A health condition in which there is a blockage in the left ventricle of the heart is called left posterior fascicular block (LPFB). It prevents the heart from sending electrical signals, which causes an abnormal heartbeat. Most of the time, LPFB occurs due to coronary artery disease, but other heart diseases may also cause it. However, if LPFB appears along with a block in the right ventricle, it may cause serious problems.
In normal circumstances, the fascicles (signal carriers) around the front and back of the left ventricle work together. Thus, they tell your left ventricle to beat. Moreover, this condition can cause a partial or complete blockage. Generally, this condition occurs quite rarely, and it is mostly diagnosed in people with heart diseases. Additionally, a lot of people with LPFB also have a right bundle branch block that involves blocked electrical signals on the right side of the heart. When both conditions occur, there is an increased risk of fatal cardiac events (such as a complete heart block).
What Are The Symptoms of Left Posterior Fascicular Block?
While most of the time LPFB does not cause any symptoms, some people may experience the following ones. Examples include:
- Chest pain (angina)
- Heart palpitations
- Dyspnea (shortness of breath)
- Fatigue (extreme tiredness)
- Fainting (syncope)
- Dizziness
- Lightheadedness
If any of the previous symptoms occur, immediately contact your healthcare professional. Otherwise, it may lead to serious complications.
Causes and Risk Factors
This condition often happens due to other heart diseases, which cause damage to the heart. Check for the most common causes of LPFB below:
- Coronary artery disease – Reduced or a lack of blood flow to the heart due to clogged or blocked arteries may cause heart damage. It is one of the most common conditions that cause LPFB.
- Cardiomyopathy – This heart disease causes heart muscle stiffness, thickening, and enlargement.
- Hypertension (high blood pressure) – If this condition is left untreated, it may cause heart damage or weaken the heart muscle.
- Aortic valve disease – For example, leaks or narrowing in the aortic valve.
- Lenegre disease – It is an inherited disorder in which scarring negatively affects the conduction of the electrical signals in the heart.
- Lev’s disease – In people with this disorder, the nerve fibers become scarred. As a result, they are not able to send signals.
While anyone can develop this LPFB, doctors have identified some factors that could increase your risk. Check some examples below:
- Age – The risk of LPFB significantly increases with aging.
- Anatomical vulnerability – Normally, the left anterior fascicle is a thin and long structure that is naturally more prone to injuries or conduction blocks.
- Medical interventions and procedures (including transcatheter aortic valve replacement and surgical septal myectomy)
- Myocarditis (inflammation of the heart muscle)
- Family history – If you have a parent or sibling with LPFB, the risk of developing it significantly increases.
- Sex – Males are more likely to develop LPFB than females, according to some data.
What Are The Potential Complications of Left Posterior Fascicular Block?
Early detection and proper treatment may help reduce the risk or even prevent the following long-term effects (complications) of LPFB. Check some examples below:
- Congestive heart failure – Usually, this complication is associated with an increased risk of developing heart failure.
- Atrial fibrillation (AFib) – This is a serious condition that causes arrhythmia (irregular heart rhythm).
- Syncope – Disruptions in electrical signaling significantly increase the risk of advanced heart block, which may cause fainting or sudden dizziness.
- Advanced heart blocks – In some cases, this condition may progress to a more severe electrical disturbance (including a complete heart block), which is life-threatening.
- Pacemaker need – Sometimes, people may need a pacemaker to maintain the heart’s electrical system.
- Structural heart disease – Most of the time, LPFB happens along with CAD (coronary artery disease) or myocardial infarctions (heart attacks).
How to Prevent Left Posterior Fascicular Block?
One sure way to prevent LPFB is to prevent heart disorders that may cause it. That’s why doctors recommend routine checkups. They help identify heart problems in the early stages and treat them. In any case, if you already have heart disease, doctors may help reduce the risk or even prevent complications.
Diagnosis
First, doctors will perform a physical examination to check for abnormalities linked to the disease. During this procedure, they will listen to your heart by using a stethoscope and may also ask some questions about your medical history and symptoms. It may help get more information about your condition. However, to confirm or rule out LPFB, physicians often perform the following tests. Examples include:
- Electrocardiogram (ECG or EKG) – This is a quick and painless test used to measure the electrical activity of the heart. Usually, an EKG helps diagnose arrhythmia (irregular heart rhythm).
- Exercise stress test – During this test, doctors will perform an EKG while you are physically active to measure the heart’s activity under stress. Sometimes, LPFB is diagnosed during an exercise stress test.
In some cases, doctors may perform additional tests to check for complications of LPFB.
Treatment
Commonly, treatment for LPFB involves options to treat the underlying heart disease. Check some treatments below:
- Surgery
- Minimally invasive procedures
- Medications
- Lifestyle changes – These include quitting smoking, limiting or avoiding alcoholic beverages, performing physical activity, dietary changes, and others.
- Pacemaker – This is an implantable device used to monitor and maintain the electrical activity of the heart.
Furthermore, doctors do not prescribe any treatments if you have LPFB without other heart diseases.
Frequently Asked Questions
Can you live a normal life with a left posterior fascicular block?
Yes, most people with this condition don’t have symptoms. However, people can live a normal life even when they have symptoms by treating the underlying heart disease.
What is the prognosis for people with LPFB?
In general, the outlook for people with this condition is good, but early diagnosis and proper treatment are essential to prevent life-threatening complications. For example, heart attack, atrial fibrillation, and increased cardiovascular mortality.
Is left posterior fascicular block curable?
Typically, this condition is benign and, in most cases, does not need treatment. Commonly, it indicates an underlying heart disease. Therefore, doctors prescribe treatments for the underlying condition.
Can left posterior fascicular block cause a heart attack?
No, LPFB itself does not cause a heart attack. However, it is often associated with underlying heart conditions, such as coronary artery disease or a previous heart attack, which may increase the risk of future cardiac events.
Is left posterior fascicular block considered a serious condition?
LPFB alone is often not dangerous and may not cause moderate to severe symptoms. However, when it occurs alongside other conduction abnormalities, such as a right bundle branch block, it can increase the risk of more serious heart rhythm problems and require close monitoring.
How common is left posterior fascicular block?
LPFB is relatively rare compared to other conduction abnormalities because the left posterior fascicle has a broader blood supply and a thicker structure.
Can exercise worsen left posterior fascicular block?
In most cases, regular exercise does not worsen LPFB. However, if you have an underlying heart condition, your healthcare provider may recommend specific exercise guidelines based on your overall cardiovascular health.
Does left posterior fascicular block always require a pacemaker?
No. Most people with isolated LPFB do not need a pacemaker. A pacemaker may only be recommended if LPFB progresses to more advanced conduction disorders or causes severe symptoms related to abnormal heart rhythms.
Can left posterior fascicular block be detected during a routine checkup?
Yes. Since LPFB often causes no symptoms, it is frequently discovered incidentally during a routine electrocardiogram (ECG) performed for a physical examination, preoperative evaluation, or assessment of another heart condition.
Should people with left posterior fascicular block have regular follow-up appointments?
Yes. Even if LPFB does not cause symptoms, regular follow-up visits can help healthcare providers monitor for changes in heart function, detect underlying heart disease, and identify any progression to more serious conduction abnormalities. Ask your healthcare provider if you have any other questions.
