Discussion
Some studies have reported that left AT can originated from at mitral annulus, left atrial appendage (LAA) and pulmonary vein (PV)1,2. This is the first case of report AT originated from the ostium of anomalous drainage between the LIPV and LAA.
Focal AT showed circumscript “hot spot” area; however, in this case, the high-density map demonstrated a broad zone of almost identical activation times at the site of LAA ridge and LIPV inferior ostium using 3-D mapping, radiofrequency catheter ablation in this region failed to terminate the tachycardia. When the ABL catheter was dragged back and floated within the LA, the earliest activity was mapped with low contact force, the AT elimination was achieved by ablation at the site of earliest activity.
In conclusion, if a broad zone of almost identical activation times were mapped in patient with focal AT, the adjacent structure should be obtained simultaneously; the restructure of heart geometry may be helpful to demonstrate the anomalous structure and to guide the mapping and ablation procedure and precisely identify the origin site of AT.
Reference
1. Lee G, Sanders P, Kalman JM. Catheter ablation of atrial arrhythmias: state of the art.Lancet. 2012;380(9852):1509-1519.
2. Combes S, Albenque JP, Combes N, et al. An original management of focal atrial tachycardia originating from a giant left atrial appendage. HeartRhythm case reports.2018;4(4):135-137.
Figure1