In a patient with a DDD-R pacemaker wired to asynchronous mode (DOO) with increased native heart rate during surgery, which action is most appropriate?

In a patient with a DDD-R pacemaker wired to asynchronous mode (DOO) with increased native heart rate during surgery, which action is most appropriate?

• A. Turn off pacemaker for duration of case
• B. Administer lidocaine
• C. Administer esmolol
• D. Change volatile from isoflurane to desflurane and deepen anesthetic

Answer: (C)

When a pacemaker is in asynchronous pacing, it delivers paced impulses without sensing the patient’s own heart activity. If surgery provokes a sympathetic surge, the native heart rate can rise while the pacemaker keeps pacing at a fixed rate, leading to a mismatch that can cause tachycardia and hemodynamic instability. The best way to handle this is to blunt the sympathetic response and lower the heart rate with a short-acting beta-blocker like esmolol. Its rapid onset and quick offset let you control the rate intraoperatively without long-lasting effects if you need to adjust. Turning the pacemaker off is not ideal because it would remove pacing support and leave you with the patient’s intrinsic rhythm, which could be too slow or unstable under anesthesia. Lidocaine targets ventricular ectopy and arrhythmias, not the problem of rate control from sympathetic stimulation. Switching to desflurane and deepening anesthesia might not reliably reduce tachycardia—desflurane can even increase heart rate in some patients—so it’s not the best solution for this scenario.

When a pacemaker is in asynchronous pacing, it delivers paced impulses without sensing the patient’s own heart activity. If surgery provokes a sympathetic surge, the native heart rate can rise while the pacemaker keeps pacing at a fixed rate, leading to a mismatch that can cause tachycardia and hemodynamic instability. The best way to handle this is to blunt the sympathetic response and lower the heart rate with a short-acting beta-blocker like esmolol. Its rapid onset and quick offset let you control the rate intraoperatively without long-lasting effects if you need to adjust.

Turning the pacemaker off is not ideal because it would remove pacing support and leave you with the patient’s intrinsic rhythm, which could be too slow or unstable under anesthesia. Lidocaine targets ventricular ectopy and arrhythmias, not the problem of rate control from sympathetic stimulation. Switching to desflurane and deepening anesthesia might not reliably reduce tachycardia—desflurane can even increase heart rate in some patients—so it’s not the best solution for this scenario.