Lüker J, Kuhr K, Sultan A, et al. - Researchers evaluated external vs internal cardioversion in patients with implantable cardioverter-defibrillators (ICDs), for the first time ever in a randomized trial, hypothesizing the noninferiority of external cardioversion to internal cardioversion for safety, and superiority for successful restoration of sinus rhythm. In this study, 230 consecutive patients with ICD undergoing elective cardioversion for atrial arrhythmias were included and were randomized 1:1 to either internal or external cardioversion. Findings revealed the superiority of external cardioversion as far as the restoration of sinus rhythm was concerned. In selected ICD patients presenting for electrical cardioversion, an internal shock attempt may be reasonable, as indicated by the unmasking of silent lead malfunction in the internal cardioversion group.