Arrhythmias can occur following cardiac surgery. When a patient's heart is not in sinus rhythm, cardiac output is not optimal, putting the patient’s life at risk.
Temporary pacing leads are often attached to the myocardium at the end of the cardiac surgical procedure. Once the leads are placed and connected to an external pacing device, the electrical activity of the heart can be sensed and paced when necessary.
Temporary pacing leads can be placed on the right atrium, the right ventricle, or both. When only the atrium or the ventricle is paced, this is referred to as single-chamber pacing. Single-chamber pacing almost invariably refers to placing the temporary pacing lead on the right ventricle to ensure that the ventricles adequately pump blood through the body. However, if the ventricles are not synchronized with the atria, or if the atria are not pumping as effectively as they should, this often results in hypotension or low cardiac output. Therefore, ventricular or single-chamber pacing alone does not always result in optimal cardiac output.
Pacing of both chambers is referred to as dual-chamber pacing. Dual-chamber pacing ensures that the atria and ventricles are synchronized. As a result, cardiac output is increased with no appreciable increase in workload to the ventricle. Although temporary pacing lead placement on the atrium may be more difficult, atrial pacing can be a lifesaving measure, especially when ventricular pacing is ineffective.1
Molina JE. Temporary Dual-Chamber Pacing After Open Cardiac Procedures. Medtronic News. Spring 1989.