Pseudo-focal AT ablation
The ablation target was determined at the discretion of each operator.
Two types of strategies were distinguished: (1) obstructing the
endocardial emergence with a patchy lesion at the breakthrough site; or
(2) blocking an anatomical isthmus of the circuit with a linear lesion,
either downstream or upstream of the breakthrough site to avoid or to
transect the epicardial bypass. In the latter case, and if the
macroreentry was supported by the CS-GCV bundle or the VOM bundle, they
were respectively eliminated by endovascular radiofrequency application
or by retrograde ethanol infusion as previously
described.8,9 AT termination was defined as the
resumption of sinus rhythm or total alteration of the tachycardia
circuit during ablation.