Temporary Pacemaker

Once a patient has a temporary pacemaker inserted, checking its threshold parameters and assuring proper functioning is the nurse's responsibility. To do this you need to understand the concepts and principles of cardiac pacing and how to adjust the settings on the pulse generator.

Let's start with cardiac pacing. A temporary pacemaker is typically indicated for patients with symptomatic bradycardias, such as slow escape rhythms, conduction defects, and heart blocks. The tip of the pacing catheter, or lead wire, sits against the inner wall of the right atrium, right ventricle, or both, depending upon the type of pacemaker placed—atrial, ventricular, or AV sequential, for example. The proximal end of the catheter is attached to the pulse generator.

The pulse generator houses the pacemaker's controls and energy source. Electricity is delivered to the myocardium via the lead wire at a prescribed rate. Always check to see that the rate prescribed matches the rate set on the pulse generator.

The mode of pacing can be set on either demand or asynchronous. When it is set on demand, the pacemaker senses the heart's impulses, and paces only when the patient needs it. When it's in the asynchronous mode, the pacemaker fires at a fixed rate regardless of the heart's ability to generate impulses.