CIEDs

CIEDs

1. Increasing numbers of patients with permanent pacemaker (PPM) and ICD devices are undergoing noncardiac surgery. Familiarity with the indications, functions, and perioperative management of these devices is essential.
2. PPMs are utilized in a variety of conditions where the patient’s native conduction is compromised or inadequate, including from structural or ischemic heart disease, infiltrative diseases, and postprocedural alterations in conduction pathways, among many others.
3. ICDs have significantly improved the mortality of patients at high risk for sudden cardiac death. The four key ICD functions are antitachycardia pacing (ATP), cardioversion, defibrillation, and backup pacing. The conventional ICD is implanted in the upper chest and is connected to one or two defibrillating transvenous leads that also have sensing and pacing capabilities.
4. Current PPM and ICD devices include traditional subcutaneous generators with transvenous leads that have single or dual chamber sensing and pacing and possibly antitachycardia therapies (ie, cardioversion-defibrillation, antitachycardia pacing), as well as newer technologies including leadless pacemakers and subcutaneous ICDs (see below).
5. Indications for PPM
   1. Symptomatic bradycardia.
   2. Third-degree (complete) AV block.
   3. Type II, second-degree AV block.
   4. Cardiac resynchronization therapy. Biventricular pacing to synchronize RV and LV depolarization in patients with symptomatic HFrEF (left ventricular ejection fraction [LVEF] ≤ 35%) with sinus rhythm and interventricular conduction abnormality (left bundle branch block [LBBB], QRS ≥ 150 ms).
6. Indications for ICD
   1. Primary prevention in patients at high risk for sudden cardiac death (LVEF ≤ 35%, at risk for ventricular tachyarrhythmias).
   2. Secondary prevention in patients with prior sudden cardiac death or unstable ventricular arrhythmias.