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.