Right Ventricular Pacing and Sensing Function in High Posterior Septal and Apical Lead Placement in Cardiac Resynchronization Therapy

BackgroundThe conventional right ventricular (RV) lead position in cardiac resynchronization therapy pacemakers (CRT-P) is the RV apex (RV-A). Little is known about electrophysiological stability and associated complications of pacing leads in RV high posterior septal (RV-HS) position in CRT-P.MethodsTwo hundred and thirty-five consecutive CRT-P patients were included from 1999-2010. Pacing thresholds at 0.5 ms and 2.5 V, sensing electrograms and lead impedances were measured at implant and repeated 1,3,6,12,18 and 24 months after CRT-P. Electrophysiological measurements of leads located in RV-A and RV-HS were analyzed retrospectively. Bipolar RV leads were used, including high impedance leads, passive fixation and active fixation.ResultsRV pacing leads were implanted in RV-A (n = 79) and RV-HS (n = 156). Average RV pacing thresholds from CRT implant procedure to 24-month follow-up at 0.5 ms were 0.77 ± 0.69 V in RV-A and 0.71 ± 0.35 V in RV-HS (P = 0.31), and at 2.5 V were 0.06 ± 0.08 ms in RV-A and 0.07 ± 0.05 ms in RV-HS (P = 0.12). Average RV electrogram amplitudes from baseline to 24 months after CRT were 15.3 ± 6.9 mV in RV-A and 12.1 ± 6.0 mV in RV-HS (P = 0.55). Average RV impedances during follow-up were 850 ± 286Ω in RV-A and 618 ± 147Ω in RV-HS (P = 0.57). Similar RV lead revisions between RV-A and RV-HS were observed after 2-year follow-up (P = 0.55).ConclusionsThe RV-HS lead position demonstrated stable and acceptable long-term pacing and sensing function, with rates of complications comparable to conventional RV-A lead position in CRT. The RV-HS lead position is feasible in CRT-P.