Left Anterior Fascicular Block by ECG Finding

**Semantic type:** Finding

**Definition:** An electrocardiographic finding of a slightly widened QRS duration (typically less than 120 ms) with leftward frontal plane QRS axis and typically small Q waves in leads I and aVL. (CDISC)

**Synonyms:** - LAFB - LEFT ANTERIOR FASCICULAR BLOCK - Left Anterior Fascicular Block - Left Anterior Fascicular Block by EKG Finding - Left Anterior Hemiblock - Left Anterior Hemiblock - Left anterior fascicular block