Electrophysiological and Hemodynamic Effects of Vernakalant and Flecainide During Cardiac Resynchronization in Dyssynchronous Canine Hearts

Lars B. van Middendorp*, Marc Strik, Patrick Houthuizen, Marion Kuiper, Jos G. Maessen, Angelo Auricchio, Frits W. Prinzen

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Introduction: Patients with heart failure and left bundle branch block (LBBB) are frequently treated with biventricular pacing (BiVP). Approximately one-third of them suffer from atrial fibrillation. Pharmacological conversion of atrial fibrillation is performed with drugs that slow ventricular conduction, but the effects of these drugs on the benefit of BiVP are poorly understood. Methods: Experiments were performed in dogs with chronic LBBB, investigating the effects of Vernakalant and Flecainide (n = 6 each) on hemodynamics and electrophysiology during epicardial (EPI) and endocardial BiVP. The degree of dyssynchrony and conduction slowing was quantified using QRS width and EPI electrical mapping. Results: Compared with LBBB, EPI and endocardial BiVP reduced QRS duration by 7% +/- 9% (P <0.05 compared with LBBB) and 20% +/- 13% (P <0.05 compared with LBBB, P <0.05 between modes), respectively. During BiVP, the administration of Vernakalant and Flecainide increased QRS duration by 20% +/- 14% (P <0.05 compared with predrug BiVP) and 34% +/- 10% (P <0.05 compared with prodrug BiVP, P <0.05 between drugs). left ventricular (LV) dP/dtmax decreased by 16% +/- 8% (P <0.05 compared with predrug BiVP) during Vernakalant and by 14% +/- 15% (P <0.05 compared with predrug BiVP) during Flecainide. The drugs did not affect the relative changes in QRS width and LV dP/dtmax induced by BiVP. Conclusions: Vernakalant and Flecainide decrease contractility, slow myocardial conduction velocity, and increase activation time. The electrical and hemodynamic benefits of BiVP are not altered by the drugs.
Original languageEnglish
Pages (from-to)25-32
JournalJournal of Cardiovascular Pharmacology
Issue number1
Publication statusPublished - Jan 2014


  • Vernakalant
  • Flecainide
  • cardiac resynchronization therapy
  • dyssynchrony
  • atrial fibrillation


Dive into the research topics of 'Electrophysiological and Hemodynamic Effects of Vernakalant and Flecainide During Cardiac Resynchronization in Dyssynchronous Canine Hearts'. Together they form a unique fingerprint.

Cite this