Chapter 20

Transcutaneous cardiac pacing was introduced in 1952 by Zoll as a means of treating asystole and significant bradyarrhythmias.1 The high current densities at the skin surface that were required to pace the cardiac tissue in these early devices caused painful stimulation of the cutaneous nerves and underlying skeletal muscles.1 It was also difficult to determine when the heart was capturing due to significant muscular artifact. With the development of transvenous cardiac pacing leads in the 1950s, interest in external cardiac pacing waned. Although transvenous cardiac pacing has traditionally served as the mainstay of urgent temporary pacing, it requires significant time and operator skill to implement. This makes transvenous cardiac pacing less than ideal. As a result, in the 1980s, noninvasive pacing reemerged as a therapy for bradycardia and asystole.2,3 Technologic advances, including large adhesive electrodes and electrocardiographic (ECG) filtering, have largely overcome the early problems of extreme discomfort and interpretation of capture on the ECG.

Noninvasive transcutaneous cardiac pacing offers several advantages over invasive cardiac pacing techniques. It is comparatively easy to perform and requires minimal training. Thus, physicians, nurses, and paramedics can institute temporary cardiac pacing. Because it can be performed quickly, noninvasive cardiac pacing can be initiated almost immediately, eliminating the setup and the insertion time of invasive techniques. Noninvasive cardiac pacing carries none of the risks and complications associated with the invasive techniques. It is also more cost-effective than invasive pacing.

The heart is the only muscle of the body that generates its own electrical impulses. Its automaticity and subsequent rhythmic contractions propel blood to the tissues of the body. The initial cardiac impulse starts in the right atrium of the heart at the sinoatrial (SA) node. The sympathetic and parasympathetic nervous systems control the rate of impulse generation at the SA node. Once the electric stimulus is generated, it is conducted along the internal conduction pathways of the heart to the muscular atrial and ventricular walls. A delicate balance between electrolyte flux to create action potentials, myocardial integrity to allow impulses to become contractions, and an intact conduction system must be maintained. Conduction system problems are often the result of inadequate blood flow to the heart due to ventricular infarction and coronary artery occlusion. The blood supply to the conduction system of the heart originates from the right coronary artery. Occlusion of the right coronary artery can result in arrhythmias and conduction delays.

Transcutaneous cardiac pacing is a temporary method of cardiac pacing that is widely used in various clinical settings.4–9 It serves as a bridge to temporary transvenous cardiac pacing or to permanent pacemaker placement in patients with severe, symptomatic, or hemodynamically unstable bradyarrhythmias that do not respond to pharmacologic therapy. In bradysystolic cardiac arrest, pacing is not routinely recommended but should be used as early as possible after the onset of arrest.10–15 In patients with bradyarrhythmias that are expected to be transient, digoxin toxicity, or ...

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