For ACLS purposes, we are primarily concerned with two basic types of pacing. The first, transcutaneous pacing, is an emergent procedure which uses 2 gel pads. One is placed at the 5th intercostal space mid-clavicular on the left side of the anterior chest wall, and the other in between the backbone and shoulder blade on the left side of the back. The electricity travels through the pads and innervates the heart. This form of pacing is temporary. It is especially uncomfortable for the patient, and therefore should only be used as a means of maintaining stability in the bradycardic patient while attempting other interventions, such as drug therapy, or preparing for a more permanent transvenous pacemaker which causes no pain.
Types of Rhythms Where Pacing Is Indicated
• Bradycardias that are unresponsive to drug therapy or are symptomatic
• 2nd degree heart block type II
• 3rd degree heart block
Atropine may be given to 2nd degree type II heart block or a narrow complex 3rd degree heart block as a trial but, when detected, the American Heart Association ACLS guidelines recommend that these dysrhythmias be managed by immediate application of the transcutaneous pacer and close observation of the patient for any signs of hemodynamic instability, e.g., shortness of breath – hypotension – altered level of consciousness – chest pain – pallor – nausea & vomiting – profuse sweating. If unstable and in 2nd degree heart block type II or 3rd degree heart block, then the pacer should be used to correct the rate only until transvenous pacing can be accomplished by a qualified person.
Remember from earlier in the reading that if a patient is bradycardic and hemodynamically unstable, as described in the previous paragraph, then transcutaneous pacing should be considered as a first line treatment.
Setting a transcutaneous pacemaker will be discussed in the electrical therapy station on day 1 of ACLS
Three Basic Rhythms
There are 3 categories of abnormal rhythms: too fast, too slow or none. Patients with any dysrhythmia may be stable, unstable or in cardiac arrest. Recognizing which type of patient you have will decide your treatment choices: medicine, electrical, and/or mechanical (BLS).
The first rhythm is too fast. Our goal is to slow it down. We have two methods to slow down a rhythm: electrical therapy and/or medicine. If the patient is hemodynamically stable, pharmacology should be the first line treatment. If our patient were hemodynamically unstable, synchronized cardioversion should be the first line treatment.
The second rhythm is too slow. Our goal is to speed it up. We have two methods of speeding up a rhythm: electrical therapy and/or medicine. If the patient is hemodynamically stable, pharmacology should be the first line treatment. If our patient were hemodynamically unstable, transcutaneous pacing should be the first line treatment.
Ventricular fibrillation, pulseless ventricular tachycardia, pulseless electrical activity and asystole are the dysrhythmias associated with cardiac arrest. As these are lethal dysrhythmias, management must be quick and aggressive.