Phrenic nerve palsy (PNP) is still a cause for concern in Cryoballoon ablation (CBA) procedures. New surveillance techniques, such as invasive registration of the compound motor action potential (CMAP), have been thought to prevent the occurrence of PNP. | ECG-guided surveillance technique in cryoballoon ablation for paroxysmal and persistent atrial fibrillation: A strategy to prevent from phrenic nerve palsy