“…Because "complete" LBBB may often be not truly complete, and because the QRS duration in LVH can probably be greater than 120 ms without a localized lesion in the left bundle, the distinction between these two entities may be difficult to define. 43 A left atrial P-wave abnormality 38,39,41 and a QRS duration greater than approximately 155 ms, as well as precordial lead voltage criteria, 35,38 -42 tend to have relatively high specificity for LVH in the presence of LBBB. In patients meeting these specific criteria, it is reasonable to diagnose LVH, even though the sensitivity is low.…”