Association between left bundle branch block and anterosuperior hemiblock

Revisiting evidences


  • José Nunes de Alencar Neto


Bundle-Branch Block, Electrocardiography, Vectorcardiography


The concomitant diagnosis of left bundle branch block and anterosuperior hemi-block is controversial among cardiologists, especially when there is left vectorcardiographic axis deviation. In a brief literature review, we describe His bundle’s anatomy and its trifascicular nature, we present Medrano’s quadrifascicular theory and revise the
diagnostic criteria of these two electrocardiographic entities. We conclude that concomitant block might be found in cases of post-divisional bifascicular blocks with greater involvement of the anterosuperior hemiblock. On the other hand, the cardiologist must keep in mind that there are other causes of left axis deviation in the presence of left bundle branch block, such as: inferior infarction, anterior-septal and lateral infarction, and atypical bypass tracts.


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How to Cite

Nunes de Alencar Neto, J. (2018). Association between left bundle branch block and anterosuperior hemiblock: Revisiting evidences. JOURNAL OF CARDIAC ARRHYTHMIAS, 31(1), 8–12. Retrieved from



Review Article