Introduction: The feasibility of entrainment of macroreentrant atrial arrhythmias such as atrial flutter is well documented. Recently, it has been shown that regional entrainment of atrial fibrillation is feasible in dogs.
Methods and results: Three patients with chronic atrial fibrillation underwent electrophysiologic evaluation with attempted entrainment of atrial fibrillation prior to successful endocardial atrial defibrillation. A 16-pole catheter was positioned in the trabeculated right atrium, and in two patients a multipolar catheter was positioned along the septum. In addition, two large surface area defibrillation catheters were placed, one in the lateral right atrium and one in the coronary sinus. Regional entrainment was attempted in the right atrium and from the catheter in the coronary sinus. Entrainment was achieved in the right atrium in all three patients over a cycle length range of 28, 17, and 13 msec, respectively, and over a radius of atrial tissue of at least 2.8 cm. Regional entrainment was demonstrated from the coronary sinus in one patient during simultaneous right atrial entrainment. Termination of atrial fibrillation during entrainment was not observed.
Conclusion: Regional entrainment of chronic atrial fibrillation is feasible in humans.