TY - CHAP M1 - Book, Section TI - Cardiac Implantable Electronic Devices A1 - Daubert, James P. A2 - Prystowsky, Eric N. A2 - Klein, George J. A2 - Daubert, James P. PY - 2020 T2 - Cardiac Arrhythmias: Interpretation, Diagnosis, and Treatment, 2e AB - The very first cardiac implantable electronic devices (CIED) were single-chamber, ventricular pacemakers with epicardial leads that offered only asynchronous pacing. Essentially only fixed or intermittent complete AV block was treatable. Patients had Stokes-Adams attacks and life-threatening asystolic episodes. Transvenous leads led to less invasive implantation, and then dual-chamber pacing allowed restoration of AV synchrony for AV block patients and treatment of sinus bradycardia with AV pacing. In the 1980s, implantable defibrillators were inserted, initially for patients with recurrent sudden cardiac arrest (SCA, see Chapter 15). These followed a similar evolution from epicardial to transvenous leads and from single to dual chamber as technology developed. Indications expanded due to such progress and to clinical trials. More recently, biventricular pacing in select patients with LBBB has been used for cardiac resynchronization therapy (CRT). His bundle pacing has reemerged with the focus on more physiologic pacing. While transvenous leads offered easier implantation than epicardial ones, long-term risks include intravascular infection, and their removal in the event of either intravascular or pocket infection or failure, poses significant risks. Thus, miniaturized, leadless pacemakers and subcutaneous defibrillators have been developed. SN - PB - McGraw Hill CY - New York, NY Y2 - 2024/03/28 UR - accesscardiology.mhmedical.com/content.aspx?aid=1176523284 ER -