Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android


Cardiac pacing serves to maintain or restore myocardial depolarization and thus ensure adequate cardiac output. In the ED, pacing corrects rhythm disturbances or starts in anticipation of a conduction problem with hemodynamic impact.1

Indications for emergency pacing are provided in Table 33-1.

TABLE 33-1Indications for Emergency Pacing


Cardiac pacemakers deliver an electrical stimulus to the heart through electrodes, causing depolarization and subsequent cardiac contraction.2 The modern implanted pacemaker only stimulates the heart chamber if it does not recognize (sense) intrinsic electrical activity from that chamber after a selected time interval. Impulses go to the atria, ventricles, or both.

Components of a cardiac pacemaker include:

  • Pulse generator

  • Electronic circuitry for sensing and pacing

  • Lead system that connects the pulse generator to the electrode(s) and stimulates the myocardium

Relevant clinical details of these components are provided in Table 33-2.

TABLE 33-2Pacemaker Component Details


Transcutaneous pacing is an emergency technique frequently chosen in patients presenting with hemodynamically significant bradycardia because of its easy application. It uses externally (chest wall) applied electrodes to deliver an electric impulse to stimulate the myocardium. Transcutaneous pacers differ from standard pulse generators: The pulse duration of the externally stimulating impulse is longer and the current output higher than in internal pacing. Muscle contraction (usually the chest wall or diaphragm) is notable during external pacing, especially at high outputs, and may be painful. The muscle twitching makes palpation of the radial, carotid, or femoral pulse difficult. Finally, cardiac ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.