Abstract 18335: Reversing Right Ventricular(RV) and Left Ventricular(LV) Pace Sense(PS) Leads in the Implantable Cardioverter Defibrillator(ICD) Header in Patients With the Medtronic 6949 ICD Lead and Bipolar LV Lead: A Method to Avert Consequences of the Common Failure Modes

Abstract

Background: Failure of the ring electrode of an implanted Medtronic Sprint Fidelis (6949 family) ICD lead commonly results in unnecessary shocks and can also lead to failure to pace. Placing a different PS lead will obviate this failure mode. We propose using a bipolar LV lead as the PS lead by connecting it to RV port, and connecting the PS part of the Fidelis lead to the LV port. Methods: Between 10/07 and 6/10 we identified 12 patients with Medtronic 6949 ICD leads and a Bipolar LV lead who underwent device procedures. All but one of the LV leads were Medtronic 4194. Criteria for swapping leads include: 1)adequate sensing by the LV lead; 2)no phrenic stimulation when pacing the LV lead; 3)no large T wave on the LV lead; 4) no failure of tip electrode or RV shocking coil of the ICD lead. The ring pacing electrode is not used, and the SVC coil is rarely needed for defibrillation. The ability to program around phrenic stimulation by reprogramming the LV pacing vector is lost. The LV port is programmed to pace Tip to RV coil. This effectively paces the ICD lead from tip to its coil. The RV port sensing configuration is left bipolar. Any LV-RV timing offset needs to be reversed. We turn off Ventricular Sense Response and LV lead capture management. Results: The first patient was not swapped but led to the criteria for future procedures. One patient had an LV R wave of 2.6 mv (threshold 3.5V) and was not swapped. Ten patients underwent the swap. Three had failure of the ring electrode of the Fidelis lead at the time of the procedure. Of the 10 patients, the LV R wave was 18.6 +- 8.2(mean +-SD), pacing threshold 1.26 +- .71, and RV R wave 19.8+-7.0, threshold 0.65+-.15. The patient who had a bipolar lead from another manufacturer developed noise on the LV lead and required reoperation. Another had T wave sensing when BiV paced and received a shock from double counting. This system is functioning after reprogramming. Thus 9 of the 10 have functioned satisfactorily. Conclusion: Placing a bipolar LV lead into the RV PS port, and the Fidelis pace/sense connector into the LV port with appropriate reprogramming may be an alternative to either lead extraction or placing a new PS lead or ICD lead in many CRT patients at the time of ICD generator change.