Left phrenic nerve injury during cryoballoon ablation of the left superior pulmonary vein.

Transcatheter ablation of the pulmonary veins (PVs) has been established as a therapeutic option for patients with symptomatic atrial fibrillation. Cryothermal energy is an alternative energy source that has been developed to overcome some of the disadvantages of radiofrequency ablation. The major complication of the cryoballoon technique seems to be right-sided phrenic nerve injury (PNI) following ablation of the right superior PV. This case report describes a left-sided PNI after cryoballoon ablation of the left superior PV.