A 74-year-old man with chronic atrial fibrillation underwent ablation under conscious sedation. After sheath removal from the left atrium, the patient flexed his thighs, resulting in a 'foetal position' developing tamponade due to an right atrial (RA) appendage perforation from sheath migration. This illustrates the importance of close monitoring during sedation weaning, recommending removal of all sheaths prior to sedation withdrawal.