Circuit Localization of Unstable Intramural Ventricular Tachycardia
Using Live Directional Activation Mapping; A Potential Mapping Tool for
Intramural Arrhythmias
Abstract
Introduction: Intramural ventricular tachycardia (VT) remains a
challenge because of the difficulty in accurately localizing its focus
from the surface of the myocardium. Methods and Results: An
83-year-old man with non-ischemic cardiomyopathy experienced unstable
sustained monomorphic VT. Suboptimal pacemaps in the epi/endocardium and
the absence of diastolic or presystolic local electrograms indicated the
intramural focus. Despite the very short recording time, the live
activation directional mapping (AD) showed a centrifugal activation
pattern at the possible exit site of the epicardium. Based on these
findings, bipolar ablation was performed between the epi- and
endocardium and successfully eliminated the unstable intramural VT.
Conclusions: AD is a time-agnostic live directional mapping
application that may provide the information of intramural activation
apart from the myocardial surface.