What is a hemiblock?

What is a hemiblock?

• A. Complete block of the right bundle branch
• B. Blockage of the anterior or posterior division of the left bundle branch
• C. Partial block of the right bundle branch
• D. Blockage of both the anterior and posterior division of the left bundle branch

Answer: (B)

A hemiblock refers to a specific type of conduction disturbance within the heart's electrical system, particularly affecting the left bundle branch. It occurs when there is a blockage in one of the divisions of the left bundle branch, which can be either the anterior or the posterior division.

This disruption impacts the normal conduction pathway of electrical impulses in the heart, which can lead to altered patterns on an electrocardiogram (EKG). Hemiblocks are classified based on which division of the left bundle branch is affected. For instance, an anterior hemiblock affects the anterior division, while a posterior hemiblock involves the posterior division.

Understanding that a hemiblock is not a complete blockage of the right bundle branch or both divisions of the left bundle branch is crucial. Complete blocks typically refer to more severe disruptions in conduction, while a hemiblock specifically describes partial blockages involving the left bundle branch’s subdivisions.