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.