Most anesthesiologists understand that electromagnetic interference from monopolar electrosurgery may adversely impact the normal functioning of cardiovascular implantable electrical devices, including pacemakers and implantable cardioverter defibrillators. The most common consequences of electromagnetic interference are (1) pacing inhibition that could cause bradycardia and hypotension, and (2) inappropriate delivery of antitachycardia therapy, which can cause myocardial injury and might even increase mortality. Although previous studies have attempted to quantify how often intraoperative electromagnetic interference is detected by cardiovascular implantable electrical devices, the current study by Schulman et al.¹  examines this question prospectively and more thoroughly by defining three categories of electromagnetic interference: (1) any detectable electromagnetic interference; (2) electromagnetic interference that would have triggered antitachycardia therapy based on the implantable cardioverter defibrillator’s actual programming (“clinically meaningful”); and (3) electromagnetic interference that would have triggered antitachycardia therapy if conservative programming strategies intended to reduce the risk of inappropriate antitachycardia therapy had been employed. Implantable cardioverter defibrillators record all tachyarrhythmia events, and that information can be downloaded. Implantable cardioverter defibrillators manufactured by Medtronic (USA) and Boston Scientific (USA) can be programed to a “ monitor only” mode. This feature preserves the detection of arrhythmias, but prevents any therapies from being delivered, allowing safe use for surgery above the umbilicus. However, implantable cardioverter defibrillators by St Jude Medical (USA) and Biotronik (USA) do not have this capability, and therefore those devices could only be used for surgeries below the umbilicus.