Bundle Branch Block: Causes, Symptoms, Diagnosis & Treatment

Bundle branch block (BBB) is a delay or blockage in the electrical signals that coordinate heart contractions. Normally, impulses travel down both bundle branches to the ventricles simultaneously. In BBB, one branch is impaired, causing the ventricles to contract out of sync.

Common Causes

• Coronary artery disease (CAD)
• Heart attack (myocardial infarction)
• Cardiomyopathy (heart muscle disease)
• Hypertension (high blood pressure)
• Diabetes
• Obesity
• Smoking
• Advanced age

Symptoms

Many people with BBB are asymptomatic. When symptoms occur, they may include:

• Chest pain
• Shortness of breath
• Lightheadedness or fainting
• Palpitations (irregular or rapid heartbeat)

Diagnosis

An electrocardiogram (ECG) is the primary diagnostic tool, revealing characteristic patterns of delayed conduction. Additional tests may include:

• Echocardiogram (heart ultrasound)
• Cardiac MRI
• Electrophysiological study (EPS)

Treatment Approaches

Treatment targets the underlying cause:

• Medications to improve heart function
• Angioplasty and stenting for blocked arteries
• Valve repair surgery if needed
• Lifestyle modifications: weight loss, healthy diet, exercise, smoking cessation

Prognosis

Outlook depends on the underlying condition. Most people with BBB live normal, active lives. However, some may develop complications like heart failure, requiring ongoing management.