Electrophysiological and clinical comparison of two temporary pacing leadsfollowing cardiac surgery

Temporary pacing leads are invaluable in diagnosis and treatment of arrhyth mia after cardiac surgery. The ideal lead possesses reliable pacing and sen sing capabilities throughout the postoperative period. Ease of handling and a low complication rate are essential. This study compares a new lead (Med tronic model #6492) to a temporary-pacemaker lead established in clinical u se (Medtronic model #6500). One lead of each type was placed in the right a trium and ventricle in 33 patients undergoing elective coronary revasculari zation. Pacing function was measured on the first and fourth postoperative days. Lead complications were documented, On day 1, there was no statistica l difference between lead types in terms of pacing (voltage threshold, curr ent threshold), impedance, or sensing (P wave amplitude, R wave amplitude). On day 4, both leads showed an increase in pacing threshold and a decrease in sensing ability. The only statistical difference between lead types was in atrial sensing on day 4, as measured by the P wave amplitudes (1.95 +/- 0.48 V for model 6492 vs 1.40 +/- 0.14 V for model 6500, P < 0.05). Two le ads of each model failed to pace in the ventricular position and one lead i n each model in the atrial position. There were no complications attributab le to either pacemaker lead. We found that both lead types were reliable an d functioned well. The Medtronic Model #6492 lead demonstrated better long- term sensing, although in this study the difference was not clinically sign ificant.