Coherent mapping with CARTO3 is useful to identify the critical isthmus of scar-related AT. However, it has also a pitfall. We present atrial tachycardia (AT) with pseudo micro-reentrant activation pattern created by coherent mapping on the right atrial free wall. It is possible that a pseudo tachycardia circuit was created due to the algorithm for the reconstruction of coherent mapping. Finally, entrainment mapping led to the identification of correct tachycardia circuit and termination of tachycardia by catheter ablation. When using coherent mapping with CARTO3, it is necessary to understand the pitfall well.

Superior vena cava (SVC) isolation improves outcomes in patients with atrial fibrillation (AF). However, right phrenic nerve (PN) injury is a major complication of this procedure. Repeated SVC isolation was performed due to recurrence of SVC-triggered AF. The right atrium (RA)-SVC activation map revealed that the propagation broke through the gap at the PN site from the RA to the SVC. To avoid PN injury, the SVC was isolated by making longitudinal lines on both sides of the PN in a cranial direction. This novel approach of SVC isolation may be an effective therapeutic option to prevent PN injury.