Why the study?
What is the mechanism of wide QRS complex tachycardias during dofetilide infusion in a patient with atrial fibrillation?
What is the mechanism of wide QRS complex tachycardias during dofetilide infusion in a patient with atrial fibrillation?
Dofetilide can cause wide QRS complex rhythms mimicking ventricular ectopy through aberrant conduction and sequential bilateral bundle branch block, which is important for clinical assessment of arrhythmias after administration of pure Class III antiarrhythmics.
Alerts clinicians to misclassifying dofetilide-induced aberrancy as ventricular ectopy in AF; case report leaves broader applicability open.
INTRODUCTION: The mechanism of wide QRS complex tachycardias during dofetilide infusion was studied in a patient with atrial fibrillation. METHODS AND RESULTS: Endocardial recordings from the intraventricular conduction system showed that dofetilide caused "classic" aberrant conduction (Ashman phenomenon, typical QRS morphology) at high prematurity ratios (preceding interval = 1.78 x coupling interval--290), thus mimicking ventricular ectopy. In addition, there was frequent sequential bilateral bundle branch block, caused by a significant difference in preceding bundle-to-bundle intervals (mean difference +/- 1 SD: 74 +/- 26 msec). CONCLUSION: The present findings may prove helpful in the clinical assessment of wide QRS complex rhythms after dofetilide and possibly other "pure" Class III antiarrhythmics.
No takes yet. Share an insight, caveat, or question.
Crijns et al. (1993) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: