Author + information
- Received March 25, 2009
- Accepted April 26, 2009
- Published online March 9, 2010.
A 43-year-old man with paroxysmal atrial fibrillation (AF) and an implantable cardioverter defibrillator (ICD) placed for documented ventricular fibrillation (VF), presented with an ICD shock. Ventricular pre-excitation was not present. Interrogation of his ICD demonstrated AF (*) on the atrial electrogram (A Egm) with an irregular ventricular response (**) that spontaneously degenerated to VF (***), as observed on the ventricular electrogram (V Egm). AS and VS on the marker channel refer to atrial- and ventricular-sensed events. A successful ICD shock was delivered (not shown). The mechanism of the initial episode of VF in this patient was AF that, because of irregular R-R intervals, resulted in an R-on-T event that immediately preceded VF (***). Although AF is known to initiate VF, it rarely occurs in the absence of ventricular pre-excitation. Atypical triggers for VF, such as AF or monomorphic premature ventricular contractions, should be considered in patients with recurrent VF. Therapy for this patient included rate control and antiarrhythmic drug therapy with metoprolol and sotalol.
- Received March 25, 2009.
- Accepted April 26, 2009.
- American College of Cardiology Foundation