symptoms that are similar to complete RBBB. While incomplete RBBB can be found when testing normal people, there are conditions that are associated with it, including straight back syndrome, right ventricular volume overload, and muscular dystrophy.
What Are the Causes of RBBB?
There is no one explanation for what causes right bundle branch block. RBBB can occur due to several different conditions. Sometimes, RBBB can happen following certain medical procedures and is temporary. The risk of right bundle branch block increases with the following:
- Heart disease from high blood pressure
- Chronic obstructive lung disease or COPD
- A blood clot in the lung, otherwise known as a pulmonary embolism
- Right-sided heart failure
- Cardiomyopathy, which is a disease of the heart muscle
- Idiopathic fibrosis or degeneration in the right bundle branch
- Cardiac surgery
- Myocarditis, which is an inflammation of a membrane surrounding the heart
- Aberrant ventricular conduction
- Congenital heart disease
- Coronary artery disease
- Heart attack
- Surgical procedures on the heart
It is important to note that the above are risk factors but sometimes, right bundle branch block happens on its own. Research into right bundle branch block causes is ongoing.
Complications of Right Bundle Branch Block
Reduced heart rate is the most common complication associated with right bundle branch block. This can lead to a person losing consciousness. Research suggests that people with RBBB that has developed following a heart attack are more likely to face complications, such as cardiac death. A number of studies have looked at the impact of RBBB on the risk of all-cause mortality, cardiac death, myocardial infarction (MI), and heart failure (HF).
The data showed that right bundle branch block was linked to an increased risk of all-cause mortality in the general population, MI and HF sufferers, and with an increased risk of cardiac death. Studies also show right bundle branch block is significantly associated with a risk of cardiac death in healthy men and women. There have been conflicting results in studies when it comes to the association between RBBB and all-cause mortality in women suggesting more studies are needed.
Symptoms of Right Bundle Branch Block
If you’re curious about right bundle branch block symptoms, the fact is, some people simply don’t have any while others experience syncope. Syncope is a term to describe fainting as a result of unusual heart rhythms. Some people with right bundle branch block go through pre-syncope. This means that they feel like they’re going to faint, but they never do.
It’s believed that right bundle branch block itself may not cause symptoms; that any signs of right bundle branch block are likely due to another heart-related problem on top of the RBBB.
Why You Should Be Worried About RBBB
Research shows that people with right bundle branch block who don’t experience symptoms are usually not associated with poor outcomes. Right bundle branch block significance is really tied to new RBBB in those with chest pain. This may be a sign of occlusion in the left anterior descending artery.
Occlusion (the blocking or closing of a blood vessel) is associated with the “widow-maker” infarction; a term that describes a high risk of death. It’s also important to understand that new right bundle branch block in patients who have difficulty breathing may indicate a pulmonary embolism.
Right Bundle Branch Block and Cardiac Efficiency
It’s possible to have left bundle branch block as opposed to right bundle branch block. In both cases, the heart’s two ventricles are stimulated one after the other instead of at the same time. This loss of coordination can reduce the efficiency of the heartbeat.
When it comes to right bundle branch block, reduction in the heart’s efficiency isn’t a serious concern. This means that even if someone experiences heart failure, the use of CRT is not recommended in those with RBBB. CRT stands for cardiac resynchronization therapy, which involves the inserting of electrodes in the ventricles to treat heart failure.
How to Diagnose Right Bundle Branch Block?
Doctors usually diagnose right bundle branch block through an ECG, since RBBB causes obvious changes in QRS complex. What they see is that the part of the ECG representing electrical impulse travel across the ventricles is wider than normal. In fact, with right bundle branch block, there is a specific pattern of widening of the QRS complex provided by a standard ECG. A lot of people find out they have RBBB when they are having an ECG done for some other reason. Aside from an electrocardiogram, doctors may conduct the following:
- Echocardiogram to check blood flow in the heart
- Testing to assess lung function
- Blood tests
Symptoms and RBBB treatment require careful consideration. While some people may not need treatment, others will. In those who have cardiovascular disease, there is a much greater risk of death, especially following a heart attack. There are cases where people with RBBB end up needing a permanent pacemaker, although this is rather rare. Normally, it’s required when there is an additional conduction problem along with right bundle branch block.
Many doctors tell their RBBB patients that they need to make lifestyle adjustments, such as quitting smoking, improving diet, or losing weight. They also recommend that sufferers monitor their symptoms carefully and see a doctor on a regular basis.
Generally speaking, doctors will treat the underlying condition associated with the RBBB. For example, if a person has high blood pressure, medications to help control it will be recommended. Treating the underlying condition might not get rid of right bundle branch block, but it can lessen the severity of it.
Right bundle branch block sounds frightening; however, in most cases, it’s not as serious as it sounds. When RBBB is diagnosed, the main objective will be to determine any underlying cardiac issues and then address them accordingly. It’s important if you receive a diagnosis of right bundle branch block to keep any doctors you visit informed of your condition.
- Take these tips to heart: How to better your heart health
- Yoga for heart health: Yoga poses to reduce the risk of heart disease