Results
Six patients who had no inducible sustained VT from the RV apex/outflow
tract with at least 3 extrastimuli, but relatively easily induced VT
from the LV, basal RV, epicardium, or atrium are described. In 5 of
these patients, the site that induced VT was closer to the likely
reentry circuit region based on mapping and ablation. Computer
simulations illustrated that the spatial relation between the pacing
site and the entrance and exits of a reentry isthmus can determine the
ease of initiation of reentry by determining the time available for
recovery of excitability at the initial region of block.