224 RV Septal Pacing in Clinical Practice: Long-Term Results of the NOVUS Septal Study

Abstract

Right ventricular (RV) apical pacing is known to have a deleterious effect on hemodynamics, leading to consider the ventricular septum as a better alternative. The Novus Septal Study, aimed to evaluate the long-term performance of the Novus 5076 RV lead (Medtronic-USA), implanted at the RV septum in routine practice. Implantation of the RV septum lead was performed in 371 consecutive patients (Male 64%, average age 77 +/- 8 years). Pacing indication was advanced AVB (70%), SD (27%) and drug refractory heart failure in 3%. A single- dual- or triple-chamber pacemaker device was used in 17%, 80%, and 3% of cases respectively. Appropriate RV Septal lead positioning was validated by using per-operative LAO 30° projection (92%) and/or negative Q wave deflection in Lead I (67%). Time duration of RV lead placement was recorded at implant. Electrical RV lead parameters, including lead impedance, pacing thresholds and R wave sensing, were systematically monitored at 1 and 5 min after implantation and at 3 month follow up (FU). Long-term RV septal pacing could not be evaluated in 15 patients (4%), due to failure in positioning the RV lead at the septum in 10 (finally implanted at the apex), to lead dislodgement in 3, hight threshold in 1 and low sensing in 1, as recorded at 3 month FU. The remaining patients were subdivided into 3 subgroups, based on the methods selected to validate RV septal lead placement with the results as shown in table 1. * decreasing of impedance at 3 month FU for group 1 and 2 (p<0.001) ** increasing of the time duration for the group 3 vs 1 and 2. Long-term reliable RV septal pacing could be achieved in routine practice in the vast majority of patients (96%) using standard pacing or CRT indications. RV septal implantation duration may be longer using ECG criteria as compared to LAO 30° projection. RV Septal lead pacing and sensing thresholds remained stable over time, while lead impedance could decrease over time. Nb LAO 30 ° Neg Q Lead I threshold sensing impedance time duration (mn) 235 yes yes 1 mn 0.7 +/– 0.5 11.0 +/– 5.6 822 +/– 245 2’ 00 5 mn 0.6 +/– 0.4 11.3 +/– 5.9 788 +/– 218 3 month 0.5 +/– 0.2 11.5 +/– 5.3 570 +/– 167* 106 yes no 1 mn 0.6 +/– 0.3 10.3 +/– 5.6 793 +/– 190 1’ 58 5 mn 0.5 +/– 0.2 11.0 +/– 5.2 767 +/– 190 3 month 0.5 +/– 0.4 12.1 +/– 5.9 595 +/– 152* 13 no yes 1 mn 0.8 +/– 0.5 9.7 +/– 5.2 830 +/– 158 6’ 40** 5 mn 0.6 +/– 0.3 9.6 +/– 5.0 779 +/– 160 3 month 0.5 +/– 0.1 12.0 +/– 4.6 713 +/– 155