Narrow QRS complexes within left bundle branche block in a patient with chest pain

Janos Tomcsanyi*, Mikos Somloi, Hein Wellens

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


We present the case of a patient with chest pain, palpitations, atrial fibrillation, left bundle branch block (LBBB) and occasional early narrow QRS complexes. An intracardiac study revealed rate-dependent LBBB with additional hidden rate-dependent slowing in the contralateral bundle branch, resulting in normalization of the early conducted QRS complexes. (c) 2020 Elsevier Inc. All rights reserved.

Original languageEnglish
Pages (from-to)36-38
Number of pages3
JournalJournal of Electrocardiology
Publication statusPublished - 2020


  • Rate-dependent bundle branch block
  • Premature beats

Cite this