Ripple mapping-guided atrial tachycardia ablation following open-heart surgery

Ripple mapping can make the visualization of activation conduction on a 3-dimensional voltage map and is useful tool for scar-related organized atrial tachycardia (AT). This study sought to assess the efficacy of ripple mapping for interpreting reentrant circuits and critical isthmus in postoperative ATs. 34 consecutive patients with a history of mitral valve surgery (mean age, 54.5 ± 12.4 years) underwent high density (HD) RM during ATs with CARTO3v4 CONFIDENSE system. The voltage activation threshold was determined by RM over a bipolar voltage map. The identification of underlying mechanisms and ablation setting was based on RM without reviewing activation mapping. A total of 41 ATs (35 spontaneous, 6 induced) were characterized. 39 reentry circuits were successfully mapped (cycle length, 256 ± 43 ms). Of the 41 ATs, 28 were confirmed by ripple mapping alone (68%), and 12 (29%) by ripple mapping and entrainment mapping. Of 12 ATs in the left atrium, 9 (75%) needed entrainment to confirm, compared with 5 (17.8%) in the right atrium. Primary endpoint after initial ablation set was achieved in 32 of the 34 patients (94.1%). Freedom from atrial arrhythmias was 79.4% after the follow-up of 12 ± 5 months. Of the seven patients with recurrence, three underwent the repeated catheter ablation. Ripple mapping precisely delineated reentrant circuits in post-cardiac surgery AT resulting in a high success rate of ablation. Entrainment maneuvers remain useful for elucidation of complex AT circuits.