Implantable Cardiac Pulse Generators: Pacemakers and Cardioverter-Defibrillators

Abstract

Background: Cardiac implantable electronic devices (CIEDs), including pacemakers, implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy (CRT) devices, are increasingly encountered in perioperative patients. Electromagnetic interference, pacing dependence, magnet response, and changes in antitachycardia therapy may pose clinically significant risks if not recognized. Objective: To summarize the principles of CIED function and develop a practical approach to preoperative evaluation, intraoperative and postoperative management, special procedures, and evolving CIED technologies. Methods: This article is a narrative review based on the provided textbook-reading chapter, while retaining the supporting literature cited in the source. The synthesis was organized according to device type, electromagnetic interference risk, magnet-use versus reprogramming strategies, monitoring, emergency protocols, specific high-risk procedures, and developments in leadless devices. Results: Perioperative assessment should identify the CIED type and manufacturer, most recent interrogation results, battery longevity, pacemaker dependence, intrinsic rhythm, pacing thresholds, and magnet response. The risk of electromagnetic interference is primarily associated with monopolar electrocautery, particularly when the current pathway is above the umbilicus or close to the generator/leads. In patients with an ICD, antitachycardia therapies should be disabled when EMI risk is present, whereas pacemaker-dependent patients may require asynchronous pacing. Magnet application has different effects on pacemakers and ICDs; therefore, the device response must be known in advance. Monitoring of mechanical capture using plethysmography or an arterial waveform is important during surgery. After surgery, suspended therapies should be promptly restored, and interrogation should be performed in high-risk conditions. Conclusion: Perioperative CIED management should be individualized according to device characteristics, pacing dependence, surgical site, and EMI risk. Communication between the anesthesiology team and the CIED team is a central component in preventing underpacing, inappropriate ICD therapy, device reset, and hemodynamic compromise.