A pacemaker is device placed in chest or abdomen to control abnormal heart rhythms. Indications of pacemaker, types of pacemakers, five letter code devised to simplify the naming of pacemaker generators, symptoms of pacer dysfunction, and common pacemaker dysfunctions are discussed in this chapter. Types of pacemaker are unipolar pacemaker, bipolar pacemaker, asynchronous/fixed rate, synchronous/demand, single/dual chamber, and programmable/nonprogrammable. Symptoms of pacer dysfunction are cyanosis, jugular vein distention, oliguria, dyspnea, orthopnea, altered mental status, vertigo/syncope, worsens with exercise, unusual fatigue, hypotension, and bradycardia.