Qrs-duration in right venricular outflow tract

ORS duration my have an influence on the outcome of ventricular pacing, the influence of pacing site on QRS duration was investigated. Methods In 20 patients ( 5 female, 15 male) with a mean age of 61.1 years (11-93) the ventricular lead Medtronic SelectsecureTM 3830 was placed in the RVOT. Indication was SSS in 9, AV-block in 11 and AF in 1 patient. 11 leads were placed at the free wall and 9 leads at the septum of the RVOT. Measurements were taken with the Medtronic Analyzer. Results Intraoperative measurements were satisfying (Threshold 0.45 V (0.3-1.2), R-wave 10.8 mV (3.2-30), Impedance 772 Ohm (500-1721)) with no difference between free wall and septum. Total QRS duration of the intrinsic conducted QRS was 99 msec (50-160), and 139 msec of the paced QRS (100-200). The mean QRS prolongation by pacing was 40 msec (− 20 − +120). On free wall pacing site the mean prolongation was 49 msec, in septal pacing 33 msec. ![Figure][1] Conclusion RVOT pacing with the Selectsecure pacing system in feasible, the mean paced QRS duration in RVOT is 40 msec longer than the intrinsic, with shorter paced QRS at the septum, than at the free wall of the RVOT. [1]: pending:yes