Two different views of the macroreentry activation map. Initial
centrifugal propagation (black arrows ), subsequent propagation
(yellow arrows ), and final epicardial bypass (dotted white
arrows ) over the collision site (double black bars ) are
displayed. The values of PPI-TCL (white framed numbers ) are shown
at each site of entrainment pacing. Associated voltage map (0.2-0.5 mV)
and representative unipolar electrogram (white circle ) at the
breakthrough site are displayed. Distance from breakthrough to collision
site, area after 10 ms of centrifugal activation, and missing cycle
length are expressed. Lower right panel : location of the
breakthrough sites and type of macroreentry (disc for perimitral,circle for roof-dependent, and losange for CTI-dependent)
using this bypass. CTI, cavotricuspid isthmus; LAA, left atrial
appendage; LPV, left pulmonary veins; PPI, post-pacing interval; RPV,
right pulmonary veins; TCL, tachycardia cycle length.