Key points about bifascicular block 

  • Bifascicular block is a heart conduction disorder where two of the three fascicles are blocked. 
  • It often occurs due to heart disease or structural damage to the conduction system. 
  • Symptoms may be mild or absent, but it can lead to dizziness, fainting or arrhythmias. 
  • Diagnosis is typically made with an ECG, showing specific abnormalities. 
  • Treatment can involve monitoring, medications or, in some cases, a pacemaker.
Common related conditions
Heart (Cardiovascular) Disease Heart Attack Heart Failure

Bifascicular block causes 

Bifascicular block may be caused by: 

  • Coronary artery disease or previous heart attacks, which can damage the conduction system. 
  • High blood pressure, leading to changes in the heart’s structure. 
  • Degenerative conduction system diseases, such as idiopathic fibrosis. 
  • Electrolyte imbalances affecting the heart's electrical system. 
  • Prior heart surgery or trauma. 

Bifascicular block risk factors 

Several factors increase the risk of developing bifascicular block, including: 
  • Coronary artery disease or history of heart attack. 
  • Hypertension (high blood pressure). 
  • Age, as the risk of degeneration in the conduction system increases with age. 
  • Family history of heart disease or conduction problems. 
  • Chronic conditions like diabetes or obesity. 

Bifascicular block symptoms 

Symptoms of bifascicular block can include: 
  • Dizziness, especially with physical activity or exertion. 
  • Fatigue or general weakness. 
  • Episodes of fainting or nearly fainting. 
  • Heart palpitations or an irregular heartbeat in some cases. 

Bifascicular block diagnosis 

To diagnose bifascicular block, doctors use: 
  • An electrocardiogram (ECG or EKG) to identify abnormal conduction patterns. 
  • An echocardiogram to assess the heart’s function and structure. 
  • Additional tests to rule out underlying heart conditions, such as coronary artery disease or heart failure. 

Bifascicular block treatment 

Treatment options for bifascicular block include:
  • Regular monitoring for those with mild or asymptomatic cases. 
  • Medications to treat underlying conditions like high blood pressure or heart disease.
  • In more severe cases, a pacemaker may be implanted to maintain a normal heart rate and prevent complications. 

When to Seek Care 

You should seek medical care if you experience: 

  • Symptoms like dizziness, fainting, or palpitations. 
  • A history of heart disease or if you have risk factors for heart disease. 
  • Difficulty exercising or shortness of breath, which could indicate worsening heart function. 
  • Any irregular heartbeat or significant change in your usual heart rhythm. 

Find a cardiologist near you

Bon Secours locations that can treat you