Figure 1. Surface electrocardiogram and activation map of atrial tachycardia (AT)
(A). Surface electrocardiogram of the AT. AT wave showed positive deflection in inferior leads and V1. AT cycle length was 230 ms. (B, C) The activation (white arrows) suggested a dual-loop tachycardia with a circuit on the mitral annulus (MA) and another around the left pulmonary veins (LPVs). Note that the lateral mitral isthmus was a common isthmus. The blue tags and numbers on the map show entrainment-pacing sites and the post-pacing interval minus the tachycardia cycle length. LAA, left atrial appendage; RPV, right pulmonary vein.