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Sequential Bilateral Bundle Branch Block During Dofetilide, A New Class III Antiarrhythmic Agent, In a Patient with Atrial Fibrillation |
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| Authors: | HARRY JGM CRIJNS MD J HERRE KINGMA MD † AT MARCEL GOSSELINK MD HW DALRYMPLE Ph D ‡ CEES DJ De LANGEN PhD KI LIE MD |
| Institution: | Departments of Cardiology, University Hospital Groningen;Departments of Clinical Pharmacology, University Hospital Groningen;Department of Cardiology. St. Antonius Hospital Nieuwegein, The Netherlands;Pfizer Central Research. Sandwich, Kent, United Kingdom |
| Abstract: | Sequential Bilateral BBB During Dofetilide. Introduction: I in mechanism of wide QRS complex tachycardias during dofetilide infusion was studied in a patient with atrial fibrillation. Methods and Results: Endocardial recording from the intraventricular conduction system showed that dofetilide caused "classic" aberrant conduction (Ashman phenomenon, typical QKS 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 QKS complex rhythms after dofetilide and possibly other "pure" Class III antiarrhythmics. |
| Keywords: | Aberrant conduction bundle branch reentry wide complex tachycardio antiarrhythmic therapy action potential prolengation |