Discussion
To the best of our knowledge, this is the first report of the CB ablation of focal AT originated in the tip of the LAA stump after LAA ligation. Due to the complex anatomic structure of the surgical LAA ligation stump, it is difficult to manipulate the catheter and deliver the effective energy to the target. Moreover, the thinness and fragility of the LAA stump increases the risks of cardiac perforation and tamponade. Successful electrical isolations of both RAA and LAA with CBs have been previously reported 4 5, which suggests that cryo-ablation could be an alternative treatment for these patients. However, LAA electrical isolation might increase the thromboembolic risk 6, further, the risk of embolic events increases in patients with incomplete surgical LAA ligation7. This case is especially at high thromboembolic risk for both incomplete LAA ligation and LAA isolation. So we deem it necessary that the patient take long-term anticoagulants. In conclusion, the CB2 electrical isolation could be safe and effective in treating focal AT originating in the tip of LAA stump after LAA ligation.