Mapping systems
A three-dimensional (3D) mapping system as the CARTO system (Biosense
Webster) or the EnSite system (Abott) was used. A 7-Fr 20-electrode
catheter (BeeAT, Japan Lifeline Co. Ltd, Tokyo, Japan) was placed around
the tricuspid valve annulus with the distal poles in the coronary sinus.
Following access to the LA, 3D geometry was created with a circular
mapping catheter (LASSO; Biosense Webster or Inquiry Optima; Abott) or
high-resolution catheter (PENTARAY; Biosense Webster or Advisor HD Grid;
Abott). Both color isochronal and propagation maps were generated. In
the bipolar potential peak-to-peak, the scar area was set as less than
0.1 mV, and the low voltage area was set as 0.1 to 0.5
mV.13 The gap in this study was defined as the
reconnection site where the Maze procedure was performed whether there
were slow conduction or not. Space surrounding the pulmonary veins was
counted as a gap.
We suspected approximate macroreentrant AT circuits using color-coded 3D
electroanatomic activation mapping.12, 14Macroreentrant AT was diagnosed when at least 2 atrial pacing sites were
within the circuit. Sites were considered within the circuit as
previously described.9 Non-macroreentrant-AT
was defined as occurring from a very small area (< 1 cm) and
propagating to the atrium in a centrifugal pattern.15,
16