Author + information
- Received June 12, 1998
- Revision received February 10, 2000
- Accepted April 27, 2000
- Published online September 1, 2000.
- ↵*Reprint requests and correspondence: Dr. Albert L. Waldo, Division of Cardiology, University Hospitals of Cleveland, 11100 Euclid Avenue, Cleveland, Ohio 44106-5038
To test the hypothesis that when activation of Bachmann’s bundle (BB) is critical to the unstable reentrant circuits that maintain atrial fibrillation (AF) in the sterile pericarditis canine model, a lesion in BB would prevent induction of stable AF.
One mechanism of induced AF in this model is multiple unstable reentrant circuits, which frequently include BB as part of the reentrant pathway.
Simultaneous multisite mapping studies during AF and after ablation of BB were performed by recording (384 to 396 electrodes) from both atria and the atrial septum during six induced AF episodes in six dogs with sterile pericarditis. Activation maps of AF (mean duration, 24 ± 28 min) during 12 consecutive 100-ms windows were analyzed.
During AF, multiple unstable reentrant circuits (mean, 1.2 ± 0.2 per window; range, 1 to 4) were observed, 68% involving BB. Nonactivation zones (mean duration, 57 ± 16 ms in the right atrium and 53 ± 23 ms in the left atrium) observed during AF were reactivated by a wave front most often coming from the atrial septum via BB (right atrium, 62%; left atrium, 67%). After successful radiofrequency catheter ablation of the midportion of BB, AF >5 s was not induced in all dogs. Mapping studies of transient AF (≤5 s) induced after ablation showed neither reentrant circuits nor wave fronts activating the right atrium via BB.
In this AF model, catheter ablation of BB terminates and prevents the induction of AF by preventing 1) formation of unstable reentrant circuits that involve BB, and 2) activation of the atrial-free walls after a nonactivation period.
☆ This study was supported in part by grant RO1 HL38408 from the U.S. Public Health Service, National Institutes of Health, National Heart, Lung, and Blood Institute, Bethesda, Maryland. Dr. Kumagai is the recipient of a Postdoctoral Fellowship from the American Heart Association, Northeast Ohio Affiliate, Cleveland, Ohio.
Dr. Kumagai presented this paper as a finalist for the Young Investigator’s Award at the American College of Cardiology; 45th Annual Scientific Session held in Orlando, Florida, March 1996.
- Received June 12, 1998.
- Revision received February 10, 2000.
- Accepted April 27, 2000.
- American College of Cardiology