From the Guidelines
In cardiology, LAFB stands for Left Anterior Fascicular Block, a conduction abnormality characterized by specific changes on an electrocardiogram (ECG), including left axis deviation, small Q waves in leads I and aVL, and small R waves in leads II, III, and aVF, as defined by the 2019 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1.
Key Characteristics of LAFB
- Frontal plane axis between 45° and 90°
- qR pattern in lead aVL
- R-peak time in lead aVL of 45 ms or more
- QRS duration less than 120 ms
Clinical Implications
LAFB is often asymptomatic and may be found incidentally during routine ECG testing. However, it may indicate underlying heart disease, such as coronary artery disease, cardiomyopathy, or degenerative conduction system disease. Further cardiac evaluation may be warranted depending on the clinical context and patient's history.
Diagnosis and Management
The diagnosis of LAFB is based on ECG criteria, and management is generally focused on underlying conditions rather than the block itself. According to the 2019 guideline, patients with LAFB do not typically require specific treatment, but may benefit from further evaluation and monitoring for underlying cardiac disease 1.
From the Research
Definition of LAFB
- LAFB stands for Left Anterior Fascicular Block, a heart disease identifiable from an abnormal electrocardiogram (ECG) 2.
Clinical Significance
- LAFB is associated with an increased risk of heart failure and has been linked to coronary artery disease (CAD) and myocardial infarction (MI) 3.
- LAFB can also be a sign of left ventricular depolarization delay secondary to extensive ischemia in left main coronary artery disease 4.