What is the primary purpose of the pacemaker wires that can be inserted during a coronary artery bypass graft surgery?

The primary purpose of the pacemaker wires inserted during coronary artery bypass graft surgery is to provide temporary pacing of the heart if it develops bradycardia or a slow heart rate. These epicardial leads, which are attached to the heart's surface, can be connected to a temporary pacemaker to stimulate the heart to beat at an appropriate rate if the natural pacemaker function is compromised during or after the surgery.

In the immediate postoperative period, it is not uncommon for patients to experience fluctuations in heart rate as the heart adjusts to the surgical changes. If the heart rate falls below normal, the pacing wires allow for external electrical stimulation to establish a healthy rhythm until the heart resumes normal function. This application is crucial as sustained bradycardia can lead to inadequate cardiac output and pose significant risks to the patient.

While this highlights the function of epicardial leads, other options do not accurately describe their role. For example, pacemaker wires do not deliver shocks for tachycardia as indicated in one of the alternatives. Additionally, they do not provide continuous rhythms like a fully implanted pacemaker because they are temporarily used in response to specific needs. Lastly, while the notion of automatic defibrillation exists elsewhere in cardiac care, it does not apply