PO-04-018 RECOGNITION AND INTERPRETATION OF IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR INTERVAL CHANGES ON REMOTE MONITORING FOLLOWING A CARDIAC CONTRACTILITY MODULATION IMPLANT.

Abstract

Cardiac contractility modulation (CCM) devices aim to improve the quality of life in chronic heart failure patients by delivering an electrical stimulus during the absolute myocardial refractory period in hopes of improving contractility without additional myocardial oxygen consumption. With 7,000 patients receiving the benefits of CCM by May 2022, it becomes increasingly important to remain educated regarding purpose, functionality, and potential for implantable device interactions. Investigate abnormal implantable cardioverter-defibrillator (ICD) remote monitoring (RM) transmissions to eliminate device interactions. Patient (73 yr) received an ICD in 2017 for non-ischemic cardiomyopathy and ventricular tachycardia and is compliant with RM and in-person follow-up. A CCM device was implanted December 2021 with no ICD re-programming post-iterative testing. Multiple RM transmissions reviewed January – May 2022 noted changes (Table 1), including “noise” visualized on both atrial and ventricular channels; however, only atrial over-sensing occurred (Figure 1). The RM team inquired about possible external stimuli in May 2022’s transmission and from clinic correspondence, learned of the patient’s CCM implant. Patient was seen in-clinic with appropriate company representatives present. ICD re-programming completed: Post Ventricular Atrial Blanking shortened to 110 ms; PVAB Method to Absolute; V Blanking post VS increased to 140 ms, and VF detection decreased to 214 bpm. CCM changes made: 8 hours to 9 hours and pulse delivery from 40 ms to 35 ms. ICD changes observed via RM over 5-month period post-CCM implant include false-positive (FP) AT/AF detections, short V-V intervals, and PVC burden (unclear if accurate or FP due to RV over-sensing). The increased sensed R-waves initially assumed to be an inappropriate measurement of CCM output were 15mV via in-office automatic testing. Changes recognized via RM allowed the clinic to non-urgently schedule simultaneous assessment and adjustment of both implanted devices with the hope of preventing over-sensing, specifically RV over-sensing resulting in inappropriate ICD therapies. While an in-office ICD evaluation did occur immediately post CCM implant, it is imperative to continue RM to assess for concomitant device interactions.Tabled 1Table 1DateRV SensingShort interval counter (SIC)PVC Runs/Singles CountEpisodes11/26/21 2:28 am RM3.6mV0Runs 7.3Singles 126.6 since 11/07/21No episodes01/18/22 in-clinic4.1mVnot available (n/a)n/aNo episodes01/18/22 8:09 pm RM4.1mV127 since 12/16/21Runs 5.6Singles 108.7 since 12/18/21No episodes01/18/22 8:12 pm RM4.1mV127 since 12/16/21Runs 5.6Singles 108.7 since 12/18/21No episodes01/20/22 6:11 pm RM3.5mV10 since 01/18/22Runs 2.2Singles 59.5 since 01/18/22No episodes02/25/22 1:23 am RM3.9mV158 since 01/18/22Runs 7.1Singles 110.8 since 01/20/221 AT/AF (FP)05/26/22 3:34 am RM15.6mV1060 since 01/18/22Runs 18.4Singles 161.3 since 02/25/221 high rate NST (true positive)4 AT/AF (FP)05/31/22 in clinic16.5mVn/aRuns 15.9Singles 150.7 since 01/18/22n/a Open table in a new tab