To compare the pacing parameters of unipolar versus bipolar temporary ventricular epicardial pacing leads.Design:
Prospective Randomized Unblinded Controlled Study.Patients and Methods:
Fifty patients undergoing surgery for congenital heart disease who were anticipated to require temporary ventricular pacing leads were recruited preoperatively: 25 patients were randomized to receive unipolar temporary ventricular epicardial pacing leads; the remaining 25 were randomized to receive bipolar temporary ventricular epicardial leads. The baseline characteristics of the groups were similar. The pacing parameters were measured daily for up to first seven postoperative days (PODs) with the day of surgery recorded as POD 0.Results:
On the day of insertion, the mean pacing and sensing thresholds were similar for both unipolar and bipolar leads. Thresholds progressively deteriorated with each subsequent POD. By POD 4, the mean ± standard deviation pacing threshold of ventricular bipolar lead was 2.87 ± 0.37 mA compared with 5.6 ± 0.85 mA for the unipolar leads (P = 0.005). The decrease in sensing threshold of the unipolar ventricular pacing leads was significantly more than that of bipolar leads (by POD 5, 5.7 ± 2.64 vs 10.33 ± 2.8, P = 0.01).Conclusions:
Our study shows that the bipolar leads (Medtronic 6495, Medtronic Inc., Minneapolis, MN, USA) have superior sensing and pacing thresholds in the ventricular position in patients undergoing surgery for congenital heart disease when compared to the unipolar leads (Medical Concepts Europe VF608ABB, Medical Concepts Europe Inc., Buffalo, NY, USA).