1. Lilian Mantziari et al. JACEP 2015;1:411-420
Left Ventricular Tachycardia Maps are focused on the inferobasal LV wall. (A) Mapping of the full tachycardia CL (262 ms) shows a possible isthmus of conduction but the right part of it is confusing (dashed white arrow). Magnification of this area shows a lot of points with different colors resulting from incorrect annotation, see explanation in B. (B) The system automatically annotates the largest signal within the mapping window. When the mapping window includes the systolic activation, and this happens to be larger than the local diastolic electrogram, then the system automatically annotates the far field systolic potential (yellow dashed line). We can manually correct this by dragging the annotation to the near field signal (blue dashed line). A more efficient way to avoid this is to shorten the mapping window to exclude the systolic and focus on the diastolic part of the VT. (C) This map is automatically generated after we shortened the mapping window to 108 ms, focused on diastole, and it clearly shows a figure-of-8-shaped ventricular tachycardia (Online Video 2) with early diastolic potentials at the entry site (1), mid-diastolic potentials in the isthmus (2) and presystolic potentials at the exit site (3). (D) Substrate map of the inferobasal LV wall in SR. The scar threshold cutoff is reduced to 0.2 mV to reveal isthmuses of low voltage within the scar area. CL = cycle length; LV = left ventricle; SR = sinus rhythm.
Lilian Mantziari et al. JACEP 2015;1:
American College of Cardiology Foundation