Far field R wave sensing early after implantation-comparison of active and passive fixation leads

Abstract

With increasing use of Mode Switch algorithms, Far Field R wave Sensing (FFRS) has again become increasingly ImportanL We compared results eady after implantation with a passive and active fixation lead in a dual chamber pacing system allowing the programming of high atrial sensitivities (up to 0.1 mV), in avoiding FFRS. METHODS: 45 patients received a dual chamber pacemaker, Biob'onik Ac~os DR. In 29 patients, an affial bipolar preshaped tined J lead (BiotTonik Synox SX 53 JBP; ring-tip distance 14 mm) was used, 16 patients received an atrial bipolar active fixation lead (Biob'onik Elox 53 BP; dng-tip distance 10 ram). The ventricular lead was a unipolar lead (Biotronik Polymx PX 60-UP) in all cases. P and R wave amplitudes, thresholds and lead impedances ware measured. FFRS threshold was defined as the highest atTial sensitivity setting without Far Field detection of the paced R wave by the atrial sensing amplifier. During FFRS testing, simultaneous recording of atrial and ventricular IEGM, marker channel (A&V) and surface ECG was performed. Measurements ware made within 2 months postimplanL RESULTS: Results are summarized in table 1. Ta~el I E~p. Pwave N d ~ d ~ d NdaJle~:llmp. FFRSunipolm i FFRS / (mv~ (v at 0.4 ms) I (n) I (mV) ~po~ (mV) I ~ 2.89 +/-1.4 0.48 +/0.42 709 +/147 I 0.37 +h 0.22 p.21 .I.h 0.07 I ActhmFtxa0on I 2.33W-1.51 1.11 +/*0.43 378+/-38 I 0.49+1-0.27 p.24+h0.13 I P value ~ 0.2 0.003 <0.001 0.2 / 0.7 (P values = comparison of measumnlents in passive and aclfve fixation lead group) Both leads showed comparable results in terms of atrial sensing, whereas the atrial threshold was significantly higher with the active fixation lead, at least in the early phase after implantation. Lead impedance was higher with the passive (high impedance) lead. Venbicular measurements ware comparable in both groups. FFRS was significantly better in both groups with bipolar sensing compared to unipolar sensing. CONCLUSION: In the early phase after implantation (< 2 months), P wave sensing was comparable with both leads, but anal threshold was higher with the active fixation lead. Far Field R wave sensing was comparable in both leads and better with bipolar compared to unipolar sensing. HIGH IMPEDANCE LATEST GENERATION VENTRICULAR LEADS: COMPARISON BETWEEN TWO STEROID AND ONE NON -STEROID ELUTING LEAD WITH ULTRASMALL PACING SURFACE. D. Cornacchia E. Tampieri, S. Silvani, Cardiology Department, Ravenna, M. Nastasi, Cardiology Department Villabianca Bad, ITALY.