Found on EKG. It is caused by a block in the "electrical wiring" of the heart which affects the appearance of the ekg. It most of the time indicates a significant problem with the heart but can at times be benign.
Its a electrical bl. Left bundle block refers to dysfunction in the electrical conduction pathway in the left branch of the left heart. It is electrical conduction block and can be a indication of additional heart issues and needs to be checked.