Time-limited efficacy of pacing electrodes following open heart surgery

Temporary epicardial pacing electrodes have been utilised since the 1960s in the postoperative management of cardiac surgical patients, both as a diagnostic tool and therapeutic intervention. To determine the efficacy of the epicardial pacing wires over time after open heart surgery, 30 patients (20M/10F) who underwent coronary artery bypass surgery, were evaluated by standard 12-lead EKG, atrial electrogram, and atrial and ventricular pacing thresholds immediately after surgery and on postoperative day 5. Both atrial and ventricular pacing thresholds were significantly increased on postoperative day 5 as compared to baseline. The ability for effective AAI, VVI and DDD pacing was lost in 38.89 percent, 37.5 percent and 61.11 percent of patients, respectively, on postoperative day 5. We conclude that both atrial and ventricular pacing wires have limited efficacy after postoperative day 4 for pacing after open heart surgery due to a marked increase in pacing thresholds over this time period.