Patients with AS can become severely compromised by loss of the atrial kick due to atrial arrhythmias or slow junctional rhythms. Patients with AI or MR can experience LV dilation in the setting of slow heart rates. A PA catheter with atrial and ventricular pacing capacity can be useful. In patients with intact conduction systems, rate manipulation can often be achieved pharmacologically. Transthoracic pacing elicits a ventricular response only and is indicated when the ability to rapidly open the pericardium and obtain epicardial pacing is limited, as occurs in reoperations or in patients with inflammatory pericardial disease. The loss of atrial contraction can lead to underfilling and hemodynamic compromise in patients dependent on the added preload from atrial systole. One of the other pacing modalities is preferable in this setting.

Before chest closure, and often prior to separation from CPB, epicardial pacing wires are placed. Atrial and ventricular wires are advisable in patients with diastolic dysfunction or who are otherwise disproportionately dependent on atrial contraction for adequate ventricular preload.

References

• Cronin B, Dalia A, Goh R, Essandoh M, Orestes O'Brien E. Temporary epicardial pacing after cardiac surgery. J Cardiothorac Vasc Anesth. 2022;36:4427-4439.
• Gaudino M, Di Franco A, Rong LQ, Piccini J, Mack M. Postoperative atrial fibrillation: from mechanisms to treatment. Eur Heart J. 2023;44:1020-1039.