QTc interval evaluation in patients with right bundle branch block or bifascicular blocks

Damir Erkapic*, Gerrit Frommeyer, Niklas Brettner, Korkut Soezener, Harry J. G. M. Crijns, Melchior Seyfarth, Christian W. Hamm, Harilaos Bogossian

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Background The right bundle branch block (RBBB) and the bifascicular blocks affect QRS duration in the right precordial leads, which are usually used for QT interval determination. Up to now, there is no clear recommendation how to determine QT interval in patients with RBBB or bifascicular block.

Hypothesis The hypothesis of the present study was to evaluate the feasibility of a simple formula for RBBB and bifascicular block correction, thereby making it easier to determine the QTc interval.

Methods In patients with intrinsic QRS duration

Results A total of scheduled 71 patients were included in this prospective multicenter observational comparative study. Compared to intrinsic QTc interval, the mean Delta QTmc interval by combination of the Bogossian and the Hodge formulas was -3 +/- 24 ms in RBBB + LPFB (P = .44) and -6 +/- 25 ms in RBBB + LAFB (P = .15). The Bogossian formula showed a significant deviation from the actual QTc interval with both the Bazett and the Fridericia formulas.

Conclusion In combination with the Hodge formula, the Boggosian formula delivered the best results in comparing the true QTc interval in narrow QRS with the QTmc interval in the presence of a bifascicular block.

Original languageEnglish
Pages (from-to)957-962
Number of pages6
JournalClinical Cardiology
Issue number9
Publication statusPublished - Sept 2020


  • bifascicular block
  • Bogossian formula
  • long QT
  • QT formula
  • QT prolongation
  • right bundle branch block
  • RISK

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