Left Anterior Fascicular Block (LAFB) ECG Review
A left anterior fascicular block, also known as left anterior hemiblock, occurs when the anterior fascicle of the left bundle branch is no longer able to conduct action potentials. The criteria to diagnose a LAFB, or LAHB, on ECG include the following: Left axis deviation of at least -45 degrees The presence of a qR complex in lead I and a rS complex in lead III …