“…After functional reentry was induced and equilibrated for 5 -10 min, rapid point pacing trains (pulse amplitude < 1.4Â threshold to avoid cell damage, pulse duration = 10 ms) were applied from one of four peripheral sites (3, 6, 9 or 12 o'clock positions) in an attempt to stably perturb (terminate, accelerate, or decelerate) the reentry. To create different situations present during antitachycardia pacing by ICDs [1][2][3], pacing was applied relatively far (at least 7 mm) from the reentry core, and the onset time relative to local activation by reentry, the length (3 -25 pulses), and the rate (1.1 -1.5Â reentry rate) of the pacing train were arbitrarily varied. If reentry was terminated in one of the attempts, rapid pacing was reapplied at the center of the monolayer to induce another functional reentry, and the pacing protocol to perturb the reentry was repeated.…”