A 64-year-old man presents to the emergency department with palpitations for 6 hours. ECG shows atrial fibrillation with a ventricular rate of 130 beats/min. He is haemodynamically stable with normal troponin and no heart failure signs. CHADS-65 factors include: age 64, no diabetes, no hypertension, no prior stroke or heart failure. According to the 2021 CAEP acute atrial fibrillation/flutter best practice checklist, which is the most appropriate plan regarding anticoagulation if he undergoes successful cardioversion today?